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hellwig |
//
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// cpu_core.v -- the ECO32 CPU core
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//
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`timescale 1ns/10ps
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`default_nettype none
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module cpu_core(clk, rst,
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bus_stb, bus_we, bus_size, bus_addr,
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bus_din, bus_dout, bus_ack, bus_irq);
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input clk; // system clock
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input rst; // system reset
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output bus_stb; // bus strobe
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output bus_we; // bus write enable
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output [1:0] bus_size; // 00: byte, 01: halfword, 10: word
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output [31:0] bus_addr; // bus address
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input [31:0] bus_din; // bus data input, for reads
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output [31:0] bus_dout; // bus data output, for writes
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input bus_ack; // bus acknowledge
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input [15:0] bus_irq; // bus interrupt requests
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// program counter
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wire [31:0] pc; // program counter
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wire pc_we; // pc write enable
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wire [2:0] pc_src; // pc source selector
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wire [31:0] pc_next; // value written into pc
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// bus & mmu
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wire [31:0] mar; // memory address register
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wire mar_we; // mar write enable
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wire ma_src; // memory address source selector
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wire [2:0] mmu_fnc; // mmu function
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wire [31:0] virt_addr; // virtual address
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wire [31:0] phys_addr; // physical address
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wire [31:0] mdor; // memory data out register
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wire mdor_we; // mdor write enable
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wire [31:0] mdir; // memory data in register
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wire mdir_we; // mdir write enable
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wire mdir_sx; // mdir sign-extend
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// instruction register & decoder
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wire ir_we; // ir write enable
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wire [5:0] opcode; // opcode part of ir
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wire [4:0] reg1; // register 1 part of ir
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wire [4:0] reg2; // register 2 part of ir
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wire [4:0] reg3; // register 3 part of ir
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wire [31:0] sx16; // sign-extended 16-bit immediate
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wire [31:0] zx16; // zero-extended 16-bit immediate
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wire [31:0] hi16; // high 16-bit immediate
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wire [31:0] sx16s2; // sign-extended 16-bit immediate << 2
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wire [31:0] sx26s2; // sign-extended 26-bit immediate << 2
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// register file
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wire [4:0] reg_a1; // register address 1
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wire [31:0] reg_do1; // register data out 1
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wire [1:0] reg_src2; // register source 2 selector
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wire [4:0] reg_a2; // register address 2
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wire [31:0] reg_do2; // register data out 2
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wire reg_we2; // register write enable 2
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wire reg_we2_prot; // register write enable 2,
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// protected against writes with a2 = 0
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wire [2:0] reg_di2_src; // register data in 2 source selector
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wire [31:0] reg_di2; // register data in 2
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// alu, shift, and muldiv units
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wire alu_src1; // alu source 1 selector
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wire [31:0] alu_op1; // alu operand 1
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wire [2:0] alu_src2; // alu source 2 selector
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wire [31:0] alu_op2; // alu operand 2
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wire [2:0] alu_fnc; // alu function
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wire [31:0] alu_res; // alu result
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wire alu_equ; // alu operand 1 = operand 2
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wire alu_ult; // alu operand 1 < operand 2 (unsigned)
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wire alu_slt; // alu operand 1 < operand 2 (signed)
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wire [1:0] shift_fnc; // shift function
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wire [31:0] shift_res; // shift result
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wire [2:0] muldiv_fnc; // muldiv function
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wire muldiv_start; // muldiv should start
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wire muldiv_done; // muldiv has finished
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wire muldiv_error; // muldiv detected division by zero
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wire [31:0] muldiv_res; // muldiv result
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// special registers
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wire [2:0] sreg_num; // special register number
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wire sreg_we; // special register write enable
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wire [31:0] sreg_di; // special register data in
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wire [31:0] sreg_do; // special register data out
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wire [31:0] psw; // special register 0 (psw) contents
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wire psw_we; // psw write enable
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wire [31:0] psw_new; // new psw contents
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wire [31:0] tlb_index; // special register 1 (tlb index) contents
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wire tlb_index_we; // tlb index write enable
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wire [31:0] tlb_index_new; // new tlb index contents
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wire [31:0] tlb_entry_hi; // special register 2 (tlb entry hi) contents
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wire tlb_entry_hi_we; // tlb entry hi write enable
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wire [31:0] tlb_entry_hi_new; // new tlb entry hi contents
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wire [31:0] tlb_entry_lo; // special register 3 (tlb entry lo) contents
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wire tlb_entry_lo_we; // tlb entry lo write enable
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wire [31:0] tlb_entry_lo_new; // new tlb entry lo contents
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wire [31:0] mmu_bad_addr; // special register 4 (mmu bad addr) contents
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wire mmu_bad_addr_we; // mmu bad addr write enable
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wire [31:0] mmu_bad_addr_new; // new mmu bad addr contents
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wire [31:0] mmu_bad_accs; // special register 5 (mmu bad accs) contents
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wire mmu_bad_accs_we; // mmu bad accs write enable
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wire [31:0] mmu_bad_accs_new; // new mmu bad accs contents
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// mmu & tlb
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wire tlb_kmissed; // page not found in tlb, MSB of addr is 1
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wire tlb_umissed; // page not found in tlb, MSB of addr is 0
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wire tlb_invalid; // tlb entry is invalid
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wire tlb_wrtprot; // frame is write-protected
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//------------------------------------------------------------
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// program counter
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assign pc_next = (pc_src == 3'b000) ? alu_res :
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(pc_src == 3'b001) ? 32'hE0000000 :
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(pc_src == 3'b010) ? 32'hE0000004 :
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(pc_src == 3'b011) ? 32'hC0000004 :
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(pc_src == 3'b100) ? 32'hE0000008 :
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(pc_src == 3'b101) ? 32'hC0000008 :
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32'hxxxxxxxx;
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pc pc_1(clk, pc_we, pc_next, pc);
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// bus & mmu
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mar mar_1(clk, mar_we, alu_res, mar);
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assign virt_addr = (ma_src == 0) ? pc : mar;
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mmu mmu_1(clk, rst, mmu_fnc, virt_addr, phys_addr,
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tlb_index, tlb_index_new,
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tlb_entry_hi, tlb_entry_hi_new,
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tlb_entry_lo, tlb_entry_lo_new,
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tlb_kmissed, tlb_umissed,
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tlb_invalid, tlb_wrtprot);
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assign bus_addr = phys_addr;
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mdor mdor_1(clk, mdor_we, reg_do2, mdor);
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assign bus_dout = mdor;
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mdir mdir_1(clk, mdir_we, bus_din, bus_size, mdir_sx, mdir);
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// instruction register & decoder
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ir ir_1(clk,
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ir_we, bus_din,
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opcode, reg1, reg2, reg3,
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sx16, zx16, hi16, sx16s2, sx26s2);
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// register file
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assign reg_a1 = reg1;
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assign reg_a2 = (reg_src2 == 2'b00) ? reg2 :
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(reg_src2 == 2'b01) ? reg3 :
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(reg_src2 == 2'b10) ? 5'b11111 :
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(reg_src2 == 2'b11) ? 5'b11110 :
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5'bxxxxx;
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assign reg_we2_prot = reg_we2 & (| reg_a2[4:0]);
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assign reg_di2 = (reg_di2_src == 3'b000) ? alu_res :
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(reg_di2_src == 3'b001) ? shift_res :
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(reg_di2_src == 3'b010) ? muldiv_res :
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(reg_di2_src == 3'b011) ? mdir :
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(reg_di2_src == 3'b100) ? sreg_do :
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32'hxxxxxxxx;
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regs regs_1(clk,
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reg_a1, reg_do1,
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reg_a2, reg_do2, reg_we2_prot, reg_di2);
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// alu, shift, and muldiv units
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assign alu_op1 = (alu_src1 == 0) ? pc : reg_do1;
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assign alu_op2 = (alu_src2 == 3'b000) ? 32'h00000004 :
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(alu_src2 == 3'b001) ? reg_do2 :
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(alu_src2 == 3'b010) ? sx16 :
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(alu_src2 == 3'b011) ? zx16 :
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(alu_src2 == 3'b100) ? hi16 :
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(alu_src2 == 3'b101) ? sx16s2 :
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(alu_src2 == 3'b110) ? sx26s2 :
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32'hxxxxxxxx;
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alu alu_1(alu_op1, alu_op2, alu_fnc,
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alu_res, alu_equ, alu_ult, alu_slt);
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shift shift_1(clk, alu_op1, alu_op2[4:0], shift_fnc, shift_res);
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muldiv muldiv_1(clk, alu_op1, alu_op2, muldiv_fnc, muldiv_start,
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muldiv_done, muldiv_error, muldiv_res);
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// special registers
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assign sreg_num = zx16[2:0];
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assign sreg_di = reg_do2;
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sregs sregs_1(clk, rst,
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sreg_num, sreg_we, sreg_di, sreg_do,
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psw, psw_we, psw_new,
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tlb_index, tlb_index_we, tlb_index_new,
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tlb_entry_hi, tlb_entry_hi_we, tlb_entry_hi_new,
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tlb_entry_lo, tlb_entry_lo_we, tlb_entry_lo_new,
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mmu_bad_addr, mmu_bad_addr_we, mmu_bad_addr_new,
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mmu_bad_accs, mmu_bad_accs_we, mmu_bad_accs_new);
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assign mmu_bad_addr_new = virt_addr;
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assign mmu_bad_accs_we = mmu_bad_addr_we;
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assign mmu_bad_accs_new = { 29'b0, bus_we, bus_size[1:0] };
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// ctrl
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ctrl ctrl_1(clk, rst,
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opcode, alu_equ, alu_ult, alu_slt,
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bus_ack, bus_stb, bus_we, bus_size,
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pc_src, pc_we,
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mar_we, ma_src, mmu_fnc,
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mdor_we, mdir_we, mdir_sx, ir_we,
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reg_src2, reg_di2_src, reg_we2,
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alu_src1, alu_src2, alu_fnc, shift_fnc,
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muldiv_fnc, muldiv_start,
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muldiv_done, muldiv_error,
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sreg_we, bus_irq, psw, psw_we, psw_new,
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virt_addr[31], virt_addr[1], virt_addr[0],
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tlb_kmissed, tlb_umissed,
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tlb_invalid, tlb_wrtprot,
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tlb_index_we, tlb_entry_hi_we,
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tlb_entry_lo_we, mmu_bad_addr_we);
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endmodule
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//--------------------------------------------------------------
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// ctrl -- the finite state machine within the CPU
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//--------------------------------------------------------------
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module ctrl(clk, rst,
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opcode, alu_equ, alu_ult, alu_slt,
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bus_ack, bus_stb, bus_we, bus_size,
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pc_src, pc_we,
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mar_we, ma_src, mmu_fnc,
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mdor_we, mdir_we, mdir_sx, ir_we,
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reg_src2, reg_di2_src, reg_we2,
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alu_src1, alu_src2, alu_fnc, shift_fnc,
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muldiv_fnc, muldiv_start,
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muldiv_done, muldiv_error,
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sreg_we, bus_irq, psw, psw_we, psw_new,
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va_31, va_1, va_0,
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tlb_kmissed, tlb_umissed,
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tlb_invalid, tlb_wrtprot,
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tlb_index_we, tlb_entry_hi_we,
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tlb_entry_lo_we, mmu_bad_addr_we);
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| 238 |
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input clk;
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| 239 |
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input rst;
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| 240 |
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input [5:0] opcode;
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| 241 |
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input alu_equ;
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| 242 |
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input alu_ult;
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| 243 |
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input alu_slt;
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| 244 |
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input bus_ack;
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| 245 |
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output reg bus_stb;
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| 246 |
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output reg bus_we;
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| 247 |
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output reg [1:0] bus_size;
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| 248 |
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output reg [2:0] pc_src;
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| 249 |
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output reg pc_we;
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| 250 |
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output reg mar_we;
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| 251 |
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output reg ma_src;
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| 252 |
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output reg [2:0] mmu_fnc;
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| 253 |
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output reg mdor_we;
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| 254 |
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output reg mdir_we;
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| 255 |
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output reg mdir_sx;
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| 256 |
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output reg ir_we;
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| 257 |
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output reg [1:0] reg_src2;
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| 258 |
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output reg [2:0] reg_di2_src;
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| 259 |
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output reg reg_we2;
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| 260 |
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output reg alu_src1;
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| 261 |
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output reg [2:0] alu_src2;
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| 262 |
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output reg [2:0] alu_fnc;
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| 263 |
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output reg [1:0] shift_fnc;
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| 264 |
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output reg [2:0] muldiv_fnc;
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| 265 |
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output reg muldiv_start;
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| 266 |
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input muldiv_done;
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| 267 |
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input muldiv_error;
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| 268 |
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output reg sreg_we;
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input [15:0] bus_irq;
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input [31:0] psw;
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output reg psw_we;
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output reg [31:0] psw_new;
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| 273 |
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input va_31, va_1, va_0;
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| 274 |
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input tlb_kmissed;
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| 275 |
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input tlb_umissed;
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input tlb_invalid;
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input tlb_wrtprot;
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| 278 |
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output reg tlb_index_we;
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output reg tlb_entry_hi_we;
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output reg tlb_entry_lo_we;
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| 281 |
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output reg mmu_bad_addr_we;
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| 283 |
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wire type_rrr; // instr type is RRR
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wire type_rrs; // instr type is RRS
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wire type_rrh; // instr type is RRH
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| 286 |
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wire type_rhh; // instr type is RHH
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wire type_rrb; // instr type is RRB
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wire type_j; // instr type is J
|
| 289 |
|
|
wire type_jr; // instr type is JR
|
| 290 |
|
|
wire type_link; // instr saves PC+4 in $31
|
| 291 |
|
|
wire type_ld; // instr loads data
|
| 292 |
|
|
wire type_st; // instr stores data
|
| 293 |
|
|
wire type_ldst; // instr loads or stores data
|
| 294 |
|
|
wire [1:0] ldst_size; // load/store transfer size
|
| 295 |
|
|
wire type_shift; // instr uses the shift unit
|
| 296 |
|
|
wire type_muldiv; // instr uses the muldiv unit
|
| 297 |
|
|
wire type_fast; // instr is not shift or muldiv
|
| 298 |
|
|
wire type_mvfs; // instr is mvfs
|
| 299 |
|
|
wire type_mvts; // instr is mvts
|
| 300 |
|
|
wire type_rfx; // instr is rfx
|
| 301 |
|
|
wire type_trap; // instr is trap
|
| 302 |
|
|
wire type_tb; // instr is a TLB instr
|
| 303 |
|
|
reg [4:0] state; // cpu internal state
|
| 304 |
|
|
// 0: reset
|
| 305 |
|
|
// 1: fetch instr (addr xlat)
|
| 306 |
|
|
// 2: decode instr
|
| 307 |
|
|
// increment pc by 4
|
| 308 |
|
|
// possibly store pc+4 in $31
|
| 309 |
|
|
// 3: execute RRR-type instr
|
| 310 |
|
|
// 4: execute RRS-type instr
|
| 311 |
|
|
// 5: execute RRH-type instr
|
| 312 |
|
|
// 6: execute RHH-type instr
|
| 313 |
|
|
// 7: execute RRB-type instr (1)
|
| 314 |
|
|
// 8: execute RRB-type instr (2)
|
| 315 |
|
|
// 9: execute J-type instr
|
| 316 |
|
|
// 10: execute JR-type instr
|
| 317 |
|
|
// 11: execute LDST-type instr (1)
|
| 318 |
|
|
// 12: execute LD-type instr (addr xlat)
|
| 319 |
|
|
// 13: execute LD-type instr (3)
|
| 320 |
|
|
// 14: execute ST-type instr (addr xlat)
|
| 321 |
|
|
// 15: interrupt
|
| 322 |
|
|
// 16: extra state for RRR shift instr
|
| 323 |
|
|
// 17: extra state for RRH shift instr
|
| 324 |
|
|
// 18: extra state for RRR muldiv instr
|
| 325 |
|
|
// 19: extra state for RRS muldiv instr
|
| 326 |
|
|
// 20: extra state for RRH muldiv instr
|
| 327 |
|
|
// 21: execute mvfs instr
|
| 328 |
|
|
// 22: execute mvts instr
|
| 329 |
|
|
// 23: execute rfx instr
|
| 330 |
|
|
// 24: irq_trigger check for mvts and rfx
|
| 331 |
|
|
// 25: exception (locus is PC-4)
|
| 332 |
|
|
// 26: exception (locus is PC)
|
| 333 |
|
|
// 27: execute TLB instr
|
| 334 |
|
|
// 28: fetch instr (bus cycle)
|
| 335 |
|
|
// 29: execute LD-type instr (bus cycle)
|
| 336 |
|
|
// 30: execute ST-type instr (bus cycle)
|
| 337 |
|
|
// all other: unused
|
| 338 |
|
|
reg branch; // take the branch iff true
|
| 339 |
|
|
wire [15:0] irq_pending; // the vector of pending unmasked irqs
|
| 340 |
|
|
wire irq_trigger; // true iff any pending irq is present
|
| 341 |
|
|
// and interrupts are globally enabled
|
| 342 |
|
|
reg [3:0] irq_priority; // highest priority of pending interrupts
|
| 343 |
|
|
reg [3:0] exc_priority; // exception, when entering state 25 or 26
|
| 344 |
|
|
reg [7:0] bus_count; // counter to detect bus timeout
|
| 345 |
|
|
wire bus_timeout; // bus timeout detected
|
| 346 |
|
|
wire exc_prv_addr; // privileged address exception detected
|
| 347 |
|
|
wire exc_ill_addr; // illegal address exception detected
|
| 348 |
|
|
wire exc_tlb_but_wrtprot; // any tlb exception but write protection
|
| 349 |
|
|
wire exc_tlb_any; // any tlb exception
|
| 350 |
|
|
|
| 351 |
|
|
//------------------------------------------------------------
|
| 352 |
|
|
|
| 353 |
|
|
// decode instr type
|
| 354 |
|
|
assign type_rrr = ((opcode == 6'h00) ||
|
| 355 |
|
|
(opcode == 6'h02) ||
|
| 356 |
|
|
(opcode == 6'h04) ||
|
| 357 |
|
|
(opcode == 6'h06) ||
|
| 358 |
|
|
(opcode == 6'h08) ||
|
| 359 |
|
|
(opcode == 6'h0A) ||
|
| 360 |
|
|
(opcode == 6'h0C) ||
|
| 361 |
|
|
(opcode == 6'h0E) ||
|
| 362 |
|
|
(opcode == 6'h10) ||
|
| 363 |
|
|
(opcode == 6'h12) ||
|
| 364 |
|
|
(opcode == 6'h14) ||
|
| 365 |
|
|
(opcode == 6'h16) ||
|
| 366 |
|
|
(opcode == 6'h18) ||
|
| 367 |
|
|
(opcode == 6'h1A) ||
|
| 368 |
|
|
(opcode == 6'h1C)) ? 1 : 0;
|
| 369 |
|
|
assign type_rrs = ((opcode == 6'h01) ||
|
| 370 |
|
|
(opcode == 6'h03) ||
|
| 371 |
|
|
(opcode == 6'h05) ||
|
| 372 |
|
|
(opcode == 6'h09) ||
|
| 373 |
|
|
(opcode == 6'h0D)) ? 1 : 0;
|
| 374 |
|
|
assign type_rrh = ((opcode == 6'h07) ||
|
| 375 |
|
|
(opcode == 6'h0B) ||
|
| 376 |
|
|
(opcode == 6'h0F) ||
|
| 377 |
|
|
(opcode == 6'h11) ||
|
| 378 |
|
|
(opcode == 6'h13) ||
|
| 379 |
|
|
(opcode == 6'h15) ||
|
| 380 |
|
|
(opcode == 6'h17) ||
|
| 381 |
|
|
(opcode == 6'h19) ||
|
| 382 |
|
|
(opcode == 6'h1B) ||
|
| 383 |
|
|
(opcode == 6'h1D)) ? 1 : 0;
|
| 384 |
|
|
assign type_rhh = (opcode == 6'h1F) ? 1 : 0;
|
| 385 |
|
|
assign type_rrb = ((opcode == 6'h20) ||
|
| 386 |
|
|
(opcode == 6'h21) ||
|
| 387 |
|
|
(opcode == 6'h22) ||
|
| 388 |
|
|
(opcode == 6'h23) ||
|
| 389 |
|
|
(opcode == 6'h24) ||
|
| 390 |
|
|
(opcode == 6'h25) ||
|
| 391 |
|
|
(opcode == 6'h26) ||
|
| 392 |
|
|
(opcode == 6'h27) ||
|
| 393 |
|
|
(opcode == 6'h28) ||
|
| 394 |
|
|
(opcode == 6'h29)) ? 1 : 0;
|
| 395 |
|
|
assign type_j = ((opcode == 6'h2A) ||
|
| 396 |
|
|
(opcode == 6'h2C)) ? 1 : 0;
|
| 397 |
|
|
assign type_jr = ((opcode == 6'h2B) ||
|
| 398 |
|
|
(opcode == 6'h2D)) ? 1 : 0;
|
| 399 |
|
|
assign type_link = ((opcode == 6'h2C) ||
|
| 400 |
|
|
(opcode == 6'h2D)) ? 1 : 0;
|
| 401 |
|
|
assign type_ld = ((opcode == 6'h30) ||
|
| 402 |
|
|
(opcode == 6'h31) ||
|
| 403 |
|
|
(opcode == 6'h32) ||
|
| 404 |
|
|
(opcode == 6'h33) ||
|
| 405 |
|
|
(opcode == 6'h34)) ? 1 : 0;
|
| 406 |
|
|
assign type_st = ((opcode == 6'h35) ||
|
| 407 |
|
|
(opcode == 6'h36) ||
|
| 408 |
|
|
(opcode == 6'h37)) ? 1 : 0;
|
| 409 |
|
|
assign type_ldst = type_ld | type_st;
|
| 410 |
|
|
assign ldst_size = ((opcode == 6'h30) ||
|
| 411 |
|
|
(opcode == 6'h35)) ? 2'b10 :
|
| 412 |
|
|
((opcode == 6'h31) ||
|
| 413 |
|
|
(opcode == 6'h32) ||
|
| 414 |
|
|
(opcode == 6'h36)) ? 2'b01 :
|
| 415 |
|
|
((opcode == 6'h33) ||
|
| 416 |
|
|
(opcode == 6'h34) ||
|
| 417 |
|
|
(opcode == 6'h37)) ? 2'b00 :
|
| 418 |
|
|
2'bxx;
|
| 419 |
|
|
assign type_shift = ((opcode == 6'h18) ||
|
| 420 |
|
|
(opcode == 6'h19) ||
|
| 421 |
|
|
(opcode == 6'h1A) ||
|
| 422 |
|
|
(opcode == 6'h1B) ||
|
| 423 |
|
|
(opcode == 6'h1C) ||
|
| 424 |
|
|
(opcode == 6'h1D)) ? 1 : 0;
|
| 425 |
|
|
assign type_muldiv = ((opcode == 6'h04) ||
|
| 426 |
|
|
(opcode == 6'h05) ||
|
| 427 |
|
|
(opcode == 6'h06) ||
|
| 428 |
|
|
(opcode == 6'h07) ||
|
| 429 |
|
|
(opcode == 6'h08) ||
|
| 430 |
|
|
(opcode == 6'h09) ||
|
| 431 |
|
|
(opcode == 6'h0A) ||
|
| 432 |
|
|
(opcode == 6'h0B) ||
|
| 433 |
|
|
(opcode == 6'h0C) ||
|
| 434 |
|
|
(opcode == 6'h0D) ||
|
| 435 |
|
|
(opcode == 6'h0E) ||
|
| 436 |
|
|
(opcode == 6'h0F)) ? 1 : 0;
|
| 437 |
|
|
assign type_fast = ~(type_shift | type_muldiv);
|
| 438 |
|
|
assign type_mvfs = (opcode == 6'h38) ? 1 : 0;
|
| 439 |
|
|
assign type_mvts = (opcode == 6'h39) ? 1 : 0;
|
| 440 |
|
|
assign type_rfx = (opcode == 6'h2F) ? 1 : 0;
|
| 441 |
|
|
assign type_trap = (opcode == 6'h2E) ? 1 : 0;
|
| 442 |
|
|
assign type_tb = ((opcode == 6'h3A) ||
|
| 443 |
|
|
(opcode == 6'h3B) ||
|
| 444 |
|
|
(opcode == 6'h3C) ||
|
| 445 |
|
|
(opcode == 6'h3D)) ? 1 : 0;
|
| 446 |
|
|
|
| 447 |
|
|
// state machine
|
| 448 |
|
|
always @(posedge clk) begin
|
| 449 |
|
|
if (rst == 1) begin
|
| 450 |
|
|
state <= 0;
|
| 451 |
|
|
end else begin
|
| 452 |
|
|
case (state)
|
| 453 |
|
|
5'd0: // reset
|
| 454 |
|
|
begin
|
| 455 |
|
|
state <= 5'd1;
|
| 456 |
|
|
end
|
| 457 |
|
|
5'd1: // fetch instr (addr xlat)
|
| 458 |
|
|
begin
|
| 459 |
|
|
if (exc_prv_addr) begin
|
| 460 |
|
|
state <= 26;
|
| 461 |
|
|
exc_priority <= 4'd9;
|
| 462 |
|
|
end else
|
| 463 |
|
|
if (exc_ill_addr) begin
|
| 464 |
|
|
state <= 26;
|
| 465 |
|
|
exc_priority <= 4'd8;
|
| 466 |
|
|
end else begin
|
| 467 |
|
|
state <= 5'd28;
|
| 468 |
|
|
end
|
| 469 |
|
|
end
|
| 470 |
|
|
5'd2: // decode instr
|
| 471 |
|
|
// increment pc by 4
|
| 472 |
|
|
// possibly store pc+4 in $31
|
| 473 |
|
|
begin
|
| 474 |
|
|
if (type_rrr) begin
|
| 475 |
|
|
// RRR-type instruction
|
| 476 |
|
|
state <= 5'd3;
|
| 477 |
|
|
end else
|
| 478 |
|
|
if (type_rrs) begin
|
| 479 |
|
|
// RRS-type instruction
|
| 480 |
|
|
state <= 5'd4;
|
| 481 |
|
|
end else
|
| 482 |
|
|
if (type_rrh) begin
|
| 483 |
|
|
// RRH-type instruction
|
| 484 |
|
|
state <= 5'd5;
|
| 485 |
|
|
end else
|
| 486 |
|
|
if (type_rhh) begin
|
| 487 |
|
|
// RHH-type instruction
|
| 488 |
|
|
state <= 5'd6;
|
| 489 |
|
|
end else
|
| 490 |
|
|
if (type_rrb) begin
|
| 491 |
|
|
// RRB-type instr
|
| 492 |
|
|
state <= 5'd7;
|
| 493 |
|
|
end else
|
| 494 |
|
|
if (type_j) begin
|
| 495 |
|
|
// J-type instr
|
| 496 |
|
|
state <= 5'd9;
|
| 497 |
|
|
end else
|
| 498 |
|
|
if (type_jr) begin
|
| 499 |
|
|
// JR-type instr
|
| 500 |
|
|
state <= 5'd10;
|
| 501 |
|
|
end else
|
| 502 |
|
|
if (type_ldst) begin
|
| 503 |
|
|
// LDST-type instr
|
| 504 |
|
|
state <= 5'd11;
|
| 505 |
|
|
end else
|
| 506 |
|
|
if (type_mvfs) begin
|
| 507 |
|
|
// mvfs instr
|
| 508 |
|
|
state <= 5'd21;
|
| 509 |
|
|
end else
|
| 510 |
|
|
if (type_mvts) begin
|
| 511 |
|
|
// mvts instr
|
| 512 |
|
|
if (psw[26] == 1) begin
|
| 513 |
|
|
state <= 5'd25;
|
| 514 |
|
|
exc_priority <= 4'd2;
|
| 515 |
|
|
end else begin
|
| 516 |
|
|
state <= 5'd22;
|
| 517 |
|
|
end
|
| 518 |
|
|
end else
|
| 519 |
|
|
if (type_rfx) begin
|
| 520 |
|
|
// rfx instr
|
| 521 |
|
|
if (psw[26] == 1) begin
|
| 522 |
|
|
state <= 5'd25;
|
| 523 |
|
|
exc_priority <= 4'd2;
|
| 524 |
|
|
end else begin
|
| 525 |
|
|
state <= 5'd23;
|
| 526 |
|
|
end
|
| 527 |
|
|
end else
|
| 528 |
|
|
if (type_trap) begin
|
| 529 |
|
|
// trap instr
|
| 530 |
|
|
state <= 5'd25;
|
| 531 |
|
|
exc_priority <= 4'd4;
|
| 532 |
|
|
end else
|
| 533 |
|
|
if (type_tb) begin
|
| 534 |
|
|
// TLB instr
|
| 535 |
|
|
if (psw[26] == 1) begin
|
| 536 |
|
|
state <= 5'd25;
|
| 537 |
|
|
exc_priority <= 4'd2;
|
| 538 |
|
|
end else begin
|
| 539 |
|
|
state <= 5'd27;
|
| 540 |
|
|
end
|
| 541 |
|
|
end else begin
|
| 542 |
|
|
// illegal instruction
|
| 543 |
|
|
state <= 5'd25;
|
| 544 |
|
|
exc_priority <= 4'd1;
|
| 545 |
|
|
end
|
| 546 |
|
|
end
|
| 547 |
|
|
5'd3: // execute RRR-type instr
|
| 548 |
|
|
begin
|
| 549 |
|
|
if (type_muldiv) begin
|
| 550 |
|
|
state <= 5'd18;
|
| 551 |
|
|
end else
|
| 552 |
|
|
if (type_shift) begin
|
| 553 |
|
|
state <= 5'd16;
|
| 554 |
|
|
end else begin
|
| 555 |
|
|
if (irq_trigger) begin
|
| 556 |
|
|
state <= 5'd15;
|
| 557 |
|
|
end else begin
|
| 558 |
|
|
state <= 5'd1;
|
| 559 |
|
|
end
|
| 560 |
|
|
end
|
| 561 |
|
|
end
|
| 562 |
|
|
5'd4: // execute RRS-type instr
|
| 563 |
|
|
begin
|
| 564 |
|
|
if (type_muldiv) begin
|
| 565 |
|
|
state <= 5'd19;
|
| 566 |
|
|
end else begin
|
| 567 |
|
|
if (irq_trigger) begin
|
| 568 |
|
|
state <= 5'd15;
|
| 569 |
|
|
end else begin
|
| 570 |
|
|
state <= 5'd1;
|
| 571 |
|
|
end
|
| 572 |
|
|
end
|
| 573 |
|
|
end
|
| 574 |
|
|
5'd5: // execute RRH-type instr
|
| 575 |
|
|
begin
|
| 576 |
|
|
if (type_muldiv) begin
|
| 577 |
|
|
state <= 5'd20;
|
| 578 |
|
|
end else
|
| 579 |
|
|
if (type_shift) begin
|
| 580 |
|
|
state <= 5'd17;
|
| 581 |
|
|
end else begin
|
| 582 |
|
|
if (irq_trigger) begin
|
| 583 |
|
|
state <= 5'd15;
|
| 584 |
|
|
end else begin
|
| 585 |
|
|
state <= 5'd1;
|
| 586 |
|
|
end
|
| 587 |
|
|
end
|
| 588 |
|
|
end
|
| 589 |
|
|
5'd6: // execute RHH-type instr
|
| 590 |
|
|
begin
|
| 591 |
|
|
if (irq_trigger) begin
|
| 592 |
|
|
state <= 5'd15;
|
| 593 |
|
|
end else begin
|
| 594 |
|
|
state <= 5'd1;
|
| 595 |
|
|
end
|
| 596 |
|
|
end
|
| 597 |
|
|
5'd7: // execute RRB-type instr (1)
|
| 598 |
|
|
begin
|
| 599 |
|
|
if (branch) begin
|
| 600 |
|
|
state <= 5'd8;
|
| 601 |
|
|
end else begin
|
| 602 |
|
|
if (irq_trigger) begin
|
| 603 |
|
|
state <= 5'd15;
|
| 604 |
|
|
end else begin
|
| 605 |
|
|
state <= 5'd1;
|
| 606 |
|
|
end
|
| 607 |
|
|
end
|
| 608 |
|
|
end
|
| 609 |
|
|
5'd8: // execute RRB-type instr (2)
|
| 610 |
|
|
begin
|
| 611 |
|
|
if (irq_trigger) begin
|
| 612 |
|
|
state <= 5'd15;
|
| 613 |
|
|
end else begin
|
| 614 |
|
|
state <= 5'd1;
|
| 615 |
|
|
end
|
| 616 |
|
|
end
|
| 617 |
|
|
5'd9: // execute J-type instr
|
| 618 |
|
|
begin
|
| 619 |
|
|
if (irq_trigger) begin
|
| 620 |
|
|
state <= 5'd15;
|
| 621 |
|
|
end else begin
|
| 622 |
|
|
state <= 5'd1;
|
| 623 |
|
|
end
|
| 624 |
|
|
end
|
| 625 |
|
|
5'd10: // execute JR-type instr
|
| 626 |
|
|
begin
|
| 627 |
|
|
if (irq_trigger) begin
|
| 628 |
|
|
state <= 5'd15;
|
| 629 |
|
|
end else begin
|
| 630 |
|
|
state <= 5'd1;
|
| 631 |
|
|
end
|
| 632 |
|
|
end
|
| 633 |
|
|
5'd11: // execute LDST-type instr (1)
|
| 634 |
|
|
begin
|
| 635 |
|
|
if (type_ld) begin
|
| 636 |
|
|
state <= 5'd12;
|
| 637 |
|
|
end else begin
|
| 638 |
|
|
state <= 5'd14;
|
| 639 |
|
|
end
|
| 640 |
|
|
end
|
| 641 |
|
|
5'd12: // execute LD-type instr (addr xlat)
|
| 642 |
|
|
begin
|
| 643 |
|
|
if (exc_prv_addr) begin
|
| 644 |
|
|
state <= 25;
|
| 645 |
|
|
exc_priority <= 4'd9;
|
| 646 |
|
|
end else
|
| 647 |
|
|
if (exc_ill_addr) begin
|
| 648 |
|
|
state <= 25;
|
| 649 |
|
|
exc_priority <= 4'd8;
|
| 650 |
|
|
end else begin
|
| 651 |
|
|
state <= 5'd29;
|
| 652 |
|
|
end
|
| 653 |
|
|
end
|
| 654 |
|
|
5'd13: // execute LD-type instr (3)
|
| 655 |
|
|
begin
|
| 656 |
|
|
if (irq_trigger) begin
|
| 657 |
|
|
state <= 5'd15;
|
| 658 |
|
|
end else begin
|
| 659 |
|
|
state <= 5'd1;
|
| 660 |
|
|
end
|
| 661 |
|
|
end
|
| 662 |
|
|
5'd14: // execute ST-type instr (addr xlat)
|
| 663 |
|
|
begin
|
| 664 |
|
|
if (exc_prv_addr) begin
|
| 665 |
|
|
state <= 25;
|
| 666 |
|
|
exc_priority <= 4'd9;
|
| 667 |
|
|
end else
|
| 668 |
|
|
if (exc_ill_addr) begin
|
| 669 |
|
|
state <= 25;
|
| 670 |
|
|
exc_priority <= 4'd8;
|
| 671 |
|
|
end else begin
|
| 672 |
|
|
state <= 5'd30;
|
| 673 |
|
|
end
|
| 674 |
|
|
end
|
| 675 |
|
|
5'd15: // interrupt
|
| 676 |
|
|
begin
|
| 677 |
|
|
state <= 5'd1;
|
| 678 |
|
|
end
|
| 679 |
|
|
5'd16: // extra state for RRR shift instr
|
| 680 |
|
|
begin
|
| 681 |
|
|
if (irq_trigger) begin
|
| 682 |
|
|
state <= 5'd15;
|
| 683 |
|
|
end else begin
|
| 684 |
|
|
state <= 5'd1;
|
| 685 |
|
|
end
|
| 686 |
|
|
end
|
| 687 |
|
|
5'd17: // extra state for RRH shift instr
|
| 688 |
|
|
begin
|
| 689 |
|
|
if (irq_trigger) begin
|
| 690 |
|
|
state <= 5'd15;
|
| 691 |
|
|
end else begin
|
| 692 |
|
|
state <= 5'd1;
|
| 693 |
|
|
end
|
| 694 |
|
|
end
|
| 695 |
|
|
5'd18: // extra state for RRR muldiv instr
|
| 696 |
|
|
begin
|
| 697 |
|
|
if (muldiv_done) begin
|
| 698 |
|
|
if (muldiv_error) begin
|
| 699 |
|
|
state <= 5'd25;
|
| 700 |
|
|
exc_priority <= 4'd3;
|
| 701 |
|
|
end else
|
| 702 |
|
|
if (irq_trigger) begin
|
| 703 |
|
|
state <= 5'd15;
|
| 704 |
|
|
end else begin
|
| 705 |
|
|
state <= 5'd1;
|
| 706 |
|
|
end
|
| 707 |
|
|
end else begin
|
| 708 |
|
|
state <= 5'd18;
|
| 709 |
|
|
end
|
| 710 |
|
|
end
|
| 711 |
|
|
5'd19: // extra state for RRS muldiv instr
|
| 712 |
|
|
begin
|
| 713 |
|
|
if (muldiv_done) begin
|
| 714 |
|
|
if (muldiv_error) begin
|
| 715 |
|
|
state <= 5'd25;
|
| 716 |
|
|
exc_priority <= 4'd3;
|
| 717 |
|
|
end else
|
| 718 |
|
|
if (irq_trigger) begin
|
| 719 |
|
|
state <= 5'd15;
|
| 720 |
|
|
end else begin
|
| 721 |
|
|
state <= 5'd1;
|
| 722 |
|
|
end
|
| 723 |
|
|
end else begin
|
| 724 |
|
|
state <= 5'd19;
|
| 725 |
|
|
end
|
| 726 |
|
|
end
|
| 727 |
|
|
5'd20: // extra state for RRH muldiv instr
|
| 728 |
|
|
begin
|
| 729 |
|
|
if (muldiv_done) begin
|
| 730 |
|
|
if (muldiv_error) begin
|
| 731 |
|
|
state <= 5'd25;
|
| 732 |
|
|
exc_priority <= 4'd3;
|
| 733 |
|
|
end else
|
| 734 |
|
|
if (irq_trigger) begin
|
| 735 |
|
|
state <= 5'd15;
|
| 736 |
|
|
end else begin
|
| 737 |
|
|
state <= 5'd1;
|
| 738 |
|
|
end
|
| 739 |
|
|
end else begin
|
| 740 |
|
|
state <= 5'd20;
|
| 741 |
|
|
end
|
| 742 |
|
|
end
|
| 743 |
|
|
5'd21: // execute mvfs instr
|
| 744 |
|
|
begin
|
| 745 |
|
|
if (irq_trigger) begin
|
| 746 |
|
|
state <= 5'd15;
|
| 747 |
|
|
end else begin
|
| 748 |
|
|
state <= 5'd1;
|
| 749 |
|
|
end
|
| 750 |
|
|
end
|
| 751 |
|
|
5'd22: // execute mvts instr
|
| 752 |
|
|
begin
|
| 753 |
|
|
state <= 5'd24;
|
| 754 |
|
|
end
|
| 755 |
|
|
5'd23: // execute rfx instr
|
| 756 |
|
|
begin
|
| 757 |
|
|
state <= 5'd24;
|
| 758 |
|
|
end
|
| 759 |
|
|
5'd24: // irq_trigger check for mvts and rfx
|
| 760 |
|
|
begin
|
| 761 |
|
|
if (irq_trigger) begin
|
| 762 |
|
|
state <= 5'd15;
|
| 763 |
|
|
end else begin
|
| 764 |
|
|
state <= 5'd1;
|
| 765 |
|
|
end
|
| 766 |
|
|
end
|
| 767 |
|
|
5'd25: // exception (locus is PC-4)
|
| 768 |
|
|
begin
|
| 769 |
|
|
state <= 5'd1;
|
| 770 |
|
|
end
|
| 771 |
|
|
5'd26: // exception (locus is PC)
|
| 772 |
|
|
begin
|
| 773 |
|
|
state <= 5'd1;
|
| 774 |
|
|
end
|
| 775 |
|
|
5'd27: // execute TLB instr
|
| 776 |
|
|
begin
|
| 777 |
|
|
if (irq_trigger) begin
|
| 778 |
|
|
state <= 5'd15;
|
| 779 |
|
|
end else begin
|
| 780 |
|
|
state <= 5'd1;
|
| 781 |
|
|
end
|
| 782 |
|
|
end
|
| 783 |
|
|
5'd28: // fetch instr (bus cycle)
|
| 784 |
|
|
begin
|
| 785 |
|
|
if (tlb_kmissed == 1 || tlb_umissed == 1) begin
|
| 786 |
|
|
state <= 5'd26;
|
| 787 |
|
|
exc_priority <= 4'd5;
|
| 788 |
|
|
end else
|
| 789 |
|
|
if (tlb_invalid == 1) begin
|
| 790 |
|
|
state <= 5'd26;
|
| 791 |
|
|
exc_priority <= 4'd7;
|
| 792 |
|
|
end else
|
| 793 |
|
|
if (bus_ack == 0) begin
|
| 794 |
|
|
if (bus_timeout == 1) begin
|
| 795 |
|
|
state <= 5'd26;
|
| 796 |
|
|
exc_priority <= 4'd0;
|
| 797 |
|
|
end else begin
|
| 798 |
|
|
state <= 5'd28;
|
| 799 |
|
|
end
|
| 800 |
|
|
end else begin
|
| 801 |
|
|
state <= 5'd2;
|
| 802 |
|
|
end
|
| 803 |
|
|
end
|
| 804 |
|
|
5'd29: // execute LD-type instr (bus cycle)
|
| 805 |
|
|
begin
|
| 806 |
|
|
if (tlb_kmissed == 1 || tlb_umissed == 1) begin
|
| 807 |
|
|
state <= 5'd25;
|
| 808 |
|
|
exc_priority <= 4'd5;
|
| 809 |
|
|
end else
|
| 810 |
|
|
if (tlb_invalid == 1) begin
|
| 811 |
|
|
state <= 5'd25;
|
| 812 |
|
|
exc_priority <= 4'd7;
|
| 813 |
|
|
end else
|
| 814 |
|
|
if (bus_ack == 0) begin
|
| 815 |
|
|
if (bus_timeout == 1) begin
|
| 816 |
|
|
state <= 5'd25;
|
| 817 |
|
|
exc_priority <= 4'd0;
|
| 818 |
|
|
end else begin
|
| 819 |
|
|
state <= 5'd29;
|
| 820 |
|
|
end
|
| 821 |
|
|
end else begin
|
| 822 |
|
|
state <= 5'd13;
|
| 823 |
|
|
end
|
| 824 |
|
|
end
|
| 825 |
|
|
5'd30: // execute ST-type instr (bus cycle)
|
| 826 |
|
|
begin
|
| 827 |
|
|
if (tlb_kmissed == 1 || tlb_umissed == 1) begin
|
| 828 |
|
|
state <= 5'd25;
|
| 829 |
|
|
exc_priority <= 4'd5;
|
| 830 |
|
|
end else
|
| 831 |
|
|
if (tlb_invalid == 1) begin
|
| 832 |
|
|
state <= 5'd25;
|
| 833 |
|
|
exc_priority <= 4'd7;
|
| 834 |
|
|
end else
|
| 835 |
|
|
if (tlb_wrtprot == 1) begin
|
| 836 |
|
|
state <= 5'd25;
|
| 837 |
|
|
exc_priority <= 4'd6;
|
| 838 |
|
|
end else
|
| 839 |
|
|
if (bus_ack == 0) begin
|
| 840 |
|
|
if (bus_timeout == 1) begin
|
| 841 |
|
|
state <= 5'd25;
|
| 842 |
|
|
exc_priority <= 4'd0;
|
| 843 |
|
|
end else begin
|
| 844 |
|
|
state <= 5'd30;
|
| 845 |
|
|
end
|
| 846 |
|
|
end else begin
|
| 847 |
|
|
if (irq_trigger) begin
|
| 848 |
|
|
state <= 5'd15;
|
| 849 |
|
|
end else begin
|
| 850 |
|
|
state <= 5'd1;
|
| 851 |
|
|
end
|
| 852 |
|
|
end
|
| 853 |
|
|
end
|
| 854 |
|
|
default: // all other states: unused
|
| 855 |
|
|
begin
|
| 856 |
|
|
state <= 5'd0;
|
| 857 |
|
|
end
|
| 858 |
|
|
endcase
|
| 859 |
|
|
end
|
| 860 |
|
|
end
|
| 861 |
|
|
|
| 862 |
|
|
// bus timeout detector
|
| 863 |
|
|
assign bus_timeout = (bus_count == 8'h00) ? 1 : 0;
|
| 864 |
|
|
always @(posedge clk) begin
|
| 865 |
|
|
if (bus_stb == 1 && bus_ack == 0) begin
|
| 866 |
|
|
// bus is waiting
|
| 867 |
|
|
bus_count <= bus_count - 1;
|
| 868 |
|
|
end else begin
|
| 869 |
|
|
// bus is not waiting
|
| 870 |
|
|
bus_count <= 8'hFF;
|
| 871 |
|
|
end
|
| 872 |
|
|
end
|
| 873 |
|
|
|
| 874 |
|
|
// output logic
|
| 875 |
|
|
always @(*) begin
|
| 876 |
|
|
case (state)
|
| 877 |
|
|
5'd0: // reset
|
| 878 |
|
|
begin
|
| 879 |
|
|
pc_src = 3'b001;
|
| 880 |
|
|
pc_we = 1'b1;
|
| 881 |
|
|
mar_we = 1'b0;
|
| 882 |
|
|
ma_src = 1'bx;
|
| 883 |
|
|
mmu_fnc = 3'b000;
|
| 884 |
|
|
mdor_we = 1'b0;
|
| 885 |
|
|
bus_stb = 1'b0;
|
| 886 |
|
|
bus_we = 1'bx;
|
| 887 |
|
|
bus_size = 2'bxx;
|
| 888 |
|
|
mdir_we = 1'b0;
|
| 889 |
|
|
mdir_sx = 1'bx;
|
| 890 |
|
|
ir_we = 1'b0;
|
| 891 |
|
|
reg_src2 = 2'bxx;
|
| 892 |
|
|
reg_di2_src = 3'bxxx;
|
| 893 |
|
|
reg_we2 = 1'b0;
|
| 894 |
|
|
alu_src1 = 1'bx;
|
| 895 |
|
|
alu_src2 = 3'bxxx;
|
| 896 |
|
|
alu_fnc = 3'bxxx;
|
| 897 |
|
|
shift_fnc = 2'bxx;
|
| 898 |
|
|
muldiv_fnc = 3'bxxx;
|
| 899 |
|
|
muldiv_start = 1'b0;
|
| 900 |
|
|
sreg_we = 1'b0;
|
| 901 |
|
|
psw_we = 1'b0;
|
| 902 |
|
|
psw_new = 32'hxxxxxxxx;
|
| 903 |
|
|
tlb_index_we = 1'b0;
|
| 904 |
|
|
tlb_entry_hi_we = 1'b0;
|
| 905 |
|
|
tlb_entry_lo_we = 1'b0;
|
| 906 |
|
|
mmu_bad_addr_we = 1'b0;
|
| 907 |
|
|
end
|
| 908 |
|
|
5'd1: // fetch instr (addr xlat)
|
| 909 |
|
|
begin
|
| 910 |
|
|
pc_src = 3'bxxx;
|
| 911 |
|
|
pc_we = 1'b0;
|
| 912 |
|
|
mar_we = 1'b0;
|
| 913 |
|
|
ma_src = 1'b0;
|
| 914 |
|
|
mmu_fnc = (exc_prv_addr | exc_ill_addr) ? 3'b000 : 3'b001;
|
| 915 |
|
|
mdor_we = 1'b0;
|
| 916 |
|
|
bus_stb = 1'b0;
|
| 917 |
|
|
bus_we = 1'b0; // get bad_accs right in case of exc
|
| 918 |
|
|
bus_size = 2'b10; // enable illegal address detection
|
| 919 |
|
|
mdir_we = 1'b0;
|
| 920 |
|
|
mdir_sx = 1'bx;
|
| 921 |
|
|
ir_we = 1'b0;
|
| 922 |
|
|
reg_src2 = 2'bxx;
|
| 923 |
|
|
reg_di2_src = 3'bxxx;
|
| 924 |
|
|
reg_we2 = 1'b0;
|
| 925 |
|
|
alu_src1 = 1'bx;
|
| 926 |
|
|
alu_src2 = 3'bxxx;
|
| 927 |
|
|
alu_fnc = 3'bxxx;
|
| 928 |
|
|
shift_fnc = 2'bxx;
|
| 929 |
|
|
muldiv_fnc = 3'bxxx;
|
| 930 |
|
|
muldiv_start = 1'b0;
|
| 931 |
|
|
sreg_we = 1'b0;
|
| 932 |
|
|
psw_we = 1'b0;
|
| 933 |
|
|
psw_new = 32'hxxxxxxxx;
|
| 934 |
|
|
tlb_index_we = 1'b0;
|
| 935 |
|
|
tlb_entry_hi_we = 1'b0;
|
| 936 |
|
|
tlb_entry_lo_we = 1'b0;
|
| 937 |
|
|
mmu_bad_addr_we = exc_prv_addr | exc_ill_addr;
|
| 938 |
|
|
end
|
| 939 |
|
|
5'd2: // decode instr
|
| 940 |
|
|
// increment pc by 4
|
| 941 |
|
|
// possibly store pc+4 in $31
|
| 942 |
|
|
begin
|
| 943 |
|
|
pc_src = 3'b000;
|
| 944 |
|
|
pc_we = 1'b1;
|
| 945 |
|
|
mar_we = 1'b0;
|
| 946 |
|
|
ma_src = 1'bx;
|
| 947 |
|
|
mmu_fnc = 3'b000;
|
| 948 |
|
|
mdor_we = 1'b0;
|
| 949 |
|
|
bus_stb = 1'b0;
|
| 950 |
|
|
bus_we = 1'bx;
|
| 951 |
|
|
bus_size = 2'bxx;
|
| 952 |
|
|
mdir_we = 1'b0;
|
| 953 |
|
|
mdir_sx = 1'bx;
|
| 954 |
|
|
ir_we = 1'b0;
|
| 955 |
|
|
reg_src2 = (type_link == 1) ? 2'b10 :
|
| 956 |
|
|
(type_rfx == 1) ? 2'b11 :
|
| 957 |
|
|
2'b00;
|
| 958 |
|
|
reg_di2_src = (type_link == 1) ? 3'b000 : 3'bxxx;
|
| 959 |
|
|
reg_we2 = (type_link == 1) ? 1'b1 : 1'b0;
|
| 960 |
|
|
alu_src1 = 1'b0;
|
| 961 |
|
|
alu_src2 = 3'b000;
|
| 962 |
|
|
alu_fnc = 3'b000;
|
| 963 |
|
|
shift_fnc = 2'bxx;
|
| 964 |
|
|
muldiv_fnc = 3'bxxx;
|
| 965 |
|
|
muldiv_start = 1'b0;
|
| 966 |
|
|
sreg_we = 1'b0;
|
| 967 |
|
|
psw_we = 1'b0;
|
| 968 |
|
|
psw_new = 32'hxxxxxxxx;
|
| 969 |
|
|
tlb_index_we = 1'b0;
|
| 970 |
|
|
tlb_entry_hi_we = 1'b0;
|
| 971 |
|
|
tlb_entry_lo_we = 1'b0;
|
| 972 |
|
|
mmu_bad_addr_we = 1'b0;
|
| 973 |
|
|
end
|
| 974 |
|
|
5'd3: // execute RRR-type instr
|
| 975 |
|
|
begin
|
| 976 |
|
|
pc_src = 3'bxxx;
|
| 977 |
|
|
pc_we = 1'b0;
|
| 978 |
|
|
mar_we = 1'b0;
|
| 979 |
|
|
ma_src = 1'bx;
|
| 980 |
|
|
mmu_fnc = 3'b000;
|
| 981 |
|
|
mdor_we = 1'b0;
|
| 982 |
|
|
bus_stb = 1'b0;
|
| 983 |
|
|
bus_we = 1'bx;
|
| 984 |
|
|
bus_size = 2'bxx;
|
| 985 |
|
|
mdir_we = 1'b0;
|
| 986 |
|
|
mdir_sx = 1'bx;
|
| 987 |
|
|
ir_we = 1'b0;
|
| 988 |
|
|
reg_src2 = 2'b01;
|
| 989 |
|
|
reg_di2_src = 3'b000;
|
| 990 |
|
|
reg_we2 = type_fast;
|
| 991 |
|
|
alu_src1 = 1'b1;
|
| 992 |
|
|
alu_src2 = 3'b001;
|
| 993 |
|
|
alu_fnc = { opcode[4], opcode[2], opcode[1] };
|
| 994 |
|
|
shift_fnc = { opcode[2], opcode[1] };
|
| 995 |
|
|
muldiv_fnc = { opcode[3], opcode[2], opcode[1] };
|
| 996 |
|
|
muldiv_start = type_muldiv;
|
| 997 |
|
|
sreg_we = 1'b0;
|
| 998 |
|
|
psw_we = 1'b0;
|
| 999 |
|
|
psw_new = 32'hxxxxxxxx;
|
| 1000 |
|
|
tlb_index_we = 1'b0;
|
| 1001 |
|
|
tlb_entry_hi_we = 1'b0;
|
| 1002 |
|
|
tlb_entry_lo_we = 1'b0;
|
| 1003 |
|
|
mmu_bad_addr_we = 1'b0;
|
| 1004 |
|
|
end
|
| 1005 |
|
|
5'd4: // execute RRS-type instr
|
| 1006 |
|
|
begin
|
| 1007 |
|
|
pc_src = 3'bxxx;
|
| 1008 |
|
|
pc_we = 1'b0;
|
| 1009 |
|
|
mar_we = 1'b0;
|
| 1010 |
|
|
ma_src = 1'bx;
|
| 1011 |
|
|
mmu_fnc = 3'b000;
|
| 1012 |
|
|
mdor_we = 1'b0;
|
| 1013 |
|
|
bus_stb = 1'b0;
|
| 1014 |
|
|
bus_we = 1'bx;
|
| 1015 |
|
|
bus_size = 2'bxx;
|
| 1016 |
|
|
mdir_we = 1'b0;
|
| 1017 |
|
|
mdir_sx = 1'bx;
|
| 1018 |
|
|
ir_we = 1'b0;
|
| 1019 |
|
|
reg_src2 = 2'b00;
|
| 1020 |
|
|
reg_di2_src = 3'b000;
|
| 1021 |
|
|
reg_we2 = type_fast;
|
| 1022 |
|
|
alu_src1 = 1'b1;
|
| 1023 |
|
|
alu_src2 = 3'b010;
|
| 1024 |
|
|
alu_fnc = { opcode[4], opcode[2], opcode[1] };
|
| 1025 |
|
|
shift_fnc = 2'bxx;
|
| 1026 |
|
|
muldiv_fnc = { opcode[3], opcode[2], opcode[1] };
|
| 1027 |
|
|
muldiv_start = type_muldiv;
|
| 1028 |
|
|
sreg_we = 1'b0;
|
| 1029 |
|
|
psw_we = 1'b0;
|
| 1030 |
|
|
psw_new = 32'hxxxxxxxx;
|
| 1031 |
|
|
tlb_index_we = 1'b0;
|
| 1032 |
|
|
tlb_entry_hi_we = 1'b0;
|
| 1033 |
|
|
tlb_entry_lo_we = 1'b0;
|
| 1034 |
|
|
mmu_bad_addr_we = 1'b0;
|
| 1035 |
|
|
end
|
| 1036 |
|
|
5'd5: // execute RRH-type instr
|
| 1037 |
|
|
begin
|
| 1038 |
|
|
pc_src = 3'bxxx;
|
| 1039 |
|
|
pc_we = 1'b0;
|
| 1040 |
|
|
mar_we = 1'b0;
|
| 1041 |
|
|
ma_src = 1'bx;
|
| 1042 |
|
|
mmu_fnc = 3'b000;
|
| 1043 |
|
|
mdor_we = 1'b0;
|
| 1044 |
|
|
bus_stb = 1'b0;
|
| 1045 |
|
|
bus_we = 1'bx;
|
| 1046 |
|
|
bus_size = 2'bxx;
|
| 1047 |
|
|
mdir_we = 1'b0;
|
| 1048 |
|
|
mdir_sx = 1'bx;
|
| 1049 |
|
|
ir_we = 1'b0;
|
| 1050 |
|
|
reg_src2 = 2'b00;
|
| 1051 |
|
|
reg_di2_src = 3'b000;
|
| 1052 |
|
|
reg_we2 = type_fast;
|
| 1053 |
|
|
alu_src1 = 1'b1;
|
| 1054 |
|
|
alu_src2 = 3'b011;
|
| 1055 |
|
|
alu_fnc = { opcode[4], opcode[2], opcode[1] };
|
| 1056 |
|
|
shift_fnc = { opcode[2], opcode[1] };
|
| 1057 |
|
|
muldiv_fnc = { opcode[3], opcode[2], opcode[1] };
|
| 1058 |
|
|
muldiv_start = type_muldiv;
|
| 1059 |
|
|
sreg_we = 1'b0;
|
| 1060 |
|
|
psw_we = 1'b0;
|
| 1061 |
|
|
psw_new = 32'hxxxxxxxx;
|
| 1062 |
|
|
tlb_index_we = 1'b0;
|
| 1063 |
|
|
tlb_entry_hi_we = 1'b0;
|
| 1064 |
|
|
tlb_entry_lo_we = 1'b0;
|
| 1065 |
|
|
mmu_bad_addr_we = 1'b0;
|
| 1066 |
|
|
end
|
| 1067 |
|
|
5'd6: // execute RHH-type instr
|
| 1068 |
|
|
begin
|
| 1069 |
|
|
pc_src = 3'bxxx;
|
| 1070 |
|
|
pc_we = 1'b0;
|
| 1071 |
|
|
mar_we = 1'b0;
|
| 1072 |
|
|
ma_src = 1'bx;
|
| 1073 |
|
|
mmu_fnc = 3'b000;
|
| 1074 |
|
|
mdor_we = 1'b0;
|
| 1075 |
|
|
bus_stb = 1'b0;
|
| 1076 |
|
|
bus_we = 1'bx;
|
| 1077 |
|
|
bus_size = 2'bxx;
|
| 1078 |
|
|
mdir_we = 1'b0;
|
| 1079 |
|
|
mdir_sx = 1'bx;
|
| 1080 |
|
|
ir_we = 1'b0;
|
| 1081 |
|
|
reg_src2 = 2'b00;
|
| 1082 |
|
|
reg_di2_src = 3'b000;
|
| 1083 |
|
|
reg_we2 = 1'b1;
|
| 1084 |
|
|
alu_src1 = 1'bx;
|
| 1085 |
|
|
alu_src2 = 3'b100;
|
| 1086 |
|
|
alu_fnc = 3'b011;
|
| 1087 |
|
|
shift_fnc = 2'bxx;
|
| 1088 |
|
|
muldiv_fnc = 3'bxxx;
|
| 1089 |
|
|
muldiv_start = 1'b0;
|
| 1090 |
|
|
sreg_we = 1'b0;
|
| 1091 |
|
|
psw_we = 1'b0;
|
| 1092 |
|
|
psw_new = 32'hxxxxxxxx;
|
| 1093 |
|
|
tlb_index_we = 1'b0;
|
| 1094 |
|
|
tlb_entry_hi_we = 1'b0;
|
| 1095 |
|
|
tlb_entry_lo_we = 1'b0;
|
| 1096 |
|
|
mmu_bad_addr_we = 1'b0;
|
| 1097 |
|
|
end
|
| 1098 |
|
|
5'd7: // execute RRB-type instr (1)
|
| 1099 |
|
|
begin
|
| 1100 |
|
|
pc_src = 3'bxxx;
|
| 1101 |
|
|
pc_we = 1'b0;
|
| 1102 |
|
|
mar_we = 1'b0;
|
| 1103 |
|
|
ma_src = 1'bx;
|
| 1104 |
|
|
mmu_fnc = 3'b000;
|
| 1105 |
|
|
mdor_we = 1'b0;
|
| 1106 |
|
|
bus_stb = 1'b0;
|
| 1107 |
|
|
bus_we = 1'bx;
|
| 1108 |
|
|
bus_size = 2'bxx;
|
| 1109 |
|
|
mdir_we = 1'b0;
|
| 1110 |
|
|
mdir_sx = 1'bx;
|
| 1111 |
|
|
ir_we = 1'b0;
|
| 1112 |
|
|
reg_src2 = 2'bxx;
|
| 1113 |
|
|
reg_di2_src = 3'bxxx;
|
| 1114 |
|
|
reg_we2 = 1'b0;
|
| 1115 |
|
|
alu_src1 = 1'b1;
|
| 1116 |
|
|
alu_src2 = 3'b001;
|
| 1117 |
|
|
alu_fnc = 3'b001;
|
| 1118 |
|
|
shift_fnc = 2'bxx;
|
| 1119 |
|
|
muldiv_fnc = 3'bxxx;
|
| 1120 |
|
|
muldiv_start = 1'b0;
|
| 1121 |
|
|
sreg_we = 1'b0;
|
| 1122 |
|
|
psw_we = 1'b0;
|
| 1123 |
|
|
psw_new = 32'hxxxxxxxx;
|
| 1124 |
|
|
tlb_index_we = 1'b0;
|
| 1125 |
|
|
tlb_entry_hi_we = 1'b0;
|
| 1126 |
|
|
tlb_entry_lo_we = 1'b0;
|
| 1127 |
|
|
mmu_bad_addr_we = 1'b0;
|
| 1128 |
|
|
end
|
| 1129 |
|
|
5'd8: // execute RRB-type instr (2)
|
| 1130 |
|
|
begin
|
| 1131 |
|
|
pc_src = 3'b000;
|
| 1132 |
|
|
pc_we = 1'b1;
|
| 1133 |
|
|
mar_we = 1'b0;
|
| 1134 |
|
|
ma_src = 1'bx;
|
| 1135 |
|
|
mmu_fnc = 3'b000;
|
| 1136 |
|
|
mdor_we = 1'b0;
|
| 1137 |
|
|
bus_stb = 1'b0;
|
| 1138 |
|
|
bus_we = 1'bx;
|
| 1139 |
|
|
bus_size = 2'bxx;
|
| 1140 |
|
|
mdir_we = 1'b0;
|
| 1141 |
|
|
mdir_sx = 1'bx;
|
| 1142 |
|
|
ir_we = 1'b0;
|
| 1143 |
|
|
reg_src2 = 2'bxx;
|
| 1144 |
|
|
reg_di2_src = 3'bxxx;
|
| 1145 |
|
|
reg_we2 = 1'b0;
|
| 1146 |
|
|
alu_src1 = 1'b0;
|
| 1147 |
|
|
alu_src2 = 3'b101;
|
| 1148 |
|
|
alu_fnc = 3'b000;
|
| 1149 |
|
|
shift_fnc = 2'bxx;
|
| 1150 |
|
|
muldiv_fnc = 3'bxxx;
|
| 1151 |
|
|
muldiv_start = 1'b0;
|
| 1152 |
|
|
sreg_we = 1'b0;
|
| 1153 |
|
|
psw_we = 1'b0;
|
| 1154 |
|
|
psw_new = 32'hxxxxxxxx;
|
| 1155 |
|
|
tlb_index_we = 1'b0;
|
| 1156 |
|
|
tlb_entry_hi_we = 1'b0;
|
| 1157 |
|
|
tlb_entry_lo_we = 1'b0;
|
| 1158 |
|
|
mmu_bad_addr_we = 1'b0;
|
| 1159 |
|
|
end
|
| 1160 |
|
|
5'd9: // execute J-type instr
|
| 1161 |
|
|
begin
|
| 1162 |
|
|
pc_src = 3'b000;
|
| 1163 |
|
|
pc_we = 1'b1;
|
| 1164 |
|
|
mar_we = 1'b0;
|
| 1165 |
|
|
ma_src = 1'bx;
|
| 1166 |
|
|
mmu_fnc = 3'b000;
|
| 1167 |
|
|
mdor_we = 1'b0;
|
| 1168 |
|
|
bus_stb = 1'b0;
|
| 1169 |
|
|
bus_we = 1'bx;
|
| 1170 |
|
|
bus_size = 2'bxx;
|
| 1171 |
|
|
mdir_we = 1'b0;
|
| 1172 |
|
|
mdir_sx = 1'bx;
|
| 1173 |
|
|
ir_we = 1'b0;
|
| 1174 |
|
|
reg_src2 = 2'bxx;
|
| 1175 |
|
|
reg_di2_src = 3'bxxx;
|
| 1176 |
|
|
reg_we2 = 1'b0;
|
| 1177 |
|
|
alu_src1 = 1'b0;
|
| 1178 |
|
|
alu_src2 = 3'b110;
|
| 1179 |
|
|
alu_fnc = 3'b000;
|
| 1180 |
|
|
shift_fnc = 2'bxx;
|
| 1181 |
|
|
muldiv_fnc = 3'bxxx;
|
| 1182 |
|
|
muldiv_start = 1'b0;
|
| 1183 |
|
|
sreg_we = 1'b0;
|
| 1184 |
|
|
psw_we = 1'b0;
|
| 1185 |
|
|
psw_new = 32'hxxxxxxxx;
|
| 1186 |
|
|
tlb_index_we = 1'b0;
|
| 1187 |
|
|
tlb_entry_hi_we = 1'b0;
|
| 1188 |
|
|
tlb_entry_lo_we = 1'b0;
|
| 1189 |
|
|
mmu_bad_addr_we = 1'b0;
|
| 1190 |
|
|
end
|
| 1191 |
|
|
5'd10: // execute JR-type instr
|
| 1192 |
|
|
begin
|
| 1193 |
|
|
pc_src = 3'b000;
|
| 1194 |
|
|
pc_we = 1'b1;
|
| 1195 |
|
|
mar_we = 1'b0;
|
| 1196 |
|
|
ma_src = 1'bx;
|
| 1197 |
|
|
mmu_fnc = 3'b000;
|
| 1198 |
|
|
mdor_we = 1'b0;
|
| 1199 |
|
|
bus_stb = 1'b0;
|
| 1200 |
|
|
bus_we = 1'bx;
|
| 1201 |
|
|
bus_size = 2'bxx;
|
| 1202 |
|
|
mdir_we = 1'b0;
|
| 1203 |
|
|
mdir_sx = 1'bx;
|
| 1204 |
|
|
ir_we = 1'b0;
|
| 1205 |
|
|
reg_src2 = 2'bxx;
|
| 1206 |
|
|
reg_di2_src = 3'bxxx;
|
| 1207 |
|
|
reg_we2 = 1'b0;
|
| 1208 |
|
|
alu_src1 = 1'b1;
|
| 1209 |
|
|
alu_src2 = 3'bxxx;
|
| 1210 |
|
|
alu_fnc = 3'b010;
|
| 1211 |
|
|
shift_fnc = 2'bxx;
|
| 1212 |
|
|
muldiv_fnc = 3'bxxx;
|
| 1213 |
|
|
muldiv_start = 1'b0;
|
| 1214 |
|
|
sreg_we = 1'b0;
|
| 1215 |
|
|
psw_we = 1'b0;
|
| 1216 |
|
|
psw_new = 32'hxxxxxxxx;
|
| 1217 |
|
|
tlb_index_we = 1'b0;
|
| 1218 |
|
|
tlb_entry_hi_we = 1'b0;
|
| 1219 |
|
|
tlb_entry_lo_we = 1'b0;
|
| 1220 |
|
|
mmu_bad_addr_we = 1'b0;
|
| 1221 |
|
|
end
|
| 1222 |
|
|
5'd11: // execute LDST-type instr (1)
|
| 1223 |
|
|
begin
|
| 1224 |
|
|
pc_src = 3'bxxx;
|
| 1225 |
|
|
pc_we = 1'b0;
|
| 1226 |
|
|
mar_we = 1'b1;
|
| 1227 |
|
|
ma_src = 1'bx;
|
| 1228 |
|
|
mmu_fnc = 3'b000;
|
| 1229 |
|
|
mdor_we = 1'b1;
|
| 1230 |
|
|
bus_stb = 1'b0;
|
| 1231 |
|
|
bus_we = 1'bx;
|
| 1232 |
|
|
bus_size = 2'bxx;
|
| 1233 |
|
|
mdir_we = 1'b0;
|
| 1234 |
|
|
mdir_sx = 1'bx;
|
| 1235 |
|
|
ir_we = 1'b0;
|
| 1236 |
|
|
reg_src2 = 2'bxx;
|
| 1237 |
|
|
reg_di2_src = 3'bxxx;
|
| 1238 |
|
|
reg_we2 = 1'b0;
|
| 1239 |
|
|
alu_src1 = 1'b1;
|
| 1240 |
|
|
alu_src2 = 3'b010;
|
| 1241 |
|
|
alu_fnc = 3'b000;
|
| 1242 |
|
|
shift_fnc = 2'bxx;
|
| 1243 |
|
|
muldiv_fnc = 3'bxxx;
|
| 1244 |
|
|
muldiv_start = 1'b0;
|
| 1245 |
|
|
sreg_we = 1'b0;
|
| 1246 |
|
|
psw_we = 1'b0;
|
| 1247 |
|
|
psw_new = 32'hxxxxxxxx;
|
| 1248 |
|
|
tlb_index_we = 1'b0;
|
| 1249 |
|
|
tlb_entry_hi_we = 1'b0;
|
| 1250 |
|
|
tlb_entry_lo_we = 1'b0;
|
| 1251 |
|
|
mmu_bad_addr_we = 1'b0;
|
| 1252 |
|
|
end
|
| 1253 |
|
|
5'd12: // execute LD-type instr (addr xlat)
|
| 1254 |
|
|
begin
|
| 1255 |
|
|
pc_src = 3'bxxx;
|
| 1256 |
|
|
pc_we = 1'b0;
|
| 1257 |
|
|
mar_we = 1'b0;
|
| 1258 |
|
|
ma_src = 1'b1;
|
| 1259 |
|
|
mmu_fnc = (exc_prv_addr | exc_ill_addr) ? 3'b000 : 3'b001;
|
| 1260 |
|
|
mdor_we = 1'b0;
|
| 1261 |
|
|
bus_stb = 1'b0;
|
| 1262 |
|
|
bus_we = 1'b0; // get bad_accs right in case of exc
|
| 1263 |
|
|
bus_size = ldst_size; // enable illegal address detection
|
| 1264 |
|
|
mdir_we = 1'b0;
|
| 1265 |
|
|
mdir_sx = 1'bx;
|
| 1266 |
|
|
ir_we = 1'b0;
|
| 1267 |
|
|
reg_src2 = 2'bxx;
|
| 1268 |
|
|
reg_di2_src = 3'bxxx;
|
| 1269 |
|
|
reg_we2 = 1'b0;
|
| 1270 |
|
|
alu_src1 = 1'bx;
|
| 1271 |
|
|
alu_src2 = 3'bxxx;
|
| 1272 |
|
|
alu_fnc = 3'bxxx;
|
| 1273 |
|
|
shift_fnc = 2'bxx;
|
| 1274 |
|
|
muldiv_fnc = 3'bxxx;
|
| 1275 |
|
|
muldiv_start = 1'b0;
|
| 1276 |
|
|
sreg_we = 1'b0;
|
| 1277 |
|
|
psw_we = 1'b0;
|
| 1278 |
|
|
psw_new = 32'hxxxxxxxx;
|
| 1279 |
|
|
tlb_index_we = 1'b0;
|
| 1280 |
|
|
tlb_entry_hi_we = 1'b0;
|
| 1281 |
|
|
tlb_entry_lo_we = 1'b0;
|
| 1282 |
|
|
mmu_bad_addr_we = exc_prv_addr | exc_ill_addr;
|
| 1283 |
|
|
end
|
| 1284 |
|
|
5'd13: // execute LD-type instr (3)
|
| 1285 |
|
|
begin
|
| 1286 |
|
|
pc_src = 3'bxxx;
|
| 1287 |
|
|
pc_we = 1'b0;
|
| 1288 |
|
|
mar_we = 1'b0;
|
| 1289 |
|
|
ma_src = 1'bx;
|
| 1290 |
|
|
mmu_fnc = 3'b000;
|
| 1291 |
|
|
mdor_we = 1'b0;
|
| 1292 |
|
|
bus_stb = 1'b0;
|
| 1293 |
|
|
bus_we = 1'bx;
|
| 1294 |
|
|
bus_size = ldst_size;
|
| 1295 |
|
|
mdir_we = 1'b0;
|
| 1296 |
|
|
mdir_sx = opcode[0];
|
| 1297 |
|
|
ir_we = 1'b0;
|
| 1298 |
|
|
reg_src2 = 2'b00;
|
| 1299 |
|
|
reg_di2_src = 3'b011;
|
| 1300 |
|
|
reg_we2 = 1'b1;
|
| 1301 |
|
|
alu_src1 = 1'bx;
|
| 1302 |
|
|
alu_src2 = 3'bxxx;
|
| 1303 |
|
|
alu_fnc = 3'bxxx;
|
| 1304 |
|
|
shift_fnc = 2'bxx;
|
| 1305 |
|
|
muldiv_fnc = 3'bxxx;
|
| 1306 |
|
|
muldiv_start = 1'b0;
|
| 1307 |
|
|
sreg_we = 1'b0;
|
| 1308 |
|
|
psw_we = 1'b0;
|
| 1309 |
|
|
psw_new = 32'hxxxxxxxx;
|
| 1310 |
|
|
tlb_index_we = 1'b0;
|
| 1311 |
|
|
tlb_entry_hi_we = 1'b0;
|
| 1312 |
|
|
tlb_entry_lo_we = 1'b0;
|
| 1313 |
|
|
mmu_bad_addr_we = 1'b0;
|
| 1314 |
|
|
end
|
| 1315 |
|
|
5'd14: // execute ST-type instr (addr xlat)
|
| 1316 |
|
|
begin
|
| 1317 |
|
|
pc_src = 3'bxxx;
|
| 1318 |
|
|
pc_we = 1'b0;
|
| 1319 |
|
|
mar_we = 1'b0;
|
| 1320 |
|
|
ma_src = 1'b1;
|
| 1321 |
|
|
mmu_fnc = (exc_prv_addr | exc_ill_addr) ? 3'b000 : 3'b001;
|
| 1322 |
|
|
mdor_we = 1'b0;
|
| 1323 |
|
|
bus_stb = 1'b0;
|
| 1324 |
|
|
bus_we = 1'b1; // get bad_accs right in case of exc
|
| 1325 |
|
|
bus_size = ldst_size; // enable illegal address detection
|
| 1326 |
|
|
mdir_we = 1'b0;
|
| 1327 |
|
|
mdir_sx = 1'bx;
|
| 1328 |
|
|
ir_we = 1'b0;
|
| 1329 |
|
|
reg_src2 = 2'bxx;
|
| 1330 |
|
|
reg_di2_src = 3'bxxx;
|
| 1331 |
|
|
reg_we2 = 1'b0;
|
| 1332 |
|
|
alu_src1 = 1'bx;
|
| 1333 |
|
|
alu_src2 = 3'bxxx;
|
| 1334 |
|
|
alu_fnc = 3'bxxx;
|
| 1335 |
|
|
shift_fnc = 2'bxx;
|
| 1336 |
|
|
muldiv_fnc = 3'bxxx;
|
| 1337 |
|
|
muldiv_start = 1'b0;
|
| 1338 |
|
|
sreg_we = 1'b0;
|
| 1339 |
|
|
psw_we = 1'b0;
|
| 1340 |
|
|
psw_new = 32'hxxxxxxxx;
|
| 1341 |
|
|
tlb_index_we = 1'b0;
|
| 1342 |
|
|
tlb_entry_hi_we = 1'b0;
|
| 1343 |
|
|
tlb_entry_lo_we = 1'b0;
|
| 1344 |
|
|
mmu_bad_addr_we = exc_prv_addr | exc_ill_addr;
|
| 1345 |
|
|
end
|
| 1346 |
|
|
5'd15: // interrupt
|
| 1347 |
|
|
begin
|
| 1348 |
|
|
pc_src = (psw[27] == 0) ? 3'b010 : 3'b011;
|
| 1349 |
|
|
pc_we = 1'b1;
|
| 1350 |
|
|
mar_we = 1'b0;
|
| 1351 |
|
|
ma_src = 1'bx;
|
| 1352 |
|
|
mmu_fnc = 3'b000;
|
| 1353 |
|
|
mdor_we = 1'b0;
|
| 1354 |
|
|
bus_stb = 1'b0;
|
| 1355 |
|
|
bus_we = 1'bx;
|
| 1356 |
|
|
bus_size = 2'bxx;
|
| 1357 |
|
|
mdir_we = 1'b0;
|
| 1358 |
|
|
mdir_sx = 1'bx;
|
| 1359 |
|
|
ir_we = 1'b0;
|
| 1360 |
|
|
reg_src2 = 2'b11;
|
| 1361 |
|
|
reg_di2_src = 3'b000;
|
| 1362 |
|
|
reg_we2 = 1'b1;
|
| 1363 |
|
|
alu_src1 = 1'b0;
|
| 1364 |
|
|
alu_src2 = 3'bxxx;
|
| 1365 |
|
|
alu_fnc = 3'b010;
|
| 1366 |
|
|
shift_fnc = 2'bxx;
|
| 1367 |
|
|
muldiv_fnc = 3'bxxx;
|
| 1368 |
|
|
muldiv_start = 1'b0;
|
| 1369 |
|
|
sreg_we = 1'b0;
|
| 1370 |
|
|
psw_we = 1'b1;
|
| 1371 |
|
|
psw_new = {
|
| 1372 |
|
|
psw[31:28],
|
| 1373 |
|
|
psw[27],
|
| 1374 |
|
|
1'b0, psw[26], psw[25],
|
| 1375 |
|
|
1'b0, psw[23], psw[22],
|
| 1376 |
|
|
1'b0, irq_priority,
|
| 1377 |
|
|
psw[15:0]
|
| 1378 |
|
|
};
|
| 1379 |
|
|
tlb_index_we = 1'b0;
|
| 1380 |
|
|
tlb_entry_hi_we = 1'b0;
|
| 1381 |
|
|
tlb_entry_lo_we = 1'b0;
|
| 1382 |
|
|
mmu_bad_addr_we = 1'b0;
|
| 1383 |
|
|
end
|
| 1384 |
|
|
5'd16: // extra state for RRR shift instr
|
| 1385 |
|
|
begin
|
| 1386 |
|
|
pc_src = 3'bxxx;
|
| 1387 |
|
|
pc_we = 1'b0;
|
| 1388 |
|
|
mar_we = 1'b0;
|
| 1389 |
|
|
ma_src = 1'bx;
|
| 1390 |
|
|
mmu_fnc = 3'b000;
|
| 1391 |
|
|
mdor_we = 1'b0;
|
| 1392 |
|
|
bus_stb = 1'b0;
|
| 1393 |
|
|
bus_we = 1'bx;
|
| 1394 |
|
|
bus_size = 2'bxx;
|
| 1395 |
|
|
mdir_we = 1'b0;
|
| 1396 |
|
|
mdir_sx = 1'bx;
|
| 1397 |
|
|
ir_we = 1'b0;
|
| 1398 |
|
|
reg_src2 = 2'b01;
|
| 1399 |
|
|
reg_di2_src = 3'b001;
|
| 1400 |
|
|
reg_we2 = 1'b1;
|
| 1401 |
|
|
alu_src1 = 1'bx;
|
| 1402 |
|
|
alu_src2 = 3'bxxx;
|
| 1403 |
|
|
alu_fnc = 3'bxxx;
|
| 1404 |
|
|
shift_fnc = 2'bxx;
|
| 1405 |
|
|
muldiv_fnc = 3'bxxx;
|
| 1406 |
|
|
muldiv_start = 1'b0;
|
| 1407 |
|
|
sreg_we = 1'b0;
|
| 1408 |
|
|
psw_we = 1'b0;
|
| 1409 |
|
|
psw_new = 32'hxxxxxxxx;
|
| 1410 |
|
|
tlb_index_we = 1'b0;
|
| 1411 |
|
|
tlb_entry_hi_we = 1'b0;
|
| 1412 |
|
|
tlb_entry_lo_we = 1'b0;
|
| 1413 |
|
|
mmu_bad_addr_we = 1'b0;
|
| 1414 |
|
|
end
|
| 1415 |
|
|
5'd17: // extra state for RRH shift instr
|
| 1416 |
|
|
begin
|
| 1417 |
|
|
pc_src = 3'bxxx;
|
| 1418 |
|
|
pc_we = 1'b0;
|
| 1419 |
|
|
mar_we = 1'b0;
|
| 1420 |
|
|
ma_src = 1'bx;
|
| 1421 |
|
|
mmu_fnc = 3'b000;
|
| 1422 |
|
|
mdor_we = 1'b0;
|
| 1423 |
|
|
bus_stb = 1'b0;
|
| 1424 |
|
|
bus_we = 1'bx;
|
| 1425 |
|
|
bus_size = 2'bxx;
|
| 1426 |
|
|
mdir_we = 1'b0;
|
| 1427 |
|
|
mdir_sx = 1'bx;
|
| 1428 |
|
|
ir_we = 1'b0;
|
| 1429 |
|
|
reg_src2 = 2'b00;
|
| 1430 |
|
|
reg_di2_src = 3'b001;
|
| 1431 |
|
|
reg_we2 = 1'b1;
|
| 1432 |
|
|
alu_src1 = 1'bx;
|
| 1433 |
|
|
alu_src2 = 3'bxxx;
|
| 1434 |
|
|
alu_fnc = 3'bxxx;
|
| 1435 |
|
|
shift_fnc = 2'bxx;
|
| 1436 |
|
|
muldiv_fnc = 3'bxxx;
|
| 1437 |
|
|
muldiv_start = 1'b0;
|
| 1438 |
|
|
sreg_we = 1'b0;
|
| 1439 |
|
|
psw_we = 1'b0;
|
| 1440 |
|
|
psw_new = 32'hxxxxxxxx;
|
| 1441 |
|
|
tlb_index_we = 1'b0;
|
| 1442 |
|
|
tlb_entry_hi_we = 1'b0;
|
| 1443 |
|
|
tlb_entry_lo_we = 1'b0;
|
| 1444 |
|
|
mmu_bad_addr_we = 1'b0;
|
| 1445 |
|
|
end
|
| 1446 |
|
|
5'd18: // extra state for RRR muldiv instr
|
| 1447 |
|
|
begin
|
| 1448 |
|
|
pc_src = 3'bxxx;
|
| 1449 |
|
|
pc_we = 1'b0;
|
| 1450 |
|
|
mar_we = 1'b0;
|
| 1451 |
|
|
ma_src = 1'bx;
|
| 1452 |
|
|
mmu_fnc = 3'b000;
|
| 1453 |
|
|
mdor_we = 1'b0;
|
| 1454 |
|
|
bus_stb = 1'b0;
|
| 1455 |
|
|
bus_we = 1'bx;
|
| 1456 |
|
|
bus_size = 2'bxx;
|
| 1457 |
|
|
mdir_we = 1'b0;
|
| 1458 |
|
|
mdir_sx = 1'bx;
|
| 1459 |
|
|
ir_we = 1'b0;
|
| 1460 |
|
|
reg_src2 = 2'b01;
|
| 1461 |
|
|
reg_di2_src = 3'b010;
|
| 1462 |
|
|
reg_we2 = muldiv_done & ~muldiv_error;
|
| 1463 |
|
|
alu_src1 = 1'bx;
|
| 1464 |
|
|
alu_src2 = 3'bxxx;
|
| 1465 |
|
|
alu_fnc = 3'bxxx;
|
| 1466 |
|
|
shift_fnc = 2'bxx;
|
| 1467 |
|
|
muldiv_fnc = 3'bxxx;
|
| 1468 |
|
|
muldiv_start = 1'b0;
|
| 1469 |
|
|
sreg_we = 1'b0;
|
| 1470 |
|
|
psw_we = 1'b0;
|
| 1471 |
|
|
psw_new = 32'hxxxxxxxx;
|
| 1472 |
|
|
tlb_index_we = 1'b0;
|
| 1473 |
|
|
tlb_entry_hi_we = 1'b0;
|
| 1474 |
|
|
tlb_entry_lo_we = 1'b0;
|
| 1475 |
|
|
mmu_bad_addr_we = 1'b0;
|
| 1476 |
|
|
end
|
| 1477 |
|
|
5'd19: // extra state for RRS muldiv instr
|
| 1478 |
|
|
begin
|
| 1479 |
|
|
pc_src = 3'bxxx;
|
| 1480 |
|
|
pc_we = 1'b0;
|
| 1481 |
|
|
mar_we = 1'b0;
|
| 1482 |
|
|
ma_src = 1'bx;
|
| 1483 |
|
|
mmu_fnc = 3'b000;
|
| 1484 |
|
|
mdor_we = 1'b0;
|
| 1485 |
|
|
bus_stb = 1'b0;
|
| 1486 |
|
|
bus_we = 1'bx;
|
| 1487 |
|
|
bus_size = 2'bxx;
|
| 1488 |
|
|
mdir_we = 1'b0;
|
| 1489 |
|
|
mdir_sx = 1'bx;
|
| 1490 |
|
|
ir_we = 1'b0;
|
| 1491 |
|
|
reg_src2 = 2'b00;
|
| 1492 |
|
|
reg_di2_src = 3'b010;
|
| 1493 |
|
|
reg_we2 = muldiv_done & ~muldiv_error;
|
| 1494 |
|
|
alu_src1 = 1'bx;
|
| 1495 |
|
|
alu_src2 = 3'bxxx;
|
| 1496 |
|
|
alu_fnc = 3'bxxx;
|
| 1497 |
|
|
shift_fnc = 2'bxx;
|
| 1498 |
|
|
muldiv_fnc = 3'bxxx;
|
| 1499 |
|
|
muldiv_start = 1'b0;
|
| 1500 |
|
|
sreg_we = 1'b0;
|
| 1501 |
|
|
psw_we = 1'b0;
|
| 1502 |
|
|
psw_new = 32'hxxxxxxxx;
|
| 1503 |
|
|
tlb_index_we = 1'b0;
|
| 1504 |
|
|
tlb_entry_hi_we = 1'b0;
|
| 1505 |
|
|
tlb_entry_lo_we = 1'b0;
|
| 1506 |
|
|
mmu_bad_addr_we = 1'b0;
|
| 1507 |
|
|
end
|
| 1508 |
|
|
5'd20: // extra state for RRH muldiv instr
|
| 1509 |
|
|
begin
|
| 1510 |
|
|
pc_src = 3'bxxx;
|
| 1511 |
|
|
pc_we = 1'b0;
|
| 1512 |
|
|
mar_we = 1'b0;
|
| 1513 |
|
|
ma_src = 1'bx;
|
| 1514 |
|
|
mmu_fnc = 3'b000;
|
| 1515 |
|
|
mdor_we = 1'b0;
|
| 1516 |
|
|
bus_stb = 1'b0;
|
| 1517 |
|
|
bus_we = 1'bx;
|
| 1518 |
|
|
bus_size = 2'bxx;
|
| 1519 |
|
|
mdir_we = 1'b0;
|
| 1520 |
|
|
mdir_sx = 1'bx;
|
| 1521 |
|
|
ir_we = 1'b0;
|
| 1522 |
|
|
reg_src2 = 2'b00;
|
| 1523 |
|
|
reg_di2_src = 3'b010;
|
| 1524 |
|
|
reg_we2 = muldiv_done & ~muldiv_error;
|
| 1525 |
|
|
alu_src1 = 1'bx;
|
| 1526 |
|
|
alu_src2 = 3'bxxx;
|
| 1527 |
|
|
alu_fnc = 3'bxxx;
|
| 1528 |
|
|
shift_fnc = 2'bxx;
|
| 1529 |
|
|
muldiv_fnc = 3'bxxx;
|
| 1530 |
|
|
muldiv_start = 1'b0;
|
| 1531 |
|
|
sreg_we = 1'b0;
|
| 1532 |
|
|
psw_we = 1'b0;
|
| 1533 |
|
|
psw_new = 32'hxxxxxxxx;
|
| 1534 |
|
|
tlb_index_we = 1'b0;
|
| 1535 |
|
|
tlb_entry_hi_we = 1'b0;
|
| 1536 |
|
|
tlb_entry_lo_we = 1'b0;
|
| 1537 |
|
|
mmu_bad_addr_we = 1'b0;
|
| 1538 |
|
|
end
|
| 1539 |
|
|
5'd21: // execute mvfs instr
|
| 1540 |
|
|
begin
|
| 1541 |
|
|
pc_src = 3'bxxx;
|
| 1542 |
|
|
pc_we = 1'b0;
|
| 1543 |
|
|
mar_we = 1'b0;
|
| 1544 |
|
|
ma_src = 1'bx;
|
| 1545 |
|
|
mmu_fnc = 3'b000;
|
| 1546 |
|
|
mdor_we = 1'b0;
|
| 1547 |
|
|
bus_stb = 1'b0;
|
| 1548 |
|
|
bus_we = 1'bx;
|
| 1549 |
|
|
bus_size = 2'bxx;
|
| 1550 |
|
|
mdir_we = 1'b0;
|
| 1551 |
|
|
mdir_sx = 1'bx;
|
| 1552 |
|
|
ir_we = 1'b0;
|
| 1553 |
|
|
reg_src2 = 2'b00;
|
| 1554 |
|
|
reg_di2_src = 3'b100;
|
| 1555 |
|
|
reg_we2 = 1'b1;
|
| 1556 |
|
|
alu_src1 = 1'bx;
|
| 1557 |
|
|
alu_src2 = 3'bxxx;
|
| 1558 |
|
|
alu_fnc = 3'bxxx;
|
| 1559 |
|
|
shift_fnc = 2'bxx;
|
| 1560 |
|
|
muldiv_fnc = 3'bxxx;
|
| 1561 |
|
|
muldiv_start = 1'b0;
|
| 1562 |
|
|
sreg_we = 1'b0;
|
| 1563 |
|
|
psw_we = 1'b0;
|
| 1564 |
|
|
psw_new = 32'hxxxxxxxx;
|
| 1565 |
|
|
tlb_index_we = 1'b0;
|
| 1566 |
|
|
tlb_entry_hi_we = 1'b0;
|
| 1567 |
|
|
tlb_entry_lo_we = 1'b0;
|
| 1568 |
|
|
mmu_bad_addr_we = 1'b0;
|
| 1569 |
|
|
end
|
| 1570 |
|
|
5'd22: // execute mvts instr
|
| 1571 |
|
|
begin
|
| 1572 |
|
|
pc_src = 3'bxxx;
|
| 1573 |
|
|
pc_we = 1'b0;
|
| 1574 |
|
|
mar_we = 1'b0;
|
| 1575 |
|
|
ma_src = 1'bx;
|
| 1576 |
|
|
mmu_fnc = 3'b000;
|
| 1577 |
|
|
mdor_we = 1'b0;
|
| 1578 |
|
|
bus_stb = 1'b0;
|
| 1579 |
|
|
bus_we = 1'bx;
|
| 1580 |
|
|
bus_size = 2'bxx;
|
| 1581 |
|
|
mdir_we = 1'b0;
|
| 1582 |
|
|
mdir_sx = 1'bx;
|
| 1583 |
|
|
ir_we = 1'b0;
|
| 1584 |
|
|
reg_src2 = 2'bxx;
|
| 1585 |
|
|
reg_di2_src = 3'bxxx;
|
| 1586 |
|
|
reg_we2 = 1'b0;
|
| 1587 |
|
|
alu_src1 = 1'bx;
|
| 1588 |
|
|
alu_src2 = 3'bxxx;
|
| 1589 |
|
|
alu_fnc = 3'bxxx;
|
| 1590 |
|
|
shift_fnc = 2'bxx;
|
| 1591 |
|
|
muldiv_fnc = 3'bxxx;
|
| 1592 |
|
|
muldiv_start = 1'b0;
|
| 1593 |
|
|
sreg_we = 1'b1;
|
| 1594 |
|
|
psw_we = 1'b0;
|
| 1595 |
|
|
psw_new = 32'hxxxxxxxx;
|
| 1596 |
|
|
tlb_index_we = 1'b0;
|
| 1597 |
|
|
tlb_entry_hi_we = 1'b0;
|
| 1598 |
|
|
tlb_entry_lo_we = 1'b0;
|
| 1599 |
|
|
mmu_bad_addr_we = 1'b0;
|
| 1600 |
|
|
end
|
| 1601 |
|
|
5'd23: // execute rfx instr
|
| 1602 |
|
|
begin
|
| 1603 |
|
|
pc_src = 3'b000;
|
| 1604 |
|
|
pc_we = 1'b1;
|
| 1605 |
|
|
mar_we = 1'b0;
|
| 1606 |
|
|
ma_src = 1'bx;
|
| 1607 |
|
|
mmu_fnc = 3'b000;
|
| 1608 |
|
|
mdor_we = 1'b0;
|
| 1609 |
|
|
bus_stb = 1'b0;
|
| 1610 |
|
|
bus_we = 1'bx;
|
| 1611 |
|
|
bus_size = 2'bxx;
|
| 1612 |
|
|
mdir_we = 1'b0;
|
| 1613 |
|
|
mdir_sx = 1'bx;
|
| 1614 |
|
|
ir_we = 1'b0;
|
| 1615 |
|
|
reg_src2 = 2'bxx;
|
| 1616 |
|
|
reg_di2_src = 3'bxxx;
|
| 1617 |
|
|
reg_we2 = 1'b0;
|
| 1618 |
|
|
alu_src1 = 1'bx;
|
| 1619 |
|
|
alu_src2 = 3'b001;
|
| 1620 |
|
|
alu_fnc = 3'b011;
|
| 1621 |
|
|
shift_fnc = 2'bxx;
|
| 1622 |
|
|
muldiv_fnc = 3'bxxx;
|
| 1623 |
|
|
muldiv_start = 1'b0;
|
| 1624 |
|
|
sreg_we = 1'b0;
|
| 1625 |
|
|
psw_we = 1'b1;
|
| 1626 |
|
|
psw_new = {
|
| 1627 |
|
|
psw[31:28],
|
| 1628 |
|
|
psw[27],
|
| 1629 |
|
|
psw[25], psw[24], psw[24],
|
| 1630 |
|
|
psw[22], psw[21], psw[21],
|
| 1631 |
|
|
psw[20:16],
|
| 1632 |
|
|
psw[15:0]
|
| 1633 |
|
|
};
|
| 1634 |
|
|
tlb_index_we = 1'b0;
|
| 1635 |
|
|
tlb_entry_hi_we = 1'b0;
|
| 1636 |
|
|
tlb_entry_lo_we = 1'b0;
|
| 1637 |
|
|
mmu_bad_addr_we = 1'b0;
|
| 1638 |
|
|
end
|
| 1639 |
|
|
5'd24: // irq_trigger check for mvts and rfx
|
| 1640 |
|
|
begin
|
| 1641 |
|
|
pc_src = 3'bxxx;
|
| 1642 |
|
|
pc_we = 1'b0;
|
| 1643 |
|
|
mar_we = 1'b0;
|
| 1644 |
|
|
ma_src = 1'bx;
|
| 1645 |
|
|
mmu_fnc = 3'b000;
|
| 1646 |
|
|
mdor_we = 1'b0;
|
| 1647 |
|
|
bus_stb = 1'b0;
|
| 1648 |
|
|
bus_we = 1'bx;
|
| 1649 |
|
|
bus_size = 2'bxx;
|
| 1650 |
|
|
mdir_we = 1'b0;
|
| 1651 |
|
|
mdir_sx = 1'bx;
|
| 1652 |
|
|
ir_we = 1'b0;
|
| 1653 |
|
|
reg_src2 = 2'bxx;
|
| 1654 |
|
|
reg_di2_src = 3'bxxx;
|
| 1655 |
|
|
reg_we2 = 1'b0;
|
| 1656 |
|
|
alu_src1 = 1'bx;
|
| 1657 |
|
|
alu_src2 = 3'bxxx;
|
| 1658 |
|
|
alu_fnc = 3'bxxx;
|
| 1659 |
|
|
shift_fnc = 2'bxx;
|
| 1660 |
|
|
muldiv_fnc = 3'bxxx;
|
| 1661 |
|
|
muldiv_start = 1'b0;
|
| 1662 |
|
|
sreg_we = 1'b0;
|
| 1663 |
|
|
psw_we = 1'b0;
|
| 1664 |
|
|
psw_new = 32'hxxxxxxxx;
|
| 1665 |
|
|
tlb_index_we = 1'b0;
|
| 1666 |
|
|
tlb_entry_hi_we = 1'b0;
|
| 1667 |
|
|
tlb_entry_lo_we = 1'b0;
|
| 1668 |
|
|
mmu_bad_addr_we = 1'b0;
|
| 1669 |
|
|
end
|
| 1670 |
|
|
5'd25: // exception (locus is PC-4)
|
| 1671 |
|
|
begin
|
| 1672 |
|
|
pc_src = (psw[27] != 0) ?
|
| 1673 |
|
|
((tlb_umissed != 0) ? 3'b101 : 3'b011) :
|
| 1674 |
|
|
((tlb_umissed != 0) ? 3'b100 : 3'b010);
|
| 1675 |
|
|
pc_we = 1'b1;
|
| 1676 |
|
|
mar_we = 1'b0;
|
| 1677 |
|
|
ma_src = 1'bx;
|
| 1678 |
|
|
mmu_fnc = 3'b000;
|
| 1679 |
|
|
mdor_we = 1'b0;
|
| 1680 |
|
|
bus_stb = 1'b0;
|
| 1681 |
|
|
bus_we = 1'bx;
|
| 1682 |
|
|
bus_size = 2'bxx;
|
| 1683 |
|
|
mdir_we = 1'b0;
|
| 1684 |
|
|
mdir_sx = 1'bx;
|
| 1685 |
|
|
ir_we = 1'b0;
|
| 1686 |
|
|
reg_src2 = 2'b11;
|
| 1687 |
|
|
reg_di2_src = 3'b000;
|
| 1688 |
|
|
reg_we2 = 1'b1;
|
| 1689 |
|
|
alu_src1 = 1'b0;
|
| 1690 |
|
|
alu_src2 = 3'b000;
|
| 1691 |
|
|
alu_fnc = 3'b001;
|
| 1692 |
|
|
shift_fnc = 2'bxx;
|
| 1693 |
|
|
muldiv_fnc = 3'bxxx;
|
| 1694 |
|
|
muldiv_start = 1'b0;
|
| 1695 |
|
|
sreg_we = 1'b0;
|
| 1696 |
|
|
psw_we = 1'b1;
|
| 1697 |
|
|
psw_new = {
|
| 1698 |
|
|
psw[31:28],
|
| 1699 |
|
|
psw[27],
|
| 1700 |
|
|
1'b0, psw[26], psw[25],
|
| 1701 |
|
|
1'b0, psw[23], psw[22],
|
| 1702 |
|
|
1'b1, exc_priority,
|
| 1703 |
|
|
psw[15:0]
|
| 1704 |
|
|
};
|
| 1705 |
|
|
tlb_index_we = 1'b0;
|
| 1706 |
|
|
tlb_entry_hi_we = 1'b0;
|
| 1707 |
|
|
tlb_entry_lo_we = 1'b0;
|
| 1708 |
|
|
mmu_bad_addr_we = 1'b0;
|
| 1709 |
|
|
end
|
| 1710 |
|
|
5'd26: // exception (locus is PC)
|
| 1711 |
|
|
begin
|
| 1712 |
|
|
pc_src = (psw[27] != 0) ?
|
| 1713 |
|
|
((tlb_umissed != 0) ? 3'b101 : 3'b011) :
|
| 1714 |
|
|
((tlb_umissed != 0) ? 3'b100 : 3'b010);
|
| 1715 |
|
|
pc_we = 1'b1;
|
| 1716 |
|
|
mar_we = 1'b0;
|
| 1717 |
|
|
ma_src = 1'bx;
|
| 1718 |
|
|
mmu_fnc = 3'b000;
|
| 1719 |
|
|
mdor_we = 1'b0;
|
| 1720 |
|
|
bus_stb = 1'b0;
|
| 1721 |
|
|
bus_we = 1'bx;
|
| 1722 |
|
|
bus_size = 2'bxx;
|
| 1723 |
|
|
mdir_we = 1'b0;
|
| 1724 |
|
|
mdir_sx = 1'bx;
|
| 1725 |
|
|
ir_we = 1'b0;
|
| 1726 |
|
|
reg_src2 = 2'b11;
|
| 1727 |
|
|
reg_di2_src = 3'b000;
|
| 1728 |
|
|
reg_we2 = 1'b1;
|
| 1729 |
|
|
alu_src1 = 1'b0;
|
| 1730 |
|
|
alu_src2 = 3'bxxx;
|
| 1731 |
|
|
alu_fnc = 3'b010;
|
| 1732 |
|
|
shift_fnc = 2'bxx;
|
| 1733 |
|
|
muldiv_fnc = 3'bxxx;
|
| 1734 |
|
|
muldiv_start = 1'b0;
|
| 1735 |
|
|
sreg_we = 1'b0;
|
| 1736 |
|
|
psw_we = 1'b1;
|
| 1737 |
|
|
psw_new = {
|
| 1738 |
|
|
psw[31:28],
|
| 1739 |
|
|
psw[27],
|
| 1740 |
|
|
1'b0, psw[26], psw[25],
|
| 1741 |
|
|
1'b0, psw[23], psw[22],
|
| 1742 |
|
|
1'b1, exc_priority,
|
| 1743 |
|
|
psw[15:0]
|
| 1744 |
|
|
};
|
| 1745 |
|
|
tlb_index_we = 1'b0;
|
| 1746 |
|
|
tlb_entry_hi_we = 1'b0;
|
| 1747 |
|
|
tlb_entry_lo_we = 1'b0;
|
| 1748 |
|
|
mmu_bad_addr_we = 1'b0;
|
| 1749 |
|
|
end
|
| 1750 |
|
|
5'd27: // execute TLB instr
|
| 1751 |
|
|
begin
|
| 1752 |
|
|
pc_src = 3'bxxx;
|
| 1753 |
|
|
pc_we = 1'b0;
|
| 1754 |
|
|
mar_we = 1'b0;
|
| 1755 |
|
|
ma_src = 1'bx;
|
| 1756 |
|
|
mmu_fnc = opcode[2:0];
|
| 1757 |
|
|
mdor_we = 1'b0;
|
| 1758 |
|
|
bus_stb = 1'b0;
|
| 1759 |
|
|
bus_we = 1'bx;
|
| 1760 |
|
|
bus_size = 2'bxx;
|
| 1761 |
|
|
mdir_we = 1'b0;
|
| 1762 |
|
|
mdir_sx = 1'bx;
|
| 1763 |
|
|
ir_we = 1'b0;
|
| 1764 |
|
|
reg_src2 = 2'bxx;
|
| 1765 |
|
|
reg_di2_src = 3'bxxx;
|
| 1766 |
|
|
reg_we2 = 1'b0;
|
| 1767 |
|
|
alu_src1 = 1'bx;
|
| 1768 |
|
|
alu_src2 = 3'bxxx;
|
| 1769 |
|
|
alu_fnc = 3'bxxx;
|
| 1770 |
|
|
shift_fnc = 2'bxx;
|
| 1771 |
|
|
muldiv_fnc = 3'bxxx;
|
| 1772 |
|
|
muldiv_start = 1'b0;
|
| 1773 |
|
|
sreg_we = 1'b0;
|
| 1774 |
|
|
psw_we = 1'b0;
|
| 1775 |
|
|
psw_new = 32'hxxxxxxxx;
|
| 1776 |
|
|
tlb_index_we = (opcode[2:0] == 3'b010) ? 1 : 0;
|
| 1777 |
|
|
tlb_entry_hi_we = (opcode[2:0] == 3'b100) ? 1 : 0;
|
| 1778 |
|
|
tlb_entry_lo_we = (opcode[2:0] == 3'b100) ? 1 : 0;
|
| 1779 |
|
|
mmu_bad_addr_we = 1'b0;
|
| 1780 |
|
|
end
|
| 1781 |
|
|
5'd28: // fetch instr (bus cycle)
|
| 1782 |
|
|
begin
|
| 1783 |
|
|
pc_src = 3'bxxx;
|
| 1784 |
|
|
pc_we = 1'b0;
|
| 1785 |
|
|
mar_we = 1'b0;
|
| 1786 |
|
|
ma_src = 1'b0; // hold vaddr for latching in bad addr reg
|
| 1787 |
|
|
mmu_fnc = 3'b000;
|
| 1788 |
|
|
mdor_we = 1'b0;
|
| 1789 |
|
|
bus_stb = ~exc_tlb_but_wrtprot;
|
| 1790 |
|
|
bus_we = 1'b0;
|
| 1791 |
|
|
bus_size = 2'b10;
|
| 1792 |
|
|
mdir_we = 1'b0;
|
| 1793 |
|
|
mdir_sx = 1'bx;
|
| 1794 |
|
|
ir_we = 1'b1;
|
| 1795 |
|
|
reg_src2 = 2'bxx;
|
| 1796 |
|
|
reg_di2_src = 3'bxxx;
|
| 1797 |
|
|
reg_we2 = 1'b0;
|
| 1798 |
|
|
alu_src1 = 1'bx;
|
| 1799 |
|
|
alu_src2 = 3'bxxx;
|
| 1800 |
|
|
alu_fnc = 3'bxxx;
|
| 1801 |
|
|
shift_fnc = 2'bxx;
|
| 1802 |
|
|
muldiv_fnc = 3'bxxx;
|
| 1803 |
|
|
muldiv_start = 1'b0;
|
| 1804 |
|
|
sreg_we = 1'b0;
|
| 1805 |
|
|
psw_we = 1'b0;
|
| 1806 |
|
|
psw_new = 32'hxxxxxxxx;
|
| 1807 |
|
|
tlb_index_we = 1'b0;
|
| 1808 |
|
|
tlb_entry_hi_we = exc_tlb_but_wrtprot;
|
| 1809 |
|
|
tlb_entry_lo_we = 1'b0;
|
| 1810 |
|
|
mmu_bad_addr_we = exc_tlb_but_wrtprot;
|
| 1811 |
|
|
end
|
| 1812 |
|
|
5'd29: // execute LD-type instr (bus cycle)
|
| 1813 |
|
|
begin
|
| 1814 |
|
|
pc_src = 3'bxxx;
|
| 1815 |
|
|
pc_we = 1'b0;
|
| 1816 |
|
|
mar_we = 1'b0;
|
| 1817 |
|
|
ma_src = 1'b1; // hold vaddr for latching in bad addr reg
|
| 1818 |
|
|
mmu_fnc = 3'b000;
|
| 1819 |
|
|
mdor_we = 1'b0;
|
| 1820 |
|
|
bus_stb = ~exc_tlb_but_wrtprot;
|
| 1821 |
|
|
bus_we = 1'b0;
|
| 1822 |
|
|
bus_size = ldst_size;
|
| 1823 |
|
|
mdir_we = 1'b1;
|
| 1824 |
|
|
mdir_sx = 1'bx;
|
| 1825 |
|
|
ir_we = 1'b0;
|
| 1826 |
|
|
reg_src2 = 2'bxx;
|
| 1827 |
|
|
reg_di2_src = 3'bxxx;
|
| 1828 |
|
|
reg_we2 = 1'b0;
|
| 1829 |
|
|
alu_src1 = 1'bx;
|
| 1830 |
|
|
alu_src2 = 3'bxxx;
|
| 1831 |
|
|
alu_fnc = 3'bxxx;
|
| 1832 |
|
|
shift_fnc = 2'bxx;
|
| 1833 |
|
|
muldiv_fnc = 3'bxxx;
|
| 1834 |
|
|
muldiv_start = 1'b0;
|
| 1835 |
|
|
sreg_we = 1'b0;
|
| 1836 |
|
|
psw_we = 1'b0;
|
| 1837 |
|
|
psw_new = 32'hxxxxxxxx;
|
| 1838 |
|
|
tlb_index_we = 1'b0;
|
| 1839 |
|
|
tlb_entry_hi_we = exc_tlb_but_wrtprot;
|
| 1840 |
|
|
tlb_entry_lo_we = 1'b0;
|
| 1841 |
|
|
mmu_bad_addr_we = exc_tlb_but_wrtprot;
|
| 1842 |
|
|
end
|
| 1843 |
|
|
5'd30: // execute ST-type instr (bus cycle)
|
| 1844 |
|
|
begin
|
| 1845 |
|
|
pc_src = 3'bxxx;
|
| 1846 |
|
|
pc_we = 1'b0;
|
| 1847 |
|
|
mar_we = 1'b0;
|
| 1848 |
|
|
ma_src = 1'b1; // hold vaddr for latching in bad addr reg
|
| 1849 |
|
|
mmu_fnc = 3'b000;
|
| 1850 |
|
|
mdor_we = 1'b0;
|
| 1851 |
|
|
bus_stb = ~exc_tlb_any;
|
| 1852 |
|
|
bus_we = 1'b1;
|
| 1853 |
|
|
bus_size = ldst_size;
|
| 1854 |
|
|
mdir_we = 1'b0;
|
| 1855 |
|
|
mdir_sx = 1'bx;
|
| 1856 |
|
|
ir_we = 1'b0;
|
| 1857 |
|
|
reg_src2 = 2'bxx;
|
| 1858 |
|
|
reg_di2_src = 3'bxxx;
|
| 1859 |
|
|
reg_we2 = 1'b0;
|
| 1860 |
|
|
alu_src1 = 1'bx;
|
| 1861 |
|
|
alu_src2 = 3'bxxx;
|
| 1862 |
|
|
alu_fnc = 3'bxxx;
|
| 1863 |
|
|
shift_fnc = 2'bxx;
|
| 1864 |
|
|
muldiv_fnc = 3'bxxx;
|
| 1865 |
|
|
muldiv_start = 1'b0;
|
| 1866 |
|
|
sreg_we = 1'b0;
|
| 1867 |
|
|
psw_we = 1'b0;
|
| 1868 |
|
|
psw_new = 32'hxxxxxxxx;
|
| 1869 |
|
|
tlb_index_we = 1'b0;
|
| 1870 |
|
|
tlb_entry_hi_we = exc_tlb_any;
|
| 1871 |
|
|
tlb_entry_lo_we = 1'b0;
|
| 1872 |
|
|
mmu_bad_addr_we = exc_tlb_any;
|
| 1873 |
|
|
end
|
| 1874 |
|
|
default: // all other states: unused
|
| 1875 |
|
|
begin
|
| 1876 |
|
|
pc_src = 3'bxxx;
|
| 1877 |
|
|
pc_we = 1'bx;
|
| 1878 |
|
|
mar_we = 1'bx;
|
| 1879 |
|
|
ma_src = 1'bx;
|
| 1880 |
|
|
mmu_fnc = 3'bxxx;
|
| 1881 |
|
|
mdor_we = 1'bx;
|
| 1882 |
|
|
bus_stb = 1'bx;
|
| 1883 |
|
|
bus_we = 1'bx;
|
| 1884 |
|
|
bus_size = 2'bxx;
|
| 1885 |
|
|
mdir_we = 1'bx;
|
| 1886 |
|
|
mdir_sx = 1'bx;
|
| 1887 |
|
|
ir_we = 1'bx;
|
| 1888 |
|
|
reg_src2 = 2'bxx;
|
| 1889 |
|
|
reg_di2_src = 3'bxxx;
|
| 1890 |
|
|
reg_we2 = 1'bx;
|
| 1891 |
|
|
alu_src1 = 1'bx;
|
| 1892 |
|
|
alu_src2 = 3'bxxx;
|
| 1893 |
|
|
alu_fnc = 3'bxxx;
|
| 1894 |
|
|
shift_fnc = 2'bxx;
|
| 1895 |
|
|
muldiv_fnc = 3'bxxx;
|
| 1896 |
|
|
muldiv_start = 1'bx;
|
| 1897 |
|
|
sreg_we = 1'bx;
|
| 1898 |
|
|
psw_we = 1'bx;
|
| 1899 |
|
|
psw_new = 32'hxxxxxxxx;
|
| 1900 |
|
|
tlb_index_we = 1'bx;
|
| 1901 |
|
|
tlb_entry_hi_we = 1'bx;
|
| 1902 |
|
|
tlb_entry_lo_we = 1'bx;
|
| 1903 |
|
|
mmu_bad_addr_we = 1'bx;
|
| 1904 |
|
|
end
|
| 1905 |
|
|
endcase
|
| 1906 |
|
|
end
|
| 1907 |
|
|
|
| 1908 |
|
|
// branch logic
|
| 1909 |
|
|
always @(*) begin
|
| 1910 |
|
|
casex ( { opcode[3:0], alu_equ, alu_ult, alu_slt } )
|
| 1911 |
|
|
// eq
|
| 1912 |
|
|
7'b00000xx: branch = 0;
|
| 1913 |
|
|
7'b00001xx: branch = 1;
|
| 1914 |
|
|
// ne
|
| 1915 |
|
|
7'b00010xx: branch = 1;
|
| 1916 |
|
|
7'b00011xx: branch = 0;
|
| 1917 |
|
|
// le
|
| 1918 |
|
|
7'b00100x0: branch = 0;
|
| 1919 |
|
|
7'b00101xx: branch = 1;
|
| 1920 |
|
|
7'b0010xx1: branch = 1;
|
| 1921 |
|
|
// leu
|
| 1922 |
|
|
7'b001100x: branch = 0;
|
| 1923 |
|
|
7'b00111xx: branch = 1;
|
| 1924 |
|
|
7'b0011x1x: branch = 1;
|
| 1925 |
|
|
// lt
|
| 1926 |
|
|
7'b0100xx0: branch = 0;
|
| 1927 |
|
|
7'b0100xx1: branch = 1;
|
| 1928 |
|
|
// ltu
|
| 1929 |
|
|
7'b0101x0x: branch = 0;
|
| 1930 |
|
|
7'b0101x1x: branch = 1;
|
| 1931 |
|
|
// ge
|
| 1932 |
|
|
7'b0110xx0: branch = 1;
|
| 1933 |
|
|
7'b0110xx1: branch = 0;
|
| 1934 |
|
|
// geu
|
| 1935 |
|
|
7'b0111x0x: branch = 1;
|
| 1936 |
|
|
7'b0111x1x: branch = 0;
|
| 1937 |
|
|
// gt
|
| 1938 |
|
|
7'b10000x0: branch = 1;
|
| 1939 |
|
|
7'b10001xx: branch = 0;
|
| 1940 |
|
|
7'b1000xx1: branch = 0;
|
| 1941 |
|
|
// gtu
|
| 1942 |
|
|
7'b100100x: branch = 1;
|
| 1943 |
|
|
7'b10011xx: branch = 0;
|
| 1944 |
|
|
7'b1001x1x: branch = 0;
|
| 1945 |
|
|
// other
|
| 1946 |
|
|
default: branch = 1'bx;
|
| 1947 |
|
|
endcase
|
| 1948 |
|
|
end
|
| 1949 |
|
|
|
| 1950 |
|
|
// interrupts
|
| 1951 |
|
|
assign irq_pending = bus_irq[15:0] & psw[15:0];
|
| 1952 |
|
|
assign irq_trigger = (| irq_pending) & psw[23];
|
| 1953 |
|
|
always @(*) begin
|
| 1954 |
|
|
if ((| irq_pending[15:8]) != 0) begin
|
| 1955 |
|
|
if ((| irq_pending[15:12]) != 0) begin
|
| 1956 |
|
|
if ((| irq_pending[15:14]) != 0) begin
|
| 1957 |
|
|
if (irq_pending[15] != 0) begin
|
| 1958 |
|
|
irq_priority = 4'd15;
|
| 1959 |
|
|
end else begin
|
| 1960 |
|
|
irq_priority = 4'd14;
|
| 1961 |
|
|
end
|
| 1962 |
|
|
end else begin
|
| 1963 |
|
|
if (irq_pending[13] != 0) begin
|
| 1964 |
|
|
irq_priority = 4'd13;
|
| 1965 |
|
|
end else begin
|
| 1966 |
|
|
irq_priority = 4'd12;
|
| 1967 |
|
|
end
|
| 1968 |
|
|
end
|
| 1969 |
|
|
end else begin
|
| 1970 |
|
|
if ((| irq_pending[11:10]) != 0) begin
|
| 1971 |
|
|
if (irq_pending[11] != 0) begin
|
| 1972 |
|
|
irq_priority = 4'd11;
|
| 1973 |
|
|
end else begin
|
| 1974 |
|
|
irq_priority = 4'd10;
|
| 1975 |
|
|
end
|
| 1976 |
|
|
end else begin
|
| 1977 |
|
|
if (irq_pending[9] != 0) begin
|
| 1978 |
|
|
irq_priority = 4'd9;
|
| 1979 |
|
|
end else begin
|
| 1980 |
|
|
irq_priority = 4'd8;
|
| 1981 |
|
|
end
|
| 1982 |
|
|
end
|
| 1983 |
|
|
end
|
| 1984 |
|
|
end else begin
|
| 1985 |
|
|
if ((| irq_pending[7:4]) != 0) begin
|
| 1986 |
|
|
if ((| irq_pending[7:6]) != 0) begin
|
| 1987 |
|
|
if (irq_pending[7] != 0) begin
|
| 1988 |
|
|
irq_priority = 4'd7;
|
| 1989 |
|
|
end else begin
|
| 1990 |
|
|
irq_priority = 4'd6;
|
| 1991 |
|
|
end
|
| 1992 |
|
|
end else begin
|
| 1993 |
|
|
if (irq_pending[5] != 0) begin
|
| 1994 |
|
|
irq_priority = 4'd5;
|
| 1995 |
|
|
end else begin
|
| 1996 |
|
|
irq_priority = 4'd4;
|
| 1997 |
|
|
end
|
| 1998 |
|
|
end
|
| 1999 |
|
|
end else begin
|
| 2000 |
|
|
if ((| irq_pending[3:2]) != 0) begin
|
| 2001 |
|
|
if (irq_pending[3] != 0) begin
|
| 2002 |
|
|
irq_priority = 4'd3;
|
| 2003 |
|
|
end else begin
|
| 2004 |
|
|
irq_priority = 4'd2;
|
| 2005 |
|
|
end
|
| 2006 |
|
|
end else begin
|
| 2007 |
|
|
if (irq_pending[1] != 0) begin
|
| 2008 |
|
|
irq_priority = 4'd1;
|
| 2009 |
|
|
end else begin
|
| 2010 |
|
|
irq_priority = 4'd0;
|
| 2011 |
|
|
end
|
| 2012 |
|
|
end
|
| 2013 |
|
|
end
|
| 2014 |
|
|
end
|
| 2015 |
|
|
end
|
| 2016 |
|
|
|
| 2017 |
|
|
// exceptions
|
| 2018 |
|
|
assign exc_prv_addr = psw[26] & va_31;
|
| 2019 |
|
|
assign exc_ill_addr = (bus_size[0] & va_0) |
|
| 2020 |
|
|
(bus_size[1] & va_0) |
|
| 2021 |
|
|
(bus_size[1] & va_1);
|
| 2022 |
|
|
assign exc_tlb_but_wrtprot = tlb_kmissed | tlb_umissed | tlb_invalid;
|
| 2023 |
|
|
assign exc_tlb_any = exc_tlb_but_wrtprot | tlb_wrtprot;
|
| 2024 |
|
|
|
| 2025 |
|
|
endmodule
|
| 2026 |
|
|
|
| 2027 |
|
|
|
| 2028 |
|
|
//--------------------------------------------------------------
|
| 2029 |
|
|
// pc -- the program counter
|
| 2030 |
|
|
//--------------------------------------------------------------
|
| 2031 |
|
|
|
| 2032 |
|
|
|
| 2033 |
|
|
module pc(clk, pc_we, pc_next, pc);
|
| 2034 |
|
|
input clk;
|
| 2035 |
|
|
input pc_we;
|
| 2036 |
|
|
input [31:0] pc_next;
|
| 2037 |
|
|
output reg [31:0] pc;
|
| 2038 |
|
|
|
| 2039 |
|
|
always @(posedge clk) begin
|
| 2040 |
|
|
if (pc_we == 1) begin
|
| 2041 |
|
|
pc <= pc_next;
|
| 2042 |
|
|
end
|
| 2043 |
|
|
end
|
| 2044 |
|
|
|
| 2045 |
|
|
endmodule
|
| 2046 |
|
|
|
| 2047 |
|
|
|
| 2048 |
|
|
//--------------------------------------------------------------
|
| 2049 |
|
|
// mar -- the memory address register
|
| 2050 |
|
|
//--------------------------------------------------------------
|
| 2051 |
|
|
|
| 2052 |
|
|
|
| 2053 |
|
|
module mar(clk, mar_we, mar_next, mar);
|
| 2054 |
|
|
input clk;
|
| 2055 |
|
|
input mar_we;
|
| 2056 |
|
|
input [31:0] mar_next;
|
| 2057 |
|
|
output reg [31:0] mar;
|
| 2058 |
|
|
|
| 2059 |
|
|
always @(posedge clk) begin
|
| 2060 |
|
|
if (mar_we == 1) begin
|
| 2061 |
|
|
mar <= mar_next;
|
| 2062 |
|
|
end
|
| 2063 |
|
|
end
|
| 2064 |
|
|
|
| 2065 |
|
|
endmodule
|
| 2066 |
|
|
|
| 2067 |
|
|
|
| 2068 |
|
|
//--------------------------------------------------------------
|
| 2069 |
|
|
// mdor -- the memory data out register
|
| 2070 |
|
|
//--------------------------------------------------------------
|
| 2071 |
|
|
|
| 2072 |
|
|
|
| 2073 |
|
|
module mdor(clk, mdor_we, mdor_next, mdor);
|
| 2074 |
|
|
input clk;
|
| 2075 |
|
|
input mdor_we;
|
| 2076 |
|
|
input [31:0] mdor_next;
|
| 2077 |
|
|
output reg [31:0] mdor;
|
| 2078 |
|
|
|
| 2079 |
|
|
always @(posedge clk) begin
|
| 2080 |
|
|
if (mdor_we == 1) begin
|
| 2081 |
|
|
mdor <= mdor_next;
|
| 2082 |
|
|
end
|
| 2083 |
|
|
end
|
| 2084 |
|
|
|
| 2085 |
|
|
endmodule
|
| 2086 |
|
|
|
| 2087 |
|
|
|
| 2088 |
|
|
//--------------------------------------------------------------
|
| 2089 |
|
|
// mdir -- the memory data in register
|
| 2090 |
|
|
//--------------------------------------------------------------
|
| 2091 |
|
|
|
| 2092 |
|
|
|
| 2093 |
|
|
module mdir(clk, mdir_we, mdir_next, size, sx, mdir);
|
| 2094 |
|
|
input clk;
|
| 2095 |
|
|
input mdir_we;
|
| 2096 |
|
|
input [31:0] mdir_next;
|
| 2097 |
|
|
input [1:0] size;
|
| 2098 |
|
|
input sx;
|
| 2099 |
|
|
output reg [31:0] mdir;
|
| 2100 |
|
|
|
| 2101 |
|
|
reg [31:0] data;
|
| 2102 |
|
|
|
| 2103 |
|
|
always @(posedge clk) begin
|
| 2104 |
|
|
if (mdir_we == 1) begin
|
| 2105 |
|
|
data <= mdir_next;
|
| 2106 |
|
|
end
|
| 2107 |
|
|
end
|
| 2108 |
|
|
|
| 2109 |
|
|
always @(*) begin
|
| 2110 |
|
|
case ({ size, sx })
|
| 2111 |
|
|
3'b000:
|
| 2112 |
|
|
begin
|
| 2113 |
|
|
mdir[31:0] = { 24'h000000, data[7:0] };
|
| 2114 |
|
|
end
|
| 2115 |
|
|
3'b001:
|
| 2116 |
|
|
begin
|
| 2117 |
|
|
if (data[7] == 1) begin
|
| 2118 |
|
|
mdir[31:0] = { 24'hFFFFFF, data[7:0] };
|
| 2119 |
|
|
end else begin
|
| 2120 |
|
|
mdir[31:0] = { 24'h000000, data[7:0] };
|
| 2121 |
|
|
end
|
| 2122 |
|
|
end
|
| 2123 |
|
|
3'b010:
|
| 2124 |
|
|
begin
|
| 2125 |
|
|
mdir[31:0] = { 16'h0000, data[15:0] };
|
| 2126 |
|
|
end
|
| 2127 |
|
|
3'b011:
|
| 2128 |
|
|
begin
|
| 2129 |
|
|
if (data[15] == 1) begin
|
| 2130 |
|
|
mdir[31:0] = { 16'hFFFF, data[15:0] };
|
| 2131 |
|
|
end else begin
|
| 2132 |
|
|
mdir[31:0] = { 16'h0000, data[15:0] };
|
| 2133 |
|
|
end
|
| 2134 |
|
|
end
|
| 2135 |
|
|
default:
|
| 2136 |
|
|
begin
|
| 2137 |
|
|
mdir[31:0] = data[31:0];
|
| 2138 |
|
|
end
|
| 2139 |
|
|
endcase
|
| 2140 |
|
|
end
|
| 2141 |
|
|
|
| 2142 |
|
|
endmodule
|
| 2143 |
|
|
|
| 2144 |
|
|
|
| 2145 |
|
|
//--------------------------------------------------------------
|
| 2146 |
|
|
// ir -- the instruction register and decoder
|
| 2147 |
|
|
//--------------------------------------------------------------
|
| 2148 |
|
|
|
| 2149 |
|
|
|
| 2150 |
|
|
module ir(clk,
|
| 2151 |
|
|
ir_we, instr,
|
| 2152 |
|
|
opcode, reg1, reg2, reg3,
|
| 2153 |
|
|
sx16, zx16, hi16, sx16s2, sx26s2);
|
| 2154 |
|
|
input clk;
|
| 2155 |
|
|
input ir_we;
|
| 2156 |
|
|
input [31:0] instr;
|
| 2157 |
|
|
output [5:0] opcode;
|
| 2158 |
|
|
output [4:0] reg1;
|
| 2159 |
|
|
output [4:0] reg2;
|
| 2160 |
|
|
output [4:0] reg3;
|
| 2161 |
|
|
output [31:0] sx16;
|
| 2162 |
|
|
output [31:0] zx16;
|
| 2163 |
|
|
output [31:0] hi16;
|
| 2164 |
|
|
output [31:0] sx16s2;
|
| 2165 |
|
|
output [31:0] sx26s2;
|
| 2166 |
|
|
|
| 2167 |
|
|
reg [31:0] ir;
|
| 2168 |
|
|
wire [15:0] copy_sign_16; // 16-bit copy of a 16-bit immediate's sign
|
| 2169 |
|
|
wire [3:0] copy_sign_26; // 4-bit copy of a 26-bit immediate's sign
|
| 2170 |
|
|
|
| 2171 |
|
|
always @(posedge clk) begin
|
| 2172 |
|
|
if (ir_we) begin
|
| 2173 |
|
|
ir <= instr;
|
| 2174 |
|
|
end
|
| 2175 |
|
|
end
|
| 2176 |
|
|
|
| 2177 |
|
|
assign opcode[5:0] = ir[31:26];
|
| 2178 |
|
|
assign reg1[4:0] = ir[25:21];
|
| 2179 |
|
|
assign reg2[4:0] = ir[20:16];
|
| 2180 |
|
|
assign reg3[4:0] = ir[15:11];
|
| 2181 |
|
|
assign copy_sign_16[15:0] = (ir[15] == 1) ? 16'hFFFF : 16'h0000;
|
| 2182 |
|
|
assign copy_sign_26[3:0] = (ir[25] == 1) ? 4'hF : 4'h0;
|
| 2183 |
|
|
assign sx16[31:0] = { copy_sign_16[15:0], ir[15:0] };
|
| 2184 |
|
|
assign zx16[31:0] = { 16'h0000, ir[15:0] };
|
| 2185 |
|
|
assign hi16[31:0] = { ir[15:0], 16'h0000 };
|
| 2186 |
|
|
assign sx16s2[31:0] = { copy_sign_16[13:0], ir[15:0], 2'b00 };
|
| 2187 |
|
|
assign sx26s2[31:0] = { copy_sign_26[3:0], ir[25:0], 2'b00 };
|
| 2188 |
|
|
|
| 2189 |
|
|
endmodule
|
| 2190 |
|
|
|
| 2191 |
|
|
|
| 2192 |
|
|
//--------------------------------------------------------------
|
| 2193 |
|
|
// regs -- the register file
|
| 2194 |
|
|
//--------------------------------------------------------------
|
| 2195 |
|
|
|
| 2196 |
|
|
|
| 2197 |
|
|
module regs(clk,
|
| 2198 |
|
|
rn1, do1,
|
| 2199 |
|
|
rn2, do2, we2, di2);
|
| 2200 |
|
|
input clk;
|
| 2201 |
|
|
input [4:0] rn1;
|
| 2202 |
|
|
output reg [31:0] do1;
|
| 2203 |
|
|
input [4:0] rn2;
|
| 2204 |
|
|
output reg [31:0] do2;
|
| 2205 |
|
|
input we2;
|
| 2206 |
|
|
input [31:0] di2;
|
| 2207 |
|
|
|
| 2208 |
|
|
reg [31:0] r[0:31];
|
| 2209 |
|
|
|
| 2210 |
|
|
always @(posedge clk) begin
|
| 2211 |
|
|
do1 <= r[rn1];
|
| 2212 |
|
|
if (we2 == 0) begin
|
| 2213 |
|
|
do2 <= r[rn2];
|
| 2214 |
|
|
end else begin
|
| 2215 |
|
|
do2 <= di2;
|
| 2216 |
|
|
r[rn2] <= di2;
|
| 2217 |
|
|
end
|
| 2218 |
|
|
end
|
| 2219 |
|
|
|
| 2220 |
|
|
endmodule
|
| 2221 |
|
|
|
| 2222 |
|
|
|
| 2223 |
|
|
//--------------------------------------------------------------
|
| 2224 |
|
|
// alu -- the arithmetic/logic unit
|
| 2225 |
|
|
//--------------------------------------------------------------
|
| 2226 |
|
|
|
| 2227 |
|
|
|
| 2228 |
|
|
module alu(a, b, fnc,
|
| 2229 |
|
|
res, equ, ult, slt);
|
| 2230 |
|
|
input [31:0] a;
|
| 2231 |
|
|
input [31:0] b;
|
| 2232 |
|
|
input [2:0] fnc;
|
| 2233 |
|
|
output [31:0] res;
|
| 2234 |
|
|
output equ;
|
| 2235 |
|
|
output ult;
|
| 2236 |
|
|
output slt;
|
| 2237 |
|
|
|
| 2238 |
|
|
wire [32:0] a1;
|
| 2239 |
|
|
wire [32:0] b1;
|
| 2240 |
|
|
reg [32:0] res1;
|
| 2241 |
|
|
|
| 2242 |
|
|
assign a1 = { 1'b0, a };
|
| 2243 |
|
|
assign b1 = { 1'b0, b };
|
| 2244 |
|
|
|
| 2245 |
|
|
always @(*) begin
|
| 2246 |
|
|
case (fnc)
|
| 2247 |
|
|
3'b000: res1 = a1 + b1;
|
| 2248 |
|
|
3'b001: res1 = a1 - b1;
|
| 2249 |
|
|
3'b010: res1 = a1;
|
| 2250 |
|
|
3'b011: res1 = b1;
|
| 2251 |
|
|
3'b100: res1 = a1 & b1;
|
| 2252 |
|
|
3'b101: res1 = a1 | b1;
|
| 2253 |
|
|
3'b110: res1 = a1 ^ b1;
|
| 2254 |
|
|
3'b111: res1 = a1 ~^ b1;
|
| 2255 |
|
|
default: res1 = 33'hxxxxxxxx;
|
| 2256 |
|
|
endcase
|
| 2257 |
|
|
end
|
| 2258 |
|
|
|
| 2259 |
|
|
assign res = res1[31:0];
|
| 2260 |
|
|
assign equ = ~| res1[31:0];
|
| 2261 |
|
|
assign ult = res1[32];
|
| 2262 |
|
|
assign slt = res1[32] ^ a[31] ^ b[31];
|
| 2263 |
|
|
|
| 2264 |
|
|
endmodule
|
| 2265 |
|
|
|
| 2266 |
|
|
|
| 2267 |
|
|
//--------------------------------------------------------------
|
| 2268 |
|
|
// shift -- the shift unit
|
| 2269 |
|
|
//--------------------------------------------------------------
|
| 2270 |
|
|
|
| 2271 |
|
|
|
| 2272 |
|
|
module shift(clk, data_in, shamt, fnc, data_out);
|
| 2273 |
|
|
input clk;
|
| 2274 |
|
|
input [31:0] data_in;
|
| 2275 |
|
|
input [4:0] shamt;
|
| 2276 |
|
|
input [1:0] fnc;
|
| 2277 |
|
|
output reg [31:0] data_out;
|
| 2278 |
|
|
|
| 2279 |
|
|
always @(posedge clk) begin
|
| 2280 |
|
|
if (fnc == 2'b00) begin
|
| 2281 |
|
|
// sll
|
| 2282 |
|
|
data_out <= data_in << shamt;
|
| 2283 |
|
|
end else
|
| 2284 |
|
|
if (fnc == 2'b01) begin
|
| 2285 |
|
|
// slr
|
| 2286 |
|
|
data_out <= data_in >> shamt;
|
| 2287 |
|
|
end else
|
| 2288 |
|
|
if (fnc == 2'b10) begin
|
| 2289 |
|
|
// sar
|
| 2290 |
|
|
if (data_in[31] == 1) begin
|
| 2291 |
|
|
data_out <= ~(32'hFFFFFFFF >> shamt) |
|
| 2292 |
|
|
(data_in >> shamt);
|
| 2293 |
|
|
end else begin
|
| 2294 |
|
|
data_out <= data_in >> shamt;
|
| 2295 |
|
|
end
|
| 2296 |
|
|
end else begin
|
| 2297 |
|
|
data_out <= 32'hxxxxxxxx;
|
| 2298 |
|
|
end
|
| 2299 |
|
|
end
|
| 2300 |
|
|
|
| 2301 |
|
|
endmodule
|
| 2302 |
|
|
|
| 2303 |
|
|
|
| 2304 |
|
|
//--------------------------------------------------------------
|
| 2305 |
|
|
// muldiv -- the multiplier/divide unit
|
| 2306 |
|
|
//--------------------------------------------------------------
|
| 2307 |
|
|
|
| 2308 |
|
|
|
| 2309 |
|
|
module muldiv(clk, a, b, fnc, start, done, error, res);
|
| 2310 |
|
|
input clk;
|
| 2311 |
|
|
input [31:0] a;
|
| 2312 |
|
|
input [31:0] b;
|
| 2313 |
|
|
input [2:0] fnc;
|
| 2314 |
|
|
input start;
|
| 2315 |
|
|
output reg done;
|
| 2316 |
|
|
output reg error;
|
| 2317 |
|
|
output reg [31:0] res;
|
| 2318 |
|
|
|
| 2319 |
|
|
// fnc = 000 op = undefined
|
| 2320 |
|
|
// 001 undefined
|
| 2321 |
|
|
// 010 mul
|
| 2322 |
|
|
// 011 mulu
|
| 2323 |
|
|
// 100 div
|
| 2324 |
|
|
// 101 divu
|
| 2325 |
|
|
// 110 rem
|
| 2326 |
|
|
// 111 remu
|
| 2327 |
|
|
|
| 2328 |
|
|
reg div;
|
| 2329 |
|
|
reg rem;
|
| 2330 |
|
|
reg [5:0] count;
|
| 2331 |
|
|
reg a_neg;
|
| 2332 |
|
|
reg b_neg;
|
| 2333 |
|
|
reg [31:0] b_abs;
|
| 2334 |
|
|
reg [64:0] q;
|
| 2335 |
|
|
wire [64:1] s;
|
| 2336 |
|
|
wire [64:0] d;
|
| 2337 |
|
|
|
| 2338 |
|
|
assign s[64:32] = q[64:32] + { 1'b0, b_abs };
|
| 2339 |
|
|
assign s[31: 1] = q[31: 1];
|
| 2340 |
|
|
assign d[64:32] = q[64:32] - { 1'b0, b_abs };
|
| 2341 |
|
|
assign d[31: 0] = q[31: 0];
|
| 2342 |
|
|
|
| 2343 |
|
|
always @(posedge clk) begin
|
| 2344 |
|
|
if (start == 1) begin
|
| 2345 |
|
|
if (fnc[2] == 1 && (| b[31:0]) == 0) begin
|
| 2346 |
|
|
// division by zero
|
| 2347 |
|
|
done <= 1;
|
| 2348 |
|
|
error <= 1;
|
| 2349 |
|
|
end else begin
|
| 2350 |
|
|
// operands are ok
|
| 2351 |
|
|
done <= 0;
|
| 2352 |
|
|
error <= 0;
|
| 2353 |
|
|
end
|
| 2354 |
|
|
div <= fnc[2];
|
| 2355 |
|
|
rem <= fnc[1];
|
| 2356 |
|
|
count <= 6'd0;
|
| 2357 |
|
|
if (fnc[0] == 0 && a[31] == 1) begin
|
| 2358 |
|
|
// negate first operand
|
| 2359 |
|
|
a_neg <= 1;
|
| 2360 |
|
|
if (fnc[2] == 0) begin
|
| 2361 |
|
|
// initialize q for multiplication
|
| 2362 |
|
|
q[64:32] <= 33'b0;
|
| 2363 |
|
|
q[31: 0] <= ~a + 1;
|
| 2364 |
|
|
end else begin
|
| 2365 |
|
|
// initialize q for division and remainder
|
| 2366 |
|
|
q[64:33] <= 32'b0;
|
| 2367 |
|
|
q[32: 1] <= ~a + 1;
|
| 2368 |
|
|
q[ 0: 0] <= 1'b0;
|
| 2369 |
|
|
end
|
| 2370 |
|
|
end else begin
|
| 2371 |
|
|
// use first operand as is
|
| 2372 |
|
|
a_neg <= 0;
|
| 2373 |
|
|
if (fnc[2] == 0) begin
|
| 2374 |
|
|
// initialize q for multiplication
|
| 2375 |
|
|
q[64:32] <= 33'b0;
|
| 2376 |
|
|
q[31: 0] <= a;
|
| 2377 |
|
|
end else begin
|
| 2378 |
|
|
// initialize q for division and remainder
|
| 2379 |
|
|
q[64:33] <= 32'b0;
|
| 2380 |
|
|
q[32: 1] <= a;
|
| 2381 |
|
|
q[ 0: 0] <= 1'b0;
|
| 2382 |
|
|
end
|
| 2383 |
|
|
end
|
| 2384 |
|
|
if (fnc[0] == 0 && b[31] == 1) begin
|
| 2385 |
|
|
// negate second operand
|
| 2386 |
|
|
b_neg <= 1;
|
| 2387 |
|
|
b_abs <= ~b + 1;
|
| 2388 |
|
|
end else begin
|
| 2389 |
|
|
// use second operand as is
|
| 2390 |
|
|
b_neg <= 0;
|
| 2391 |
|
|
b_abs <= b;
|
| 2392 |
|
|
end
|
| 2393 |
|
|
end else begin
|
| 2394 |
|
|
if (done == 0) begin
|
| 2395 |
|
|
// algorithm not yet finished
|
| 2396 |
|
|
if (div == 0) begin
|
| 2397 |
|
|
//
|
| 2398 |
|
|
// multiplication
|
| 2399 |
|
|
//
|
| 2400 |
|
|
if (count == 6'd32) begin
|
| 2401 |
|
|
// last step
|
| 2402 |
|
|
done <= 1;
|
| 2403 |
|
|
if (a_neg == b_neg) begin
|
| 2404 |
|
|
res <= q[31:0];
|
| 2405 |
|
|
end else begin
|
| 2406 |
|
|
res <= ~q[31:0] + 1;
|
| 2407 |
|
|
end
|
| 2408 |
|
|
end else begin
|
| 2409 |
|
|
// all other steps
|
| 2410 |
|
|
count <= count + 1;
|
| 2411 |
|
|
if (q[0] == 1) begin
|
| 2412 |
|
|
q <= { 1'b0, s[64:1] };
|
| 2413 |
|
|
end else begin
|
| 2414 |
|
|
q <= { 1'b0, q[64:1] };
|
| 2415 |
|
|
end
|
| 2416 |
|
|
end
|
| 2417 |
|
|
end else begin
|
| 2418 |
|
|
//
|
| 2419 |
|
|
// division and remainder
|
| 2420 |
|
|
//
|
| 2421 |
|
|
if (count == 6'd32) begin
|
| 2422 |
|
|
// last step
|
| 2423 |
|
|
done <= 1;
|
| 2424 |
|
|
if (rem == 0) begin
|
| 2425 |
|
|
// result <= quotient
|
| 2426 |
|
|
if (a_neg == b_neg) begin
|
| 2427 |
|
|
res <= q[31:0];
|
| 2428 |
|
|
end else begin
|
| 2429 |
|
|
res <= ~q[31:0] + 1;
|
| 2430 |
|
|
end
|
| 2431 |
|
|
end else begin
|
| 2432 |
|
|
// result <= remainder
|
| 2433 |
|
|
if (a_neg == 0) begin
|
| 2434 |
|
|
res <= q[64:33];
|
| 2435 |
|
|
end else begin
|
| 2436 |
|
|
res <= ~q[64:33] + 1;
|
| 2437 |
|
|
end
|
| 2438 |
|
|
end
|
| 2439 |
|
|
end else begin
|
| 2440 |
|
|
// all other steps
|
| 2441 |
|
|
count <= count + 1;
|
| 2442 |
|
|
if (d[64] == 0) begin
|
| 2443 |
|
|
q <= { d[63:0], 1'b1 };
|
| 2444 |
|
|
end else begin
|
| 2445 |
|
|
q <= { q[63:0], 1'b0 };
|
| 2446 |
|
|
end
|
| 2447 |
|
|
end
|
| 2448 |
|
|
end
|
| 2449 |
|
|
end
|
| 2450 |
|
|
end
|
| 2451 |
|
|
end
|
| 2452 |
|
|
|
| 2453 |
|
|
endmodule
|
| 2454 |
|
|
|
| 2455 |
|
|
|
| 2456 |
|
|
//--------------------------------------------------------------
|
| 2457 |
|
|
// sregs -- the special registers
|
| 2458 |
|
|
//--------------------------------------------------------------
|
| 2459 |
|
|
|
| 2460 |
|
|
|
| 2461 |
|
|
module sregs(clk, rst,
|
| 2462 |
|
|
rn, we, din, dout,
|
| 2463 |
|
|
psw, psw_we, psw_new,
|
| 2464 |
|
|
tlb_index, tlb_index_we, tlb_index_new,
|
| 2465 |
|
|
tlb_entry_hi, tlb_entry_hi_we, tlb_entry_hi_new,
|
| 2466 |
|
|
tlb_entry_lo, tlb_entry_lo_we, tlb_entry_lo_new,
|
| 2467 |
|
|
mmu_bad_addr, mmu_bad_addr_we, mmu_bad_addr_new,
|
| 2468 |
|
|
mmu_bad_accs, mmu_bad_accs_we, mmu_bad_accs_new);
|
| 2469 |
|
|
input clk;
|
| 2470 |
|
|
input rst;
|
| 2471 |
|
|
input [2:0] rn;
|
| 2472 |
|
|
input we;
|
| 2473 |
|
|
input [31:0] din;
|
| 2474 |
|
|
output [31:0] dout;
|
| 2475 |
|
|
output [31:0] psw;
|
| 2476 |
|
|
input psw_we;
|
| 2477 |
|
|
input [31:0] psw_new;
|
| 2478 |
|
|
output [31:0] tlb_index;
|
| 2479 |
|
|
input tlb_index_we;
|
| 2480 |
|
|
input [31:0] tlb_index_new;
|
| 2481 |
|
|
output [31:0] tlb_entry_hi;
|
| 2482 |
|
|
input tlb_entry_hi_we;
|
| 2483 |
|
|
input [31:0] tlb_entry_hi_new;
|
| 2484 |
|
|
output [31:0] tlb_entry_lo;
|
| 2485 |
|
|
input tlb_entry_lo_we;
|
| 2486 |
|
|
input [31:0] tlb_entry_lo_new;
|
| 2487 |
|
|
output [31:0] mmu_bad_addr;
|
| 2488 |
|
|
input mmu_bad_addr_we;
|
| 2489 |
|
|
input [31:0] mmu_bad_addr_new;
|
| 2490 |
|
|
output [31:0] mmu_bad_accs;
|
| 2491 |
|
|
input mmu_bad_accs_we;
|
| 2492 |
|
|
input [31:0] mmu_bad_accs_new;
|
| 2493 |
|
|
|
| 2494 |
|
|
// rn = 000 register = PSW
|
| 2495 |
|
|
// 001 TLB index
|
| 2496 |
|
|
// 010 TLB entry high
|
| 2497 |
|
|
// 011 TLB entry low
|
| 2498 |
|
|
// 100 MMU bad address
|
| 2499 |
|
|
// 101 MMU bad access
|
| 2500 |
|
|
// 110 - not used -
|
| 2501 |
|
|
// 111 - not used -
|
| 2502 |
|
|
|
| 2503 |
|
|
reg [31:0] sr[0:7];
|
| 2504 |
|
|
|
| 2505 |
|
|
assign dout = sr[rn];
|
| 2506 |
|
|
assign psw = sr[0];
|
| 2507 |
|
|
assign tlb_index = sr[1];
|
| 2508 |
|
|
assign tlb_entry_hi = sr[2];
|
| 2509 |
|
|
assign tlb_entry_lo = sr[3];
|
| 2510 |
|
|
assign mmu_bad_addr = sr[4];
|
| 2511 |
|
|
assign mmu_bad_accs = sr[5];
|
| 2512 |
|
|
|
| 2513 |
|
|
always @(posedge clk) begin
|
| 2514 |
|
|
if (rst == 1) begin
|
| 2515 |
|
|
sr[0] <= 32'h00000000;
|
| 2516 |
|
|
end else begin
|
| 2517 |
|
|
if (we == 1) begin
|
| 2518 |
|
|
sr[rn] <= din;
|
| 2519 |
|
|
end else begin
|
| 2520 |
|
|
if (psw_we) begin
|
| 2521 |
|
|
sr[0] <= psw_new;
|
| 2522 |
|
|
end
|
| 2523 |
|
|
if (tlb_index_we) begin
|
| 2524 |
|
|
sr[1] <= tlb_index_new;
|
| 2525 |
|
|
end
|
| 2526 |
|
|
if (tlb_entry_hi_we) begin
|
| 2527 |
|
|
sr[2] <= tlb_entry_hi_new;
|
| 2528 |
|
|
end
|
| 2529 |
|
|
if (tlb_entry_lo_we) begin
|
| 2530 |
|
|
sr[3] <= tlb_entry_lo_new;
|
| 2531 |
|
|
end
|
| 2532 |
|
|
if (mmu_bad_addr_we) begin
|
| 2533 |
|
|
sr[4] <= mmu_bad_addr_new;
|
| 2534 |
|
|
end
|
| 2535 |
|
|
if (mmu_bad_accs_we) begin
|
| 2536 |
|
|
sr[5] <= mmu_bad_accs_new;
|
| 2537 |
|
|
end
|
| 2538 |
|
|
end
|
| 2539 |
|
|
end
|
| 2540 |
|
|
end
|
| 2541 |
|
|
|
| 2542 |
|
|
endmodule
|
| 2543 |
|
|
|
| 2544 |
|
|
|
| 2545 |
|
|
//--------------------------------------------------------------
|
| 2546 |
|
|
// mmu -- the memory management unit
|
| 2547 |
|
|
//--------------------------------------------------------------
|
| 2548 |
|
|
|
| 2549 |
|
|
|
| 2550 |
|
|
module mmu(clk, rst, fnc, virt, phys,
|
| 2551 |
|
|
tlb_index, tlb_index_new,
|
| 2552 |
|
|
tlb_entry_hi, tlb_entry_hi_new,
|
| 2553 |
|
|
tlb_entry_lo, tlb_entry_lo_new,
|
| 2554 |
|
|
tlb_kmissed, tlb_umissed,
|
| 2555 |
|
|
tlb_invalid, tlb_wrtprot);
|
| 2556 |
|
|
input clk;
|
| 2557 |
|
|
input rst;
|
| 2558 |
|
|
input [2:0] fnc;
|
| 2559 |
|
|
input [31:0] virt;
|
| 2560 |
|
|
output [31:0] phys;
|
| 2561 |
|
|
input [31:0] tlb_index;
|
| 2562 |
|
|
output [31:0] tlb_index_new;
|
| 2563 |
|
|
input [31:0] tlb_entry_hi;
|
| 2564 |
|
|
output [31:0] tlb_entry_hi_new;
|
| 2565 |
|
|
input [31:0] tlb_entry_lo;
|
| 2566 |
|
|
output [31:0] tlb_entry_lo_new;
|
| 2567 |
|
|
output tlb_kmissed;
|
| 2568 |
|
|
output tlb_umissed;
|
| 2569 |
|
|
output tlb_invalid;
|
| 2570 |
|
|
output tlb_wrtprot;
|
| 2571 |
|
|
|
| 2572 |
|
|
// fnc = 000 no operation, hold output
|
| 2573 |
|
|
// 001 map virt to phys address
|
| 2574 |
|
|
// 010 tbs
|
| 2575 |
|
|
// 011 tbwr
|
| 2576 |
|
|
// 100 tbri
|
| 2577 |
|
|
// 101 tbwi
|
| 2578 |
|
|
// 110 undefined
|
| 2579 |
|
|
// 111 undefined
|
| 2580 |
|
|
|
| 2581 |
|
|
wire map;
|
| 2582 |
|
|
wire tbs;
|
| 2583 |
|
|
wire tbwr;
|
| 2584 |
|
|
wire tbri;
|
| 2585 |
|
|
wire tbwi;
|
| 2586 |
|
|
reg [19:0] page;
|
| 2587 |
|
|
reg [11:0] offset;
|
| 2588 |
|
|
wire [19:0] tlb_page;
|
| 2589 |
|
|
wire tlb_miss;
|
| 2590 |
|
|
wire [4:0] tlb_found;
|
| 2591 |
|
|
wire tlb_enable;
|
| 2592 |
|
|
wire [19:0] tlb_frame;
|
| 2593 |
|
|
wire tlb_wbit;
|
| 2594 |
|
|
wire tlb_vbit;
|
| 2595 |
|
|
wire [4:0] rw_index;
|
| 2596 |
|
|
wire [19:0] r_page;
|
| 2597 |
|
|
wire [19:0] r_frame;
|
| 2598 |
|
|
wire w_enable;
|
| 2599 |
|
|
wire [19:0] w_page;
|
| 2600 |
|
|
wire [19:0] w_frame;
|
| 2601 |
|
|
wire direct;
|
| 2602 |
|
|
wire [17:0] frame;
|
| 2603 |
|
|
reg [4:0] random_index;
|
| 2604 |
|
|
reg tlb_miss_delayed;
|
| 2605 |
|
|
|
| 2606 |
|
|
// decode function
|
| 2607 |
|
|
assign map = (fnc == 3'b001) ? 1 : 0;
|
| 2608 |
|
|
assign tbs = (fnc == 3'b010) ? 1 : 0;
|
| 2609 |
|
|
assign tbwr = (fnc == 3'b011) ? 1 : 0;
|
| 2610 |
|
|
assign tbri = (fnc == 3'b100) ? 1 : 0;
|
| 2611 |
|
|
assign tbwi = (fnc == 3'b101) ? 1 : 0;
|
| 2612 |
|
|
|
| 2613 |
|
|
// latch virtual address
|
| 2614 |
|
|
always @(posedge clk) begin
|
| 2615 |
|
|
if (map == 1) begin
|
| 2616 |
|
|
page <= virt[31:12];
|
| 2617 |
|
|
offset <= virt[11:0];
|
| 2618 |
|
|
end
|
| 2619 |
|
|
end
|
| 2620 |
|
|
|
| 2621 |
|
|
// create tlb instance
|
| 2622 |
|
|
assign tlb_page = (tbs == 1) ? tlb_entry_hi[31:12] : virt[31:12];
|
| 2623 |
|
|
assign tlb_enable = map;
|
| 2624 |
|
|
assign tlb_wbit = tlb_frame[1];
|
| 2625 |
|
|
assign tlb_vbit = tlb_frame[0];
|
| 2626 |
|
|
assign rw_index = (tbwr == 1) ? random_index : tlb_index[4:0];
|
| 2627 |
|
|
assign tlb_index_new = { tlb_miss, 26'b0, tlb_found };
|
| 2628 |
|
|
assign tlb_entry_hi_new = { ((tbri == 1) ? r_page : page),
|
| 2629 |
|
|
tlb_entry_hi[11:0] };
|
| 2630 |
|
|
assign tlb_entry_lo_new = { tlb_entry_lo[31:30], r_frame[19:2],
|
| 2631 |
|
|
tlb_entry_lo[11:2], r_frame[1:0] };
|
| 2632 |
|
|
assign w_enable = tbwr | tbwi;
|
| 2633 |
|
|
assign w_page = tlb_entry_hi[31:12];
|
| 2634 |
|
|
assign w_frame = { tlb_entry_lo[29:12], tlb_entry_lo[1:0] };
|
| 2635 |
|
|
tlb tlb_1(tlb_page, tlb_miss, tlb_found,
|
| 2636 |
|
|
clk, tlb_enable, tlb_frame,
|
| 2637 |
|
|
rw_index, r_page, r_frame,
|
| 2638 |
|
|
w_enable, w_page, w_frame);
|
| 2639 |
|
|
|
| 2640 |
|
|
// construct physical address
|
| 2641 |
|
|
assign direct = (page[19:18] == 2'b11) ? 1 : 0;
|
| 2642 |
|
|
assign frame = (direct == 1) ? page[17:0] : tlb_frame[19:2];
|
| 2643 |
|
|
assign phys = { 2'b00, frame, offset };
|
| 2644 |
|
|
|
| 2645 |
|
|
// generate "random" index
|
| 2646 |
|
|
always @(posedge clk) begin
|
| 2647 |
|
|
if (rst == 1) begin
|
| 2648 |
|
|
// the index register is counting down
|
| 2649 |
|
|
// so we must start at topmost index
|
| 2650 |
|
|
random_index <= 5'd31;
|
| 2651 |
|
|
end else begin
|
| 2652 |
|
|
// decrement index register "randomly"
|
| 2653 |
|
|
// (whenever there is a mapping operation)
|
| 2654 |
|
|
// skip "fixed" entries (0..3)
|
| 2655 |
|
|
if (map == 1) begin
|
| 2656 |
|
|
if (random_index == 5'd4) begin
|
| 2657 |
|
|
random_index <= 5'd31;
|
| 2658 |
|
|
end else begin
|
| 2659 |
|
|
random_index <= random_index - 1;
|
| 2660 |
|
|
end
|
| 2661 |
|
|
end
|
| 2662 |
|
|
end
|
| 2663 |
|
|
end
|
| 2664 |
|
|
|
| 2665 |
|
|
// generate TLB exceptions
|
| 2666 |
|
|
always @(posedge clk) begin
|
| 2667 |
|
|
if (map == 1) begin
|
| 2668 |
|
|
tlb_miss_delayed <= tlb_miss;
|
| 2669 |
|
|
end
|
| 2670 |
|
|
end
|
| 2671 |
|
|
assign tlb_kmissed = tlb_miss_delayed & ~direct & page[19];
|
| 2672 |
|
|
assign tlb_umissed = tlb_miss_delayed & ~direct & ~page[19];
|
| 2673 |
|
|
assign tlb_invalid = ~tlb_vbit & ~direct;
|
| 2674 |
|
|
assign tlb_wrtprot = ~tlb_wbit & ~direct;
|
| 2675 |
|
|
|
| 2676 |
|
|
endmodule
|
| 2677 |
|
|
|
| 2678 |
|
|
|
| 2679 |
|
|
//--------------------------------------------------------------
|
| 2680 |
|
|
// tlb -- the translation lookaside buffer
|
| 2681 |
|
|
//--------------------------------------------------------------
|
| 2682 |
|
|
|
| 2683 |
|
|
|
| 2684 |
|
|
module tlb(page_in, miss, found,
|
| 2685 |
|
|
clk, enable, frame_out,
|
| 2686 |
|
|
rw_index, r_page, r_frame,
|
| 2687 |
|
|
w_enable, w_page, w_frame);
|
| 2688 |
|
|
input [19:0] page_in;
|
| 2689 |
|
|
output miss;
|
| 2690 |
|
|
output [4:0] found;
|
| 2691 |
|
|
input clk;
|
| 2692 |
|
|
input enable;
|
| 2693 |
|
|
output reg [19:0] frame_out;
|
| 2694 |
|
|
input [4:0] rw_index;
|
| 2695 |
|
|
output reg [19:0] r_page;
|
| 2696 |
|
|
output reg [19:0] r_frame;
|
| 2697 |
|
|
input w_enable;
|
| 2698 |
|
|
input [19:0] w_page;
|
| 2699 |
|
|
input [19:0] w_frame;
|
| 2700 |
|
|
|
| 2701 |
|
|
reg [19:0] page[0:31];
|
| 2702 |
|
|
reg [19:0] frame[0:31];
|
| 2703 |
|
|
|
| 2704 |
|
|
wire [19:0] p00, p01, p02, p03;
|
| 2705 |
|
|
wire [19:0] p04, p05, p06, p07;
|
| 2706 |
|
|
wire [19:0] p08, p09, p10, p11;
|
| 2707 |
|
|
wire [19:0] p12, p13, p14, p15;
|
| 2708 |
|
|
wire [19:0] p16, p17, p18, p19;
|
| 2709 |
|
|
wire [19:0] p20, p21, p22, p23;
|
| 2710 |
|
|
wire [19:0] p24, p25, p26, p27;
|
| 2711 |
|
|
wire [19:0] p28, p29, p30, p31;
|
| 2712 |
|
|
wire [31:0] match;
|
| 2713 |
|
|
|
| 2714 |
|
|
assign p00 = page[ 0];
|
| 2715 |
|
|
assign p01 = page[ 1];
|
| 2716 |
|
|
assign p02 = page[ 2];
|
| 2717 |
|
|
assign p03 = page[ 3];
|
| 2718 |
|
|
assign p04 = page[ 4];
|
| 2719 |
|
|
assign p05 = page[ 5];
|
| 2720 |
|
|
assign p06 = page[ 6];
|
| 2721 |
|
|
assign p07 = page[ 7];
|
| 2722 |
|
|
assign p08 = page[ 8];
|
| 2723 |
|
|
assign p09 = page[ 9];
|
| 2724 |
|
|
assign p10 = page[10];
|
| 2725 |
|
|
assign p11 = page[11];
|
| 2726 |
|
|
assign p12 = page[12];
|
| 2727 |
|
|
assign p13 = page[13];
|
| 2728 |
|
|
assign p14 = page[14];
|
| 2729 |
|
|
assign p15 = page[15];
|
| 2730 |
|
|
assign p16 = page[16];
|
| 2731 |
|
|
assign p17 = page[17];
|
| 2732 |
|
|
assign p18 = page[18];
|
| 2733 |
|
|
assign p19 = page[19];
|
| 2734 |
|
|
assign p20 = page[20];
|
| 2735 |
|
|
assign p21 = page[21];
|
| 2736 |
|
|
assign p22 = page[22];
|
| 2737 |
|
|
assign p23 = page[23];
|
| 2738 |
|
|
assign p24 = page[24];
|
| 2739 |
|
|
assign p25 = page[25];
|
| 2740 |
|
|
assign p26 = page[26];
|
| 2741 |
|
|
assign p27 = page[27];
|
| 2742 |
|
|
assign p28 = page[28];
|
| 2743 |
|
|
assign p29 = page[29];
|
| 2744 |
|
|
assign p30 = page[30];
|
| 2745 |
|
|
assign p31 = page[31];
|
| 2746 |
|
|
|
| 2747 |
|
|
assign match[ 0] = (page_in == p00) ? 1 : 0;
|
| 2748 |
|
|
assign match[ 1] = (page_in == p01) ? 1 : 0;
|
| 2749 |
|
|
assign match[ 2] = (page_in == p02) ? 1 : 0;
|
| 2750 |
|
|
assign match[ 3] = (page_in == p03) ? 1 : 0;
|
| 2751 |
|
|
assign match[ 4] = (page_in == p04) ? 1 : 0;
|
| 2752 |
|
|
assign match[ 5] = (page_in == p05) ? 1 : 0;
|
| 2753 |
|
|
assign match[ 6] = (page_in == p06) ? 1 : 0;
|
| 2754 |
|
|
assign match[ 7] = (page_in == p07) ? 1 : 0;
|
| 2755 |
|
|
assign match[ 8] = (page_in == p08) ? 1 : 0;
|
| 2756 |
|
|
assign match[ 9] = (page_in == p09) ? 1 : 0;
|
| 2757 |
|
|
assign match[10] = (page_in == p10) ? 1 : 0;
|
| 2758 |
|
|
assign match[11] = (page_in == p11) ? 1 : 0;
|
| 2759 |
|
|
assign match[12] = (page_in == p12) ? 1 : 0;
|
| 2760 |
|
|
assign match[13] = (page_in == p13) ? 1 : 0;
|
| 2761 |
|
|
assign match[14] = (page_in == p14) ? 1 : 0;
|
| 2762 |
|
|
assign match[15] = (page_in == p15) ? 1 : 0;
|
| 2763 |
|
|
assign match[16] = (page_in == p16) ? 1 : 0;
|
| 2764 |
|
|
assign match[17] = (page_in == p17) ? 1 : 0;
|
| 2765 |
|
|
assign match[18] = (page_in == p18) ? 1 : 0;
|
| 2766 |
|
|
assign match[19] = (page_in == p19) ? 1 : 0;
|
| 2767 |
|
|
assign match[20] = (page_in == p20) ? 1 : 0;
|
| 2768 |
|
|
assign match[21] = (page_in == p21) ? 1 : 0;
|
| 2769 |
|
|
assign match[22] = (page_in == p22) ? 1 : 0;
|
| 2770 |
|
|
assign match[23] = (page_in == p23) ? 1 : 0;
|
| 2771 |
|
|
assign match[24] = (page_in == p24) ? 1 : 0;
|
| 2772 |
|
|
assign match[25] = (page_in == p25) ? 1 : 0;
|
| 2773 |
|
|
assign match[26] = (page_in == p26) ? 1 : 0;
|
| 2774 |
|
|
assign match[27] = (page_in == p27) ? 1 : 0;
|
| 2775 |
|
|
assign match[28] = (page_in == p28) ? 1 : 0;
|
| 2776 |
|
|
assign match[29] = (page_in == p29) ? 1 : 0;
|
| 2777 |
|
|
assign match[30] = (page_in == p30) ? 1 : 0;
|
| 2778 |
|
|
assign match[31] = (page_in == p31) ? 1 : 0;
|
| 2779 |
|
|
|
| 2780 |
|
|
assign miss = ~(| match[31:0]);
|
| 2781 |
|
|
|
| 2782 |
|
|
assign found[0] = match[ 1] | match[ 3] | match[ 5] | match[ 7] |
|
| 2783 |
|
|
match[ 9] | match[11] | match[13] | match[15] |
|
| 2784 |
|
|
match[17] | match[19] | match[21] | match[23] |
|
| 2785 |
|
|
match[25] | match[27] | match[29] | match[31];
|
| 2786 |
|
|
assign found[1] = match[ 2] | match[ 3] | match[ 6] | match[ 7] |
|
| 2787 |
|
|
match[10] | match[11] | match[14] | match[15] |
|
| 2788 |
|
|
match[18] | match[19] | match[22] | match[23] |
|
| 2789 |
|
|
match[26] | match[27] | match[30] | match[31];
|
| 2790 |
|
|
assign found[2] = match[ 4] | match[ 5] | match[ 6] | match[ 7] |
|
| 2791 |
|
|
match[12] | match[13] | match[14] | match[15] |
|
| 2792 |
|
|
match[20] | match[21] | match[22] | match[23] |
|
| 2793 |
|
|
match[28] | match[29] | match[30] | match[31];
|
| 2794 |
|
|
assign found[3] = match[ 8] | match[ 9] | match[10] | match[11] |
|
| 2795 |
|
|
match[12] | match[13] | match[14] | match[15] |
|
| 2796 |
|
|
match[24] | match[25] | match[26] | match[27] |
|
| 2797 |
|
|
match[28] | match[29] | match[30] | match[31];
|
| 2798 |
|
|
assign found[4] = match[16] | match[17] | match[18] | match[19] |
|
| 2799 |
|
|
match[20] | match[21] | match[22] | match[23] |
|
| 2800 |
|
|
match[24] | match[25] | match[26] | match[27] |
|
| 2801 |
|
|
match[28] | match[29] | match[30] | match[31];
|
| 2802 |
|
|
|
| 2803 |
|
|
always @(posedge clk) begin
|
| 2804 |
|
|
if (enable == 1) begin
|
| 2805 |
|
|
frame_out <= frame[found];
|
| 2806 |
|
|
end
|
| 2807 |
|
|
end
|
| 2808 |
|
|
|
| 2809 |
|
|
always @(posedge clk) begin
|
| 2810 |
|
|
if (w_enable == 1) begin
|
| 2811 |
|
|
page[rw_index] <= w_page;
|
| 2812 |
|
|
frame[rw_index] <= w_frame;
|
| 2813 |
|
|
end else begin
|
| 2814 |
|
|
r_page <= page[rw_index];
|
| 2815 |
|
|
r_frame <= frame[rw_index];
|
| 2816 |
|
|
end
|
| 2817 |
|
|
end
|
| 2818 |
|
|
|
| 2819 |
|
|
endmodule
|
