//////////////////////////////////////////////////////////////////////
|
//////////////////////////////////////////////////////////////////////
|
//// ////
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//// ////
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//// OR1200's Top level multiplier, divider and MAC ////
|
//// OR1200's Top level multiplier, divider and MAC ////
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//// ////
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//// ////
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//// This file is part of the OpenRISC 1200 project ////
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//// This file is part of the OpenRISC 1200 project ////
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//// http://opencores.org/project,or1k ////
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//// http://opencores.org/project,or1k ////
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//// ////
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//// ////
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//// Description ////
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//// Description ////
|
//// Multiplier is 32x32 however multiply instructions only ////
|
//// Multiplier is 32x32 however multiply instructions only ////
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//// use lower 32 bits of the result. MAC is 32x32=64+64. ////
|
//// use lower 32 bits of the result. MAC is 32x32=64+64. ////
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//// ////
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//// ////
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//// To Do: ////
|
//// To Do: ////
|
//// - make signed division better, w/o negating the operands ////
|
//// - make signed division better, w/o negating the operands ////
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//// - implement non-serial divider that is synthesizable ////
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//// - implement non-serial divider that is synthesizable ////
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//// ////
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//// ////
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//// Author(s): ////
|
//// Author(s): ////
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//// - Damjan Lampret, lampret@opencores.org ////
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//// - Damjan Lampret, lampret@opencores.org ////
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//// - Julius Baxter, julius@opencores.org ////
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//// - Julius Baxter, julius@opencores.org ////
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//// ////
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//// ////
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//////////////////////////////////////////////////////////////////////
|
//////////////////////////////////////////////////////////////////////
|
//// ////
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//// ////
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//// Copyright (C) 2000, 2010 Authors and OPENCORES.ORG ////
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//// Copyright (C) 2000, 2010 Authors and OPENCORES.ORG ////
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//// ////
|
//// ////
|
//// This source file may be used and distributed without ////
|
//// This source file may be used and distributed without ////
|
//// restriction provided that this copyright statement is not ////
|
//// restriction provided that this copyright statement is not ////
|
//// removed from the file and that any derivative work contains ////
|
//// removed from the file and that any derivative work contains ////
|
//// the original copyright notice and the associated disclaimer. ////
|
//// the original copyright notice and the associated disclaimer. ////
|
//// ////
|
//// ////
|
//// This source file is free software; you can redistribute it ////
|
//// This source file is free software; you can redistribute it ////
|
//// and/or modify it under the terms of the GNU Lesser General ////
|
//// and/or modify it under the terms of the GNU Lesser General ////
|
//// Public License as published by the Free Software Foundation; ////
|
//// Public License as published by the Free Software Foundation; ////
|
//// either version 2.1 of the License, or (at your option) any ////
|
//// either version 2.1 of the License, or (at your option) any ////
|
//// later version. ////
|
//// later version. ////
|
//// ////
|
//// ////
|
//// This source is distributed in the hope that it will be ////
|
//// This source is distributed in the hope that it will be ////
|
//// useful, but WITHOUT ANY WARRANTY; without even the implied ////
|
//// useful, but WITHOUT ANY WARRANTY; without even the implied ////
|
//// warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR ////
|
//// warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR ////
|
//// PURPOSE. See the GNU Lesser General Public License for more ////
|
//// PURPOSE. See the GNU Lesser General Public License for more ////
|
//// details. ////
|
//// details. ////
|
//// ////
|
//// ////
|
//// You should have received a copy of the GNU Lesser General ////
|
//// You should have received a copy of the GNU Lesser General ////
|
//// Public License along with this source; if not, download it ////
|
//// Public License along with this source; if not, download it ////
|
//// from http://www.opencores.org/lgpl.shtml ////
|
//// from http://www.opencores.org/lgpl.shtml ////
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//// ////
|
//// ////
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//////////////////////////////////////////////////////////////////////
|
//////////////////////////////////////////////////////////////////////
|
//
|
//
|
// CVS Revision History
|
// CVS Revision History
|
//
|
//
|
// $Log: or1200_mult_mac.v,v $
|
// $Log: or1200_mult_mac.v,v $
|
// Revision 2.0 2010/06/30 11:00:00 ORSoC
|
// Revision 2.0 2010/06/30 11:00:00 ORSoC
|
// Minor update:
|
// Minor update:
|
// Bugs fixed.
|
// Bugs fixed.
|
//
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//
|
|
|
// synopsys translate_off
|
// synopsys translate_off
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`include "timescale.v"
|
`include "timescale.v"
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// synopsys translate_on
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// synopsys translate_on
|
`include "or1200_defines.v"
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`include "or1200_defines.v"
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|
|
module or1200_mult_mac(
|
module or1200_mult_mac(
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// Clock and reset
|
// Clock and reset
|
clk, rst,
|
clk, rst,
|
|
|
// Multiplier/MAC interface
|
// Multiplier/MAC interface
|
ex_freeze, id_macrc_op, macrc_op, a, b, mac_op, alu_op,
|
ex_freeze, id_macrc_op, macrc_op, a, b, mac_op, alu_op,
|
result, mult_mac_stall,
|
result, mult_mac_stall,
|
|
|
// SPR interface
|
// SPR interface
|
spr_cs, spr_write, spr_addr, spr_dat_i, spr_dat_o
|
spr_cs, spr_write, spr_addr, spr_dat_i, spr_dat_o
|
);
|
);
|
|
|
parameter width = `OR1200_OPERAND_WIDTH;
|
parameter width = `OR1200_OPERAND_WIDTH;
|
|
|
//
|
//
|
// I/O
|
// I/O
|
//
|
//
|
|
|
//
|
//
|
// Clock and reset
|
// Clock and reset
|
//
|
//
|
input clk;
|
input clk;
|
input rst;
|
input rst;
|
|
|
//
|
//
|
// Multiplier/MAC interface
|
// Multiplier/MAC interface
|
//
|
//
|
input ex_freeze;
|
input ex_freeze;
|
input id_macrc_op;
|
input id_macrc_op;
|
input macrc_op;
|
input macrc_op;
|
input [width-1:0] a;
|
input [width-1:0] a;
|
input [width-1:0] b;
|
input [width-1:0] b;
|
input [`OR1200_MACOP_WIDTH-1:0] mac_op;
|
input [`OR1200_MACOP_WIDTH-1:0] mac_op;
|
input [`OR1200_ALUOP_WIDTH-1:0] alu_op;
|
input [`OR1200_ALUOP_WIDTH-1:0] alu_op;
|
output [width-1:0] result;
|
output [width-1:0] result;
|
output mult_mac_stall;
|
output mult_mac_stall;
|
|
|
//
|
//
|
// SPR interface
|
// SPR interface
|
//
|
//
|
input spr_cs;
|
input spr_cs;
|
input spr_write;
|
input spr_write;
|
input [31:0] spr_addr;
|
input [31:0] spr_addr;
|
input [31:0] spr_dat_i;
|
input [31:0] spr_dat_i;
|
output [31:0] spr_dat_o;
|
output [31:0] spr_dat_o;
|
|
|
//
|
//
|
// Internal wires and regs
|
// Internal wires and regs
|
//
|
//
|
reg [width-1:0] result;
|
reg [width-1:0] result;
|
|
reg ex_freeze_r;
|
`ifdef OR1200_MULT_IMPLEMENTED
|
`ifdef OR1200_MULT_IMPLEMENTED
|
reg [2*width-1:0] mul_prod_r;
|
reg [2*width-1:0] mul_prod_r;
|
wire alu_op_smul;
|
wire alu_op_smul;
|
wire alu_op_umul;
|
wire alu_op_umul;
|
wire alu_op_mul;
|
wire alu_op_mul;
|
`ifdef OR1200_MULT_SERIAL
|
`ifdef OR1200_MULT_SERIAL
|
reg [5:0] serial_mul_cnt;
|
reg [5:0] serial_mul_cnt;
|
reg mul_free;
|
reg mul_free;
|
`endif
|
`endif
|
`else
|
`else
|
wire [2*width-1:0] mul_prod_r;
|
wire [2*width-1:0] mul_prod_r;
|
`endif
|
`endif
|
wire [2*width-1:0] mul_prod;
|
wire [2*width-1:0] mul_prod;
|
wire mul_stall;
|
wire mul_stall;
|
|
reg [1:0] mul_stall_count;
|
wire [`OR1200_MACOP_WIDTH-1:0] mac_op;
|
wire [`OR1200_MACOP_WIDTH-1:0] mac_op;
|
`ifdef OR1200_MAC_IMPLEMENTED
|
`ifdef OR1200_MAC_IMPLEMENTED
|
reg [`OR1200_MACOP_WIDTH-1:0] mac_op_r1;
|
reg [`OR1200_MACOP_WIDTH-1:0] mac_op_r1;
|
reg [`OR1200_MACOP_WIDTH-1:0] mac_op_r2;
|
reg [`OR1200_MACOP_WIDTH-1:0] mac_op_r2;
|
reg [`OR1200_MACOP_WIDTH-1:0] mac_op_r3;
|
reg [`OR1200_MACOP_WIDTH-1:0] mac_op_r3;
|
reg mac_stall_r;
|
reg mac_stall_r;
|
reg [63:0] mac_r;
|
reg [63:0] mac_r;
|
`else
|
`else
|
wire [`OR1200_MACOP_WIDTH-1:0] mac_op_r1;
|
wire [`OR1200_MACOP_WIDTH-1:0] mac_op_r1;
|
wire [`OR1200_MACOP_WIDTH-1:0] mac_op_r2;
|
wire [`OR1200_MACOP_WIDTH-1:0] mac_op_r2;
|
wire [`OR1200_MACOP_WIDTH-1:0] mac_op_r3;
|
wire [`OR1200_MACOP_WIDTH-1:0] mac_op_r3;
|
wire mac_stall_r;
|
wire mac_stall_r;
|
wire [63:0] mac_r;
|
wire [63:0] mac_r;
|
`endif
|
`endif
|
wire [width-1:0] x;
|
wire [width-1:0] x;
|
wire [width-1:0] y;
|
wire [width-1:0] y;
|
wire spr_maclo_we;
|
wire spr_maclo_we;
|
wire spr_machi_we;
|
wire spr_machi_we;
|
wire alu_op_div;
|
wire alu_op_div;
|
wire alu_op_udiv;
|
wire alu_op_udiv;
|
wire alu_op_sdiv;
|
wire alu_op_sdiv;
|
reg div_free;
|
reg div_free;
|
wire div_stall;
|
wire div_stall;
|
`ifdef OR1200_DIV_IMPLEMENTED
|
`ifdef OR1200_DIV_IMPLEMENTED
|
`ifdef OR1200_DIV_SERIAL
|
`ifdef OR1200_DIV_SERIAL
|
reg [2*width-1:0] div_quot_r;
|
reg [2*width-1:0] div_quot_r;
|
wire [width-1:0] div_tmp;
|
wire [width-1:0] div_tmp;
|
reg [5:0] div_cntr;
|
reg [5:0] div_cntr;
|
`else
|
`else
|
reg [width-1:0] div_quot_r;
|
reg [width-1:0] div_quot_r;
|
reg [width-1:0] div_quot_generic;
|
reg [width-1:0] div_quot_generic;
|
`endif
|
`endif
|
`endif
|
`endif
|
|
|
//
|
//
|
// Combinatorial logic
|
// Combinatorial logic
|
//
|
//
|
`ifdef OR1200_MULT_IMPLEMENTED
|
`ifdef OR1200_MULT_IMPLEMENTED
|
assign alu_op_smul = (alu_op == `OR1200_ALUOP_MUL);
|
assign alu_op_smul = (alu_op == `OR1200_ALUOP_MUL);
|
assign alu_op_umul = (alu_op == `OR1200_ALUOP_MULU);
|
assign alu_op_umul = (alu_op == `OR1200_ALUOP_MULU);
|
assign alu_op_mul = alu_op_smul | alu_op_umul;
|
assign alu_op_mul = alu_op_smul | alu_op_umul;
|
`endif
|
`endif
|
`ifdef OR1200_MAC_IMPLEMENTED
|
`ifdef OR1200_MAC_IMPLEMENTED
|
assign spr_maclo_we = spr_cs & spr_write & spr_addr[`OR1200_MAC_ADDR];
|
assign spr_maclo_we = spr_cs & spr_write & spr_addr[`OR1200_MAC_ADDR];
|
assign spr_machi_we = spr_cs & spr_write & !spr_addr[`OR1200_MAC_ADDR];
|
assign spr_machi_we = spr_cs & spr_write & !spr_addr[`OR1200_MAC_ADDR];
|
assign spr_dat_o = spr_addr[`OR1200_MAC_ADDR] ? mac_r[31:0] : mac_r[63:32];
|
assign spr_dat_o = spr_addr[`OR1200_MAC_ADDR] ? mac_r[31:0] : mac_r[63:32];
|
`else
|
`else
|
assign spr_maclo_we = 1'b0;
|
assign spr_maclo_we = 1'b0;
|
assign spr_machi_we = 1'b0;
|
assign spr_machi_we = 1'b0;
|
assign spr_dat_o = 32'h0000_0000;
|
assign spr_dat_o = 32'h0000_0000;
|
`endif
|
`endif
|
`ifdef OR1200_DIV_IMPLEMENTED
|
`ifdef OR1200_DIV_IMPLEMENTED
|
assign alu_op_sdiv = (alu_op == `OR1200_ALUOP_DIV);
|
assign alu_op_sdiv = (alu_op == `OR1200_ALUOP_DIV);
|
assign alu_op_udiv = (alu_op == `OR1200_ALUOP_DIVU);
|
assign alu_op_udiv = (alu_op == `OR1200_ALUOP_DIVU);
|
assign alu_op_div = alu_op_sdiv | alu_op_udiv;
|
assign alu_op_div = alu_op_sdiv | alu_op_udiv;
|
`else
|
`else
|
assign alu_op_udiv = 1'b0;
|
assign alu_op_udiv = 1'b0;
|
assign alu_op_sdiv = 1'b0;
|
assign alu_op_sdiv = 1'b0;
|
assign alu_op_div = 1'b0;
|
assign alu_op_div = 1'b0;
|
`endif
|
`endif
|
|
|
assign x = (alu_op_sdiv | alu_op_smul) & a[31] ? ~a + 32'b1 :
|
assign x = (alu_op_sdiv | alu_op_smul) & a[31] ? ~a + 32'b1 :
|
alu_op_div | alu_op_mul | (|mac_op) ? a : 32'd0;
|
alu_op_div | alu_op_mul | (|mac_op) ? a : 32'd0;
|
assign y = (alu_op_sdiv | alu_op_smul) & b[31] ? ~b + 32'b1 :
|
assign y = (alu_op_sdiv | alu_op_smul) & b[31] ? ~b + 32'b1 :
|
alu_op_div | alu_op_mul | (|mac_op) ? b : 32'd0;
|
alu_op_div | alu_op_mul | (|mac_op) ? b : 32'd0;
|
|
|
|
// Used to indicate when we should check for new multiply or MAC ops
|
|
always @(posedge clk or `OR1200_RST_EVENT rst)
|
|
if (rst == `OR1200_RST_VALUE)
|
|
ex_freeze_r <= 1'b1;
|
|
else
|
|
ex_freeze_r <= ex_freeze;
|
|
|
//
|
//
|
// Select result of current ALU operation to be forwarded
|
// Select result of current ALU operation to be forwarded
|
// to next instruction and to WB stage
|
// to next instruction and to WB stage
|
//
|
//
|
always @*
|
always @*
|
casez(alu_op) // synopsys parallel_case
|
casez(alu_op) // synopsys parallel_case
|
`ifdef OR1200_DIV_IMPLEMENTED
|
`ifdef OR1200_DIV_IMPLEMENTED
|
`OR1200_ALUOP_DIV: begin
|
`OR1200_ALUOP_DIV: begin
|
result = a[31] ^ b[31] ? ~div_quot_r[31:0] + 32'd1 : div_quot_r[31:0];
|
result = a[31] ^ b[31] ? ~div_quot_r[31:0] + 32'd1 : div_quot_r[31:0];
|
end
|
end
|
`OR1200_ALUOP_DIVU: begin
|
`OR1200_ALUOP_DIVU: begin
|
result = div_quot_r[31:0];
|
result = div_quot_r[31:0];
|
end
|
end
|
`endif
|
`endif
|
`ifdef OR1200_MULT_IMPLEMENTED
|
`ifdef OR1200_MULT_IMPLEMENTED
|
`OR1200_ALUOP_MUL: begin
|
`OR1200_ALUOP_MUL: begin
|
result = a[31] ^ b[31] ? ~mul_prod_r[31:0] + 32'd1 : mul_prod_r[31:0];
|
result = a[31] ^ b[31] ? ~mul_prod_r[31:0] + 32'd1 : mul_prod_r[31:0];
|
end
|
end
|
`OR1200_ALUOP_MULU: begin
|
`OR1200_ALUOP_MULU: begin
|
result = mul_prod_r[31:0];
|
result = mul_prod_r[31:0];
|
end
|
end
|
`endif
|
`endif
|
default:
|
default:
|
`ifdef OR1200_MAC_IMPLEMENTED
|
`ifdef OR1200_MAC_IMPLEMENTED
|
`ifdef OR1200_MAC_SHIFTBY
|
`ifdef OR1200_MAC_SHIFTBY
|
result = mac_r[`OR1200_MAC_SHIFTBY+31:`OR1200_MAC_SHIFTBY];
|
result = mac_r[`OR1200_MAC_SHIFTBY+31:`OR1200_MAC_SHIFTBY];
|
`else
|
`else
|
result = mac_r[31:0];
|
result = mac_r[31:0];
|
`endif
|
`endif
|
`else
|
`else
|
result = {width{1'b0}};
|
result = {width{1'b0}};
|
`endif
|
`endif
|
endcase
|
endcase
|
|
|
`ifdef OR1200_MULT_IMPLEMENTED
|
`ifdef OR1200_MULT_IMPLEMENTED
|
`ifdef OR1200_MULT_SERIAL
|
`ifdef OR1200_MULT_SERIAL
|
|
|
always @(`OR1200_RST_EVENT rst or posedge clk)
|
always @(`OR1200_RST_EVENT rst or posedge clk)
|
if (rst == `OR1200_RST_VALUE) begin
|
if (rst == `OR1200_RST_VALUE) begin
|
mul_prod_r <= 64'h0000_0000_0000_0000;
|
mul_prod_r <= 64'h0000_0000_0000_0000;
|
serial_mul_cnt <= 6'd0;
|
serial_mul_cnt <= 6'd0;
|
mul_free <= 1'b1;
|
mul_free <= 1'b1;
|
|
|
end
|
end
|
else if (|serial_mul_cnt) begin
|
else if (|serial_mul_cnt) begin
|
serial_mul_cnt <= serial_mul_cnt - 6'd1;
|
serial_mul_cnt <= serial_mul_cnt - 6'd1;
|
if (mul_prod_r[0])
|
if (mul_prod_r[0])
|
mul_prod_r[(width*2)-1:width-1] <= mul_prod_r[(width*2)-1:width] + x;
|
mul_prod_r[(width*2)-1:width-1] <= mul_prod_r[(width*2)-1:width] + x;
|
else
|
else
|
mul_prod_r[(width*2)-1:width-1] <= {1'b0,mul_prod_r[(width*2)-1:
|
mul_prod_r[(width*2)-1:width-1] <= {1'b0,mul_prod_r[(width*2)-1:
|
width]};
|
width]};
|
mul_prod_r[width-2:0] <= mul_prod_r[width-1:1];
|
mul_prod_r[width-2:0] <= mul_prod_r[width-1:1];
|
|
|
end
|
end
|
else if (alu_op_mul && mul_free) begin
|
else if (alu_op_mul && mul_free) begin
|
mul_prod_r <= {32'd0, y};
|
mul_prod_r <= {32'd0, y};
|
mul_free <= 0;
|
mul_free <= 0;
|
serial_mul_cnt <= 6'b10_0000;
|
serial_mul_cnt <= 6'b10_0000;
|
end
|
end
|
else if (!ex_freeze | mul_free) begin
|
else if (!ex_freeze | mul_free) begin
|
mul_free <= 1'b1;
|
mul_free <= 1'b1;
|
end
|
end
|
|
|
assign mul_stall = (|serial_mul_cnt);
|
assign mul_stall = (|serial_mul_cnt);
|
|
|
`else
|
`else
|
|
|
//
|
//
|
// Instantiation of the multiplier
|
// Instantiation of the multiplier
|
//
|
//
|
`ifdef OR1200_ASIC_MULTP2_32X32
|
`ifdef OR1200_ASIC_MULTP2_32X32
|
or1200_amultp2_32x32 or1200_amultp2_32x32(
|
or1200_amultp2_32x32 or1200_amultp2_32x32(
|
.X(x),
|
.X(x),
|
.Y(y),
|
.Y(y),
|
.RST(rst),
|
.RST(rst),
|
.CLK(clk),
|
.CLK(clk),
|
.P(mul_prod)
|
.P(mul_prod)
|
);
|
);
|
`else // OR1200_ASIC_MULTP2_32X32
|
`else // OR1200_ASIC_MULTP2_32X32
|
or1200_gmultp2_32x32 or1200_gmultp2_32x32(
|
or1200_gmultp2_32x32 or1200_gmultp2_32x32(
|
.X(x),
|
.X(x),
|
.Y(y),
|
.Y(y),
|
.RST(rst),
|
.RST(rst),
|
.CLK(clk),
|
.CLK(clk),
|
.P(mul_prod)
|
.P(mul_prod)
|
);
|
);
|
`endif // OR1200_ASIC_MULTP2_32X32
|
`endif // OR1200_ASIC_MULTP2_32X32
|
|
|
//
|
//
|
// Registered output from the multiplier
|
// Registered output from the multiplier
|
//
|
//
|
always @(`OR1200_RST_EVENT rst or posedge clk)
|
always @(`OR1200_RST_EVENT rst or posedge clk)
|
if (rst == `OR1200_RST_VALUE) begin
|
if (rst == `OR1200_RST_VALUE) begin
|
mul_prod_r <= 64'h0000_0000_0000_0000;
|
mul_prod_r <= 64'h0000_0000_0000_0000;
|
end
|
end
|
else begin
|
else begin
|
mul_prod_r <= mul_prod[63:0];
|
mul_prod_r <= mul_prod[63:0];
|
end
|
end
|
|
|
assign mul_stall = 0;
|
//
|
|
// Generate stall signal during multiplication
|
|
//
|
|
always @(`OR1200_RST_EVENT rst or posedge clk)
|
|
if (rst == `OR1200_RST_VALUE)
|
|
mul_stall_count <= 0;
|
|
else if (!(|mul_stall_count))
|
|
mul_stall_count <= {mul_stall_count[0], alu_op_mul & !ex_freeze_r};
|
|
else
|
|
mul_stall_count <= {mul_stall_count[0],1'b0};
|
|
|
|
assign mul_stall = (|mul_stall_count) |
|
|
(!(|mul_stall_count) & alu_op_mul & !ex_freeze_r);
|
|
|
`endif // !`ifdef OR1200_MULT_SERIAL
|
`endif // !`ifdef OR1200_MULT_SERIAL
|
|
|
`else // OR1200_MULT_IMPLEMENTED
|
`else // OR1200_MULT_IMPLEMENTED
|
assign mul_prod = {2*width{1'b0}};
|
assign mul_prod = {2*width{1'b0}};
|
assign mul_prod_r = {2*width{1'b0}};
|
assign mul_prod_r = {2*width{1'b0}};
|
assign mul_stall = 0;
|
assign mul_stall = 0;
|
`endif // OR1200_MULT_IMPLEMENTED
|
`endif // OR1200_MULT_IMPLEMENTED
|
|
|
`ifdef OR1200_MAC_IMPLEMENTED
|
`ifdef OR1200_MAC_IMPLEMENTED
|
// Signal to indicate when we should check for new MAC op
|
|
reg ex_freeze_r;
|
|
|
|
always @(posedge clk or `OR1200_RST_EVENT rst)
|
|
if (rst == `OR1200_RST_VALUE)
|
|
ex_freeze_r <= 1'b1;
|
|
else
|
|
ex_freeze_r <= ex_freeze;
|
|
|
|
//
|
//
|
// Propagation of l.mac opcode, only register it for one cycle
|
// Propagation of l.mac opcode, only register it for one cycle
|
//
|
//
|
always @(posedge clk or `OR1200_RST_EVENT rst)
|
always @(posedge clk or `OR1200_RST_EVENT rst)
|
if (rst == `OR1200_RST_VALUE)
|
if (rst == `OR1200_RST_VALUE)
|
mac_op_r1 <= `OR1200_MACOP_WIDTH'b0;
|
mac_op_r1 <= `OR1200_MACOP_WIDTH'b0;
|
else
|
else
|
mac_op_r1 <= !ex_freeze_r ? mac_op : `OR1200_MACOP_WIDTH'b0;
|
mac_op_r1 <= !ex_freeze_r ? mac_op : `OR1200_MACOP_WIDTH'b0;
|
|
|
//
|
//
|
// Propagation of l.mac opcode
|
// Propagation of l.mac opcode
|
//
|
//
|
always @(posedge clk or `OR1200_RST_EVENT rst)
|
always @(posedge clk or `OR1200_RST_EVENT rst)
|
if (rst == `OR1200_RST_VALUE)
|
if (rst == `OR1200_RST_VALUE)
|
mac_op_r2 <= `OR1200_MACOP_WIDTH'b0;
|
mac_op_r2 <= `OR1200_MACOP_WIDTH'b0;
|
else
|
else
|
mac_op_r2 <= mac_op_r1;
|
mac_op_r2 <= mac_op_r1;
|
|
|
//
|
//
|
// Propagation of l.mac opcode
|
// Propagation of l.mac opcode
|
//
|
//
|
always @(posedge clk or `OR1200_RST_EVENT rst)
|
always @(posedge clk or `OR1200_RST_EVENT rst)
|
if (rst == `OR1200_RST_VALUE)
|
if (rst == `OR1200_RST_VALUE)
|
mac_op_r3 <= `OR1200_MACOP_WIDTH'b0;
|
mac_op_r3 <= `OR1200_MACOP_WIDTH'b0;
|
else
|
else
|
mac_op_r3 <= mac_op_r2;
|
mac_op_r3 <= mac_op_r2;
|
|
|
//
|
//
|
// Implementation of MAC
|
// Implementation of MAC
|
//
|
//
|
always @(`OR1200_RST_EVENT rst or posedge clk)
|
always @(`OR1200_RST_EVENT rst or posedge clk)
|
if (rst == `OR1200_RST_VALUE)
|
if (rst == `OR1200_RST_VALUE)
|
mac_r <= 64'h0000_0000_0000_0000;
|
mac_r <= 64'h0000_0000_0000_0000;
|
`ifdef OR1200_MAC_SPR_WE
|
`ifdef OR1200_MAC_SPR_WE
|
else if (spr_maclo_we)
|
else if (spr_maclo_we)
|
mac_r[31:0] <= spr_dat_i;
|
mac_r[31:0] <= spr_dat_i;
|
else if (spr_machi_we)
|
else if (spr_machi_we)
|
mac_r[63:32] <= spr_dat_i;
|
mac_r[63:32] <= spr_dat_i;
|
`endif
|
`endif
|
else if (mac_op_r3 == `OR1200_MACOP_MAC)
|
else if (mac_op_r3 == `OR1200_MACOP_MAC)
|
mac_r <= mac_r + mul_prod_r;
|
mac_r <= mac_r + mul_prod_r;
|
else if (mac_op_r3 == `OR1200_MACOP_MSB)
|
else if (mac_op_r3 == `OR1200_MACOP_MSB)
|
mac_r <= mac_r - mul_prod_r;
|
mac_r <= mac_r - mul_prod_r;
|
else if (macrc_op && !ex_freeze)
|
else if (macrc_op && !ex_freeze)
|
mac_r <= 64'h0000_0000_0000_0000;
|
mac_r <= 64'h0000_0000_0000_0000;
|
|
|
//
|
//
|
// Stall CPU if l.macrc is in ID and MAC still has to process l.mac
|
// Stall CPU if l.macrc is in ID and MAC still has to process l.mac
|
// instructions in EX stage (e.g. inside multiplier)
|
// instructions in EX stage (e.g. inside multiplier)
|
// This stall signal is also used by the divider.
|
// This stall signal is also used by the divider.
|
//
|
//
|
always @(`OR1200_RST_EVENT rst or posedge clk)
|
always @(`OR1200_RST_EVENT rst or posedge clk)
|
if (rst == `OR1200_RST_VALUE)
|
if (rst == `OR1200_RST_VALUE)
|
mac_stall_r <= 1'b0;
|
mac_stall_r <= 1'b0;
|
else
|
else
|
mac_stall_r <= (|mac_op | (|mac_op_r1) | (|mac_op_r2)) &
|
mac_stall_r <= (|mac_op | (|mac_op_r1) | (|mac_op_r2)) &
|
(id_macrc_op | mac_stall_r);
|
(id_macrc_op | mac_stall_r);
|
|
|
`else // OR1200_MAC_IMPLEMENTED
|
`else // OR1200_MAC_IMPLEMENTED
|
assign mac_stall_r = 1'b0;
|
assign mac_stall_r = 1'b0;
|
assign mac_r = {2*width{1'b0}};
|
assign mac_r = {2*width{1'b0}};
|
assign mac_op_r1 = `OR1200_MACOP_WIDTH'b0;
|
assign mac_op_r1 = `OR1200_MACOP_WIDTH'b0;
|
assign mac_op_r2 = `OR1200_MACOP_WIDTH'b0;
|
assign mac_op_r2 = `OR1200_MACOP_WIDTH'b0;
|
assign mac_op_r3 = `OR1200_MACOP_WIDTH'b0;
|
assign mac_op_r3 = `OR1200_MACOP_WIDTH'b0;
|
`endif // OR1200_MAC_IMPLEMENTED
|
`endif // OR1200_MAC_IMPLEMENTED
|
|
|
`ifdef OR1200_DIV_IMPLEMENTED
|
`ifdef OR1200_DIV_IMPLEMENTED
|
|
|
//
|
//
|
// Serial division
|
// Serial division
|
//
|
//
|
`ifdef OR1200_DIV_SERIAL
|
`ifdef OR1200_DIV_SERIAL
|
assign div_tmp = div_quot_r[63:32] - y;
|
assign div_tmp = div_quot_r[63:32] - y;
|
always @(`OR1200_RST_EVENT rst or posedge clk)
|
always @(`OR1200_RST_EVENT rst or posedge clk)
|
if (rst == `OR1200_RST_VALUE) begin
|
if (rst == `OR1200_RST_VALUE) begin
|
div_quot_r <= 64'h0000_0000_0000_0000;
|
div_quot_r <= 64'h0000_0000_0000_0000;
|
div_free <= 1'b1;
|
div_free <= 1'b1;
|
div_cntr <= 6'b00_0000;
|
div_cntr <= 6'b00_0000;
|
end
|
end
|
else if (|div_cntr) begin
|
else if (|div_cntr) begin
|
if (div_tmp[31])
|
if (div_tmp[31])
|
div_quot_r <= {div_quot_r[62:0], 1'b0};
|
div_quot_r <= {div_quot_r[62:0], 1'b0};
|
else
|
else
|
div_quot_r <= {div_tmp[30:0], div_quot_r[31:0], 1'b1};
|
div_quot_r <= {div_tmp[30:0], div_quot_r[31:0], 1'b1};
|
div_cntr <= div_cntr - 6'd1;
|
div_cntr <= div_cntr - 6'd1;
|
end
|
end
|
else if (alu_op_div && div_free) begin
|
else if (alu_op_div && div_free) begin
|
div_quot_r <= {31'b0, x[31:0], 1'b0};
|
div_quot_r <= {31'b0, x[31:0], 1'b0};
|
div_cntr <= 6'b10_0000;
|
div_cntr <= 6'b10_0000;
|
div_free <= 1'b0;
|
div_free <= 1'b0;
|
end
|
end
|
else if (div_free | !ex_freeze) begin
|
else if (div_free | !ex_freeze) begin
|
//div_quot_r <= div_quot[63:0];
|
//div_quot_r <= div_quot[63:0];
|
div_free <= 1'b1;
|
div_free <= 1'b1;
|
end
|
end
|
|
|
assign div_stall = (|div_cntr);
|
assign div_stall = (|div_cntr);
|
|
|
|
|
`else // !`ifdef OR1200_DIV_SERIAL
|
`else // !`ifdef OR1200_DIV_SERIAL
|
|
|
// Full divider
|
// Full divider
|
// TODO: Perhaps provide module that can be technology dependent.
|
// TODO: Perhaps provide module that can be technology dependent.
|
always @(`OR1200_RST_EVENT rst or posedge clk) begin
|
always @(`OR1200_RST_EVENT rst or posedge clk) begin
|
if (rst == `OR1200_RST_VALUE) begin
|
if (rst == `OR1200_RST_VALUE) begin
|
div_quot_r <= 32'd0;
|
div_quot_r <= 32'd0;
|
div_quot_generic <= 32'd0;
|
div_quot_generic <= 32'd0;
|
end
|
end
|
else begin
|
else begin
|
if (alu_op_udiv & !(|y)) // unsigned divide by 0 - force to MAX
|
if (alu_op_udiv & !(|y)) // unsigned divide by 0 - force to MAX
|
div_quot_generic[31:0] <= 32'hffff_ffff;
|
div_quot_generic[31:0] <= 32'hffff_ffff;
|
else if (alu_op_div)
|
else if (alu_op_div)
|
div_quot_generic[31:0] <= x / y;
|
div_quot_generic[31:0] <= x / y;
|
end
|
end
|
|
|
// Add any additional statges of pipelining as required here. Ensure
|
// Add any additional statges of pipelining as required here. Ensure
|
// ends with div_quot_r.
|
// ends with div_quot_r.
|
// Then add logic to ensure div_stall stays high for as long as the
|
// Then add logic to ensure div_stall stays high for as long as the
|
// division should take.
|
// division should take.
|
|
|
div_quot_r[31:0] <= div_quot_generic;
|
div_quot_r[31:0] <= div_quot_generic;
|
|
|
end
|
end
|
|
|
assign div_stall = 0;
|
assign div_stall = 0;
|
|
|
`endif
|
`endif
|
|
|
`else // !`ifdef OR1200_DIV_IMPLEMENTED
|
`else // !`ifdef OR1200_DIV_IMPLEMENTED
|
|
|
assign div_stall = 0;
|
assign div_stall = 0;
|
|
|
`endif // !`ifdef OR1200_DIV_IMPLEMENTED
|
`endif // !`ifdef OR1200_DIV_IMPLEMENTED
|
|
|
|
|
//
|
//
|
// Stall output
|
// Stall output
|
//
|
//
|
assign mult_mac_stall = mac_stall_r | div_stall | mul_stall;
|
assign mult_mac_stall = mac_stall_r | div_stall | mul_stall;
|
|
|
endmodule
|
endmodule
|
|
|
