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

////                                                              ////

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

////                                                              ////

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

////  http://www.opencores.org/cores/or1k/                        ////

////                                                              ////

////  Description                                                 ////

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

////                                                              ////

////  To Do:                                                      ////

////   - make it smaller and faster                               ////

////                                                              ////

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

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

////                                                              ////

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

////                                                              ////

//// Copyright (C) 2000 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                     ////

////                                                              ////

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

//

// CVS Revision History

//

// $Log: not supported by cvs2svn $

// Revision 1.3  2002/01/28 01:16:00  lampret

// Changed 'void' nop-ops instead of insn[0] to use insn[16]. Debug unit stalls the tick timer. Prepared new flag generation for add and and insns. Blocked DC/IC while they are turned off. Fixed I/D MMU SPRs layout except WAYs. TODO: smart IC invalidate, l.j 2 and TLB ways.

//

// Revision 1.2  2002/01/14 06:18:22  lampret

// Fixed mem2reg bug in FAST implementation. Updated debug unit to work with new genpc/if.

//

// Revision 1.1  2002/01/03 08:16:15  lampret

// New prefixes for RTL files, prefixed module names. Updated cache controllers and MMUs.

//

// Revision 1.10  2001/10/21 17:57:16  lampret

// Removed params from generic_XX.v. Added translate_off/on in sprs.v and id.v. Removed spr_addr from dc.v and ic.v. Fixed CR+LF.

//

// Revision 1.9  2001/10/14 13:12:09  lampret

// MP3 version.

//

// Revision 1.1.1.1  2001/10/06 10:18:35  igorm

// no message

//

// Revision 1.4  2001/08/13 03:36:20  lampret

// Added cfg regs. Moved all defines into one defines.v file. More cleanup.

//

// Revision 1.3  2001/08/09 13:39:33  lampret

// Major clean-up.

//

// Revision 1.2  2001/07/22 03:31:53  lampret

// Fixed RAM's oen bug. Cache bypass under development.

//

// Revision 1.1  2001/07/20 00:46:03  lampret

// Development version of RTL. Libraries are missing.

//

//

// 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

        dcbiu_dat_o, dcbiu_adr_o, dcbiu_cyc_o, dcbiu_stb_o, dcbiu_we_o, dcbiu_sel_o, dcbiu_cab_o,

        dcbiu_dat_i, dcbiu_ack_i, dcbiu_err_i,

        // Internal i/f

        dc_en,

        dcdmmu_adr_i, dcdmmu_cycstb_i, dcdmmu_ci_i,

        dcpu_we_i, dcpu_sel_i, dcpu_tag_i, dcpu_dat_i,

        dcpu_dat_o, dcpu_ack_o, dcpu_rty_o, dcdmmu_err_o, dcdmmu_tag_o,

        // SPRs

        spr_cs, spr_write, spr_dat_i

);

parameter dw = `OR1200_OPERAND_WIDTH;

//

// I/O

//

//

// Clock and reset

//

input                           clk;

input                           rst;

//

// External I/F

//

output  [dw-1:0]         dcbiu_dat_o;

output  [31:0]                   dcbiu_adr_o;

output                          dcbiu_cyc_o;

output                          dcbiu_stb_o;

output                          dcbiu_we_o;

output  [3:0]                    dcbiu_sel_o;

output                          dcbiu_cab_o;

input   [dw-1:0]         dcbiu_dat_i;

input                           dcbiu_ack_i;

input                           dcbiu_err_i;

//

// Internal I/F

//

input                           dc_en;

input   [31:0]                   dcdmmu_adr_i;

input                           dcdmmu_cycstb_i;

input                           dcdmmu_ci_i;

input                           dcpu_we_i;

input   [3:0]                    dcpu_sel_i;

input   [3:0]                    dcpu_tag_i;

input   [dw-1:0]         dcpu_dat_i;

output  [dw-1:0]         dcpu_dat_o;

output                          dcpu_ack_o;

output                          dcpu_rty_o;

output                          dcdmmu_err_o;

output  [3:0]                    dcdmmu_tag_o;

//

// SPR access

//

input                           spr_cs;

input                           spr_write;

input   [31:0]                   spr_dat_i;

//

// Internal wires and regs

//

wire                            tag_v;

wire    [`OR1200_DCTAG_W-2:0]    tag;

wire    [dw-1:0]         to_dcram;

wire    [dw-1:0]         from_dcram;

wire    [31:0]                   saved_addr;

wire    [3:0]                    dcram_we;

wire                            dctag_we;

wire    [31:0]                   dc_addr;

wire                            dcfsm_biu_read;

wire                            dcfsm_biu_write;

reg                             tagcomp_miss;

wire    [`OR1200_DCINDXH:`OR1200_DCLS]  dctag_addr;

wire                            dctag_en;

wire                            dctag_v;

wire                            dc_inv;

wire                            dcfsm_first_hit_ack;

wire                            dcfsm_first_miss_ack;

wire                            dcfsm_first_miss_err;

wire                            dcfsm_burst;

wire                            dcfsm_tag_we;

//

// Simple assignments

//

assign dcbiu_adr_o = dc_addr;

assign dc_inv = spr_cs & spr_write;

assign dctag_we = dcfsm_tag_we | dc_inv;

assign dctag_addr = dc_inv ? spr_dat_i[`OR1200_DCINDXH:`OR1200_DCLS] : dc_addr[`OR1200_DCINDXH:`OR1200_DCLS];

assign dctag_en = dc_inv | dc_en;

assign dctag_v = ~dc_inv;

//

// Data to BIU is from DCRAM when DC is enabled or from LSU when

// DC is disabled

//

assign dcbiu_dat_o = dcpu_dat_i;

//

// Bypases of the DC when DC is disabled

//

assign dcbiu_cyc_o = (dc_en) ? dcfsm_biu_read | dcfsm_biu_write : dcdmmu_cycstb_i;

assign dcbiu_stb_o = (dc_en) ? dcfsm_biu_read | dcfsm_biu_write : dcdmmu_cycstb_i;

assign dcbiu_we_o = (dc_en) ? dcfsm_biu_write : dcpu_we_i;

assign dcbiu_sel_o = (dc_en & dcfsm_biu_read & !dcfsm_biu_write & !dcdmmu_ci_i) ? 4'b1111 : dcpu_sel_i;

assign dcbiu_cab_o = (dc_en) ? dcfsm_burst : 1'b0;

assign dcpu_rty_o = ~dcpu_ack_o;

assign dcdmmu_tag_o = dcdmmu_err_o ? `OR1200_DTAG_BE : dcpu_tag_i;

//

// DC/LSU normal and error termination

//

assign dcpu_ack_o = dc_en ? dcfsm_first_hit_ack | dcfsm_first_miss_ack : dcbiu_ack_i;

assign dcdmmu_err_o = dc_en ? dcfsm_first_miss_err : dcbiu_err_i;

//

// Select between claddr generated by DC FSM and addr[3:2] generated by LSU

//

//assign dc_addr = (dcfsm_biu_read | dcfsm_biu_write) ? saved_addr : dcdmmu_adr_i;

//

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

//

assign to_dcram = (dcfsm_biu_read) ? dcbiu_dat_i : dcpu_dat_i;

//

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

//

assign dcpu_dat_o = dcfsm_first_miss_ack | !dc_en ? dcbiu_dat_i : from_dcram;

//

// Tag comparison

//

always @(tag or saved_addr or tag_v) begin

        if ((tag != saved_addr[31:`OR1200_DCTAGL]) || !tag_v)

                tagcomp_miss = 1'b1;

        else

                tagcomp_miss = 1'b0;

end

//

// Instantiation of DC Finite State Machine

//

or1200_dc_fsm or1200_dc_fsm(

        .clk(clk),

        .rst(rst),

        .dc_en(dc_en),

        .dcdmmu_cycstb_i(dcdmmu_cycstb_i),

        .dcdmmu_ci_i(dcdmmu_ci_i),

        .dcpu_we_i(dcpu_we_i),

        .dcpu_sel_i(dcpu_sel_i),

        .tagcomp_miss(tagcomp_miss),

        .biudata_valid(dcbiu_ack_i),

        .biudata_error(dcbiu_err_i),

        .start_addr(dcdmmu_adr_i),

        .saved_addr(saved_addr),

        .dcram_we(dcram_we),

        .biu_read(dcfsm_biu_read),

        .biu_write(dcfsm_biu_write),

        .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),

        .dc_addr(dc_addr)

);

//

// Instantiation of DC main memory

//

or1200_dc_ram or1200_dc_ram(

        .clk(clk),

        .rst(rst),

        .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),

        .addr(dctag_addr),

        .en(dctag_en),

        .we(dctag_we),

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

        .tag_v(tag_v),

        .tag(tag)

);

endmodule