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//////////////////////////////////////////////////////////////////////

////                                                              ////

////  OR1200's Data Cache top level                               ////

////                                                              ////

////  This file is part of the OpenRISC 1200 project              ////

////  http://opencores.org/project,or1k                           ////

////                                                              ////

////  Description                                                 ////

////  Instantiation of all DC blocks.                             ////

////                                                              ////

////  To Do:                                                      ////

////   - Test error during line read or write                     ////

////                                                              ////

////  Author(s):                                                  ////

////      - Damjan Lampret, lampret@opencores.org                 ////

////      - Julius Baxter, julius@opencores.org                   ////

////                                                              ////

//////////////////////////////////////////////////////////////////////

////                                                              ////

//// Copyright (C) 2000, 2010 Authors and OPENCORES.ORG           ////

////                                                              ////

//// This source file may be used and distributed without         ////

//// restriction provided that this copyright statement is not    ////

//// removed from the file and that any derivative work contains  ////

//// the original copyright notice and the associated disclaimer. ////

////                                                              ////

//// This source file is free software; you can redistribute it   ////

//// and/or modify it under the terms of the GNU Lesser General   ////

//// Public License as published by the Free Software Foundation; ////

//// either version 2.1 of the License, or (at your option) any   ////

//// later version.                                               ////

////                                                              ////

//// This source is distributed in the hope that it will be       ////

//// useful, but WITHOUT ANY WARRANTY; without even the implied   ////

//// warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR      ////

//// PURPOSE.  See the GNU Lesser General Public License for more ////

//// details.                                                     ////

////                                                              ////

//// You should have received a copy of the GNU Lesser General    ////

//// Public License along with this source; if not, download it   ////

//// from http://www.opencores.org/lgpl.shtml                     ////

////                                                              ////

//////////////////////////////////////////////////////////////////////

//

//

// $Log: or1200_dc_top.v,v $

// Revision 2.0  2010/06/30 11:00:00  ORSoC

// Minor update: 

// Bugs fixed. 

//

// synopsys translate_off

`include "timescale.v"

// synopsys translate_on

`include "or1200_defines.v"

//

// Data cache

//

module or1200_dc_top(

        // Rst, clk and clock control

        clk, rst,

        // External i/f

        dcsb_dat_o, dcsb_adr_o, dcsb_cyc_o, dcsb_stb_o, dcsb_we_o, dcsb_sel_o,

        dcsb_cab_o, dcsb_dat_i, dcsb_ack_i, dcsb_err_i,

        // Internal i/f

        dc_en,

        dcqmem_adr_i, dcqmem_cycstb_i, dcqmem_ci_i,

        dcqmem_we_i, dcqmem_sel_i, dcqmem_tag_i, dcqmem_dat_i,

        dcqmem_dat_o, dcqmem_ack_o, dcqmem_rty_o, dcqmem_err_o, dcqmem_tag_o,

        dc_no_writethrough,

`ifdef OR1200_BIST

        // RAM BIST

        mbist_si_i, mbist_so_o, mbist_ctrl_i,

`endif

`ifdef OR1200_RAM_PARITY

        // Parity error indicator

        p_err,

`endif

        // SPRs

        spr_cs, spr_write, spr_dat_i, spr_addr, mtspr_dc_done

);

parameter dw = `OR1200_OPERAND_WIDTH;

parameter aw = `OR1200_OPERAND_WIDTH;

//

// I/O

//

//

// Clock and reset

//

input                           clk;

input                           rst;

//

// External I/F

//

output  [dw-1:0]         dcsb_dat_o;

output  [31:0]                   dcsb_adr_o;

output                          dcsb_cyc_o;

output                          dcsb_stb_o;

output                          dcsb_we_o;

output  [3:0]                    dcsb_sel_o;

output                          dcsb_cab_o;

input   [dw-1:0]         dcsb_dat_i;

input                           dcsb_ack_i;

input                           dcsb_err_i;

//

// Internal I/F

//

input                           dc_en;

input   [31:0]                   dcqmem_adr_i;

input                           dcqmem_cycstb_i;

input                           dcqmem_ci_i;

input                           dcqmem_we_i;

input   [3:0]                    dcqmem_sel_i;

input   [3:0]                    dcqmem_tag_i;

input   [dw-1:0]         dcqmem_dat_i;

output  [dw-1:0]         dcqmem_dat_o;

output                          dcqmem_ack_o;

output                          dcqmem_rty_o;

output                          dcqmem_err_o;

output  [3:0]                    dcqmem_tag_o;

input                           dc_no_writethrough;

`ifdef OR1200_BIST

//

// RAM BIST

//

input mbist_si_i;

input [`OR1200_MBIST_CTRL_WIDTH - 1:0] mbist_ctrl_i;

output mbist_so_o;

`endif

`ifdef OR1200_RAM_PARITY

output [1:0]                     p_err;

`endif

//

// SPR access

//

input                           spr_cs;

input                           spr_write;

input   [31:0]                   spr_dat_i;

input   [aw-1:0]         spr_addr;

output                          mtspr_dc_done;

`ifdef OR1200_NO_DC

// Bypass cache

// IF to external memory

assign dcsb_dat_o = dcqmem_dat_i;

assign dcsb_adr_o = dcqmem_adr_i;

assign dcsb_cyc_o = dcqmem_cycstb_i;

assign dcsb_stb_o = dcqmem_cycstb_i;

assign dcsb_we_o = dcqmem_we_i;

assign dcsb_sel_o = dcqmem_sel_i;

assign dcsb_cab_o = 1'b0;

// IF to internal memory

assign dcqmem_dat_o = dcsb_dat_i;

assign dcqmem_ack_o = dcsb_ack_i;

assign dcqmem_err_o = dcsb_err_i;

assign dcqmem_rty_o = ~dcqmem_ack_o;

assign dcqmem_tag_o = dcqmem_err_o ? `OR1200_DTAG_BE : dcqmem_tag_i;

assign mtspr_dc_done = 1'b1;

`ifdef OR1200_RAM_PARITY

assign p_err = 0;

`endif

`else

//

// Internal wires and regs

//

wire                            tag_v;

wire    [`OR1200_DCTAG_W-2:0]    tag;

wire                            dirty;

wire    [dw-1:0]         to_dcram;

wire    [dw-1:0]         from_dcram;

wire    [3:0]                    dcram_we;

wire                            dctag_we;

wire    [31:0]                   dc_addr;

wire                            dcfsm_biu_read;

wire                            dcfsm_biu_write;

wire                            dcfsm_dcram_di_sel;

wire                            dcfsm_biu_do_sel;

wire                            tagcomp_miss;

wire    [`OR1200_DCINDXH:`OR1200_DCLS]  dctag_addr;

wire                            dctag_en;

wire                            dctag_v;

wire                            dctag_dirty;

wire                            dc_block_invalidate;

wire                            dc_block_flush;

wire                            dc_block_writeback;

wire                            dcfsm_first_hit_ack;

wire                            dcfsm_first_miss_ack;

wire                            dcfsm_first_miss_err;

wire                            dcfsm_burst;

wire                            dcfsm_tag_we;

wire                            dcfsm_tag_valid;

wire                            dcfsm_tag_dirty;

`ifdef OR1200_BIST

//

// RAM BIST

//

wire                            mbist_ram_so;

wire                            mbist_tag_so;

wire                            mbist_ram_si = mbist_si_i;

wire                            mbist_tag_si = mbist_ram_so;

assign                          mbist_so_o = mbist_tag_so;

`endif

`ifdef OR1200_RAM_PARITY

wire [1:0]                       p_err_wire;

// Indicate an error if we're reading from the RAM (hit)

// Additionally, mask with tag_v as tag ram is properly cleared during

// init, whereas the data RAM is not.

assign p_err[0] = (dcqmem_ack_o & (!dcfsm_first_miss_ack | dc_en) &

                   !dcqmem_we_i) &

                  (tag_v & !p_err[1]) ? p_err_wire[0] : 0;

// Whenever there's a tag parity error and we have an instruction fetch

assign p_err[1] = (dctag_en & !dctag_we) ? p_err_wire[1] : 0;

`endif

// Address out to external bus - always from FSM   

assign dcsb_adr_o = dc_addr;

//

// SPR register decodes

//

`ifdef OR1200_DC_WRITETHROUGH

assign dc_block_invalidate = spr_cs & spr_write &

       ((spr_addr[`OR1200_SPRGRP_DC_ADR_WIDTH-1:0]==`OR1200_SPRGRP_DC_DCBIR) |

        (spr_addr[`OR1200_SPRGRP_DC_ADR_WIDTH-1:0]==`OR1200_SPRGRP_DC_DCBFR));

assign dc_block_flush = 0;

assign dc_block_writeback = 0;

`else

assign dc_block_invalidate = spr_cs & spr_write &

          (spr_addr[`OR1200_SPRGRP_DC_ADR_WIDTH-1:0]==`OR1200_SPRGRP_DC_DCBIR);

assign dc_block_flush =    spr_cs & spr_write &

           (spr_addr[`OR1200_SPRGRP_DC_ADR_WIDTH-1:0]==`OR1200_SPRGRP_DC_DCBFR);

assign dc_block_writeback =    spr_cs & spr_write &

           (spr_addr[`OR1200_SPRGRP_DC_ADR_WIDTH-1:0]==`OR1200_SPRGRP_DC_DCBWR);

`endif // !`ifdef OR1200_DC_WRITETHROUGH

assign dctag_we = dcfsm_tag_we | dc_block_invalidate;

assign dctag_addr = dc_block_invalidate ?

                    spr_dat_i[`OR1200_DCINDXH:`OR1200_DCLS] :

                    dc_addr[`OR1200_DCINDXH:`OR1200_DCLS];

assign dctag_en = dc_block_invalidate | dc_en;

assign dctag_v = dc_block_invalidate ? 1'b0 : dcfsm_tag_valid;

assign dctag_dirty = dc_block_invalidate ? 1'b0 : dcfsm_tag_dirty;

//

// Data to BIU is from DCRAM when bursting lines back into memory

//

assign dcsb_dat_o = dcfsm_biu_do_sel ? from_dcram : dcqmem_dat_i;

//

// Bypases of the DC when DC is disabled

//

assign dcsb_cyc_o = (dc_en) ?

                    dcfsm_biu_read | dcfsm_biu_write : dcqmem_cycstb_i;

assign dcsb_stb_o = (dc_en) ?

                    dcfsm_biu_read | dcfsm_biu_write : dcqmem_cycstb_i;

assign dcsb_we_o = (dc_en) ?

                   dcfsm_biu_write : dcqmem_we_i;

assign dcsb_sel_o = (dc_en & dcfsm_burst) ?

                    4'b1111 : dcqmem_sel_i;

assign dcsb_cab_o = dc_en & dcfsm_burst & dcsb_cyc_o;

assign dcqmem_rty_o = ~dcqmem_ack_o;

assign dcqmem_tag_o = dcqmem_err_o ? `OR1200_DTAG_BE : dcqmem_tag_i;

//

// DC/LSU normal and error termination

//

assign dcqmem_ack_o = dc_en ?

                      dcfsm_first_hit_ack | dcfsm_first_miss_ack : dcsb_ack_i;

assign dcqmem_err_o = dc_en ? dcfsm_first_miss_err : dcsb_err_i;

//

// Select between input data generated by LSU or by BIU

//

assign to_dcram = (dcfsm_dcram_di_sel) ? dcsb_dat_i : dcqmem_dat_i;

//

// Select between data generated by DCRAM or passed by BIU

//

assign dcqmem_dat_o = dcfsm_first_miss_ack | !dc_en ? dcsb_dat_i : from_dcram;

//

// Tag comparison

//

wire [31:`OR1200_DCTAGL]  dcqmem_adr_i_tag;

assign dcqmem_adr_i_tag = dcqmem_adr_i[31:`OR1200_DCTAGL];

/*

always @(tag or dcqmem_adr_i_tag or tag_v) begin

        if ((tag != dcqmem_adr_i_tag) || !tag_v

`ifdef OR1200_RAM_PARITY

              | p_err

`endif

)

                tagcomp_miss = 1'b1;

        else

                tagcomp_miss = 1'b0;

end

*/

assign tagcomp_miss = (tag != dcqmem_adr_i_tag) | !tag_v

`ifdef OR1200_RAM_PARITY

                       | (|p_err_wire)

`endif

                       ;

//

// Instantiation of DC Finite State Machine

//

or1200_dc_fsm or1200_dc_fsm(

        .clk(clk),

        .rst(rst),

        .dc_en(dc_en),

        .dcqmem_cycstb_i(dcqmem_cycstb_i),

        .dcqmem_ci_i(dcqmem_ci_i),

        .dcqmem_we_i(dcqmem_we_i),

        .dcqmem_sel_i(dcqmem_sel_i),

        .tagcomp_miss(tagcomp_miss),

        .tag(tag),

        .tag_v(tag_v),

        .dirty(dirty),

        .biudata_valid(dcsb_ack_i),

        .biudata_error(dcsb_err_i),

        .lsu_addr(dcqmem_adr_i),

        .dcram_we(dcram_we),

        .biu_read(dcfsm_biu_read),

        .biu_write(dcfsm_biu_write),

        .dcram_di_sel(dcfsm_dcram_di_sel),

        .biu_do_sel(dcfsm_biu_do_sel),

        .first_hit_ack(dcfsm_first_hit_ack),

        .first_miss_ack(dcfsm_first_miss_ack),

        .first_miss_err(dcfsm_first_miss_err),

        .burst(dcfsm_burst),

        .tag_we(dcfsm_tag_we),

        .tag_valid(dcfsm_tag_valid),

        .tag_dirty(dcfsm_tag_dirty),

        .dc_addr(dc_addr),

        .dc_no_writethrough(dc_no_writethrough),

        .dc_block_flush(dc_block_flush),

        .dc_block_writeback(dc_block_writeback),

        .spr_dat_i(spr_dat_i),

        .mtspr_dc_done(mtspr_dc_done),

        .spr_cswe(spr_cs & spr_write)

);

//

// Instantiation of DC main memory

//

or1200_dc_ram or1200_dc_ram(

        .clk(clk),

        .rst(rst),

`ifdef OR1200_BIST

        // RAM BIST

        .mbist_si_i(mbist_ram_si),

        .mbist_so_o(mbist_ram_so),

        .mbist_ctrl_i(mbist_ctrl_i),

`endif

`ifdef OR1200_RAM_PARITY

        .p_err(p_err_wire[0]),

`endif

        .addr(dc_addr[`OR1200_DCINDXH:2]),

        .en(dc_en),

        .we(dcram_we),

        .datain(to_dcram),

        .dataout(from_dcram)

);

//

// Instantiation of DC TAG memory

//

or1200_dc_tag or1200_dc_tag(

        .clk(clk),

        .rst(rst),

`ifdef OR1200_BIST

        // RAM BIST

        .mbist_si_i(mbist_tag_si),

        .mbist_so_o(mbist_tag_so),

        .mbist_ctrl_i(mbist_ctrl_i),

`endif

`ifdef OR1200_RAM_PARITY

        .p_err(p_err_wire[1]),

`endif

        .addr(dctag_addr),

        .en(dctag_en),

        .we(dctag_we),

        .datain({dc_addr[31:`OR1200_DCTAGL], dctag_v, dctag_dirty}),

        .tag_v(tag_v),

        .tag(tag),

        .dirty(dirty)

);

`endif // !`ifdef OR1200_NO_DC

endmodule