///////////////////////////////////////////
// DCacheFlushFSM.sv
//
// Written: David Harris David_Harris@hmc.edu and Rose Thompson rose@rosethompson.net
// Modified: 14 June 2023
//
// Purpose: The L1 data cache and any feature L2 or high cache will not necessary writeback all dirty
// line before the end of test. Signature based regression tests need to check the L1 data cache
// in addition to the main memory. These modules create a shadow memory with a projection of the
// D$ contents.
//
// A component of the Wally configurable RISC-V project.
//
// Copyright (C) 2021 Harvey Mudd College & Oklahoma State University
//
// SPDX-License-Identifier: Apache-2.0 WITH SHL-2.1
//
// Licensed under the Solderpad Hardware License v 2.1 (the “License”); you may not use this file
// except in compliance with the License, or, at your option, the Apache License version 2.0. You
// may obtain a copy of the License at
//
// https://solderpad.org/licenses/SHL-2.1/
//
// Unless required by applicable law or agreed to in writing, any work distributed under the
// License is distributed on an “AS IS” BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,
// either express or implied. See the License for the specific language governing permissions
// and limitations under the License.
////////////////////////////////////////////////////////////////////////////////////////////////
module DCacheFlushFSM import cvw::*; #(parameter cvw_t P)
(input logic clk,
input logic start,
output logic done);
genvar adr;
logic [P.XLEN-1:0] ShadowRAM[P.UNCORE_RAM_BASE>>(1+P.XLEN/32):(P.UNCORE_RAM_RANGE+P.UNCORE_RAM_BASE)>>1+(P.XLEN/32)];
logic startD;
if(P.DCACHE_SUPPORTED) begin
localparam numlines = P.DCACHE_WAYSIZEINBYTES*8/P.DCACHE_LINELENINBITS;
localparam numways = P.DCACHE_NUMWAYS;
localparam linelen = P.DCACHE_LINELENINBITS;
localparam linebytelen = linelen/8;
localparam sramlen = P.CACHE_SRAMLEN;
localparam cachesramwords = linelen/sramlen;
localparam numwords = sramlen/P.XLEN;
localparam lognumlines = $clog2(numlines);
localparam loglinebytelen = $clog2(linebytelen);
localparam lognumways = $clog2(numways);
localparam tagstart = lognumlines + loglinebytelen;
genvar index, way, cacheWord;
logic [sramlen-1:0] CacheData [numways-1:0] [numlines-1:0] [cachesramwords-1:0];
logic [sramlen-1:0] cacheline;
logic [P.XLEN-1:0] CacheTag [numways-1:0] [numlines-1:0] [cachesramwords-1:0];
logic CacheValid [numways-1:0] [numlines-1:0] [cachesramwords-1:0];
logic CacheDirty [numways-1:0] [numlines-1:0] [cachesramwords-1:0];
logic [P.PA_BITS-1:0] CacheAdr [numways-1:0] [numlines-1:0] [cachesramwords-1:0];
for(index = 0; index < numlines; index++) begin
for(way = 0; way < numways; way++) begin
for(cacheWord = 0; cacheWord < cachesramwords; cacheWord++) begin
copyShadow #(.P(P), .tagstart(tagstart),
.loglinebytelen(loglinebytelen), .sramlen(sramlen))
copyShadow(.clk,
.start,
.tag(testbench.dut.core.lsu.bus.dcache.dcache.CacheWays[way].CacheTagMem.ram.RAM[index][P.PA_BITS-1-tagstart:0]),
.valid(testbench.dut.core.lsu.bus.dcache.dcache.CacheWays[way].ValidBits[index]),
.dirty(testbench.dut.core.lsu.bus.dcache.dcache.CacheWays[way].DirtyBits[index]),
// these dirty bit selections would be needed if dirty is moved inside the tag array.
//.dirty(testbench.dut.core.lsu.bus.dcache.dcache.CacheWays[way].dirty.DirtyMem.RAM[index]),
//.dirty(testbench.dut.core.lsu.bus.dcache.dcache.CacheWays[way].CacheTagMem.RAM[index][P.PA_BITS+tagstart]),
.data(testbench.dut.core.lsu.bus.dcache.dcache.CacheWays[way].word[cacheWord].wordram.CacheDataMem.ram.RAM[index]),
.index(index),
.cacheWord(cacheWord),
.CacheData(CacheData[way][index][cacheWord]),
.CacheAdr(CacheAdr[way][index][cacheWord]),
.CacheTag(CacheTag[way][index][cacheWord]),
.CacheValid(CacheValid[way][index][cacheWord]),
.CacheDirty(CacheDirty[way][index][cacheWord]));
end
end
end
integer i, j, k, l;
always @(posedge clk) begin
if (startD) begin
for(i = 0; i < numlines; i++) begin
for(j = 0; j < numways; j++) begin
for(l = 0; l < cachesramwords; l++) begin
if (CacheValid[j][i][l] & CacheDirty[j][i][l]) begin
for(k = 0; k < numwords; k++) begin
//cacheline = CacheData[j][i][0];
// does not work with modelsim
// # ** Error: ../testbench/testbench.sv(483): Range must be bounded by constant expressions.
// see https://verificationacademy.com/forums/systemverilog/range-must-be-bounded-constant-expressions
//ShadowRAM[CacheAdr[j][i][k] >> $clog2(P.XLEN/8)] = cacheline[P.XLEN*(k+1)-1:P.XLEN*k];
/* verilator lint_off WIDTHTRUNC */
// avoid lint error: address trunc warning for shadowram index
ShadowRAM[(CacheAdr[j][i][l] >> $clog2(P.XLEN/8)) + {{{P.PA_BITS-32}{1'b0}}, k}] = CacheData[j][i][l][P.XLEN*k +: P.XLEN];
/* verilator lint_on WIDTHTRUNC */
end
end
end
end
end
end
end
end
flop #(1) doneReg1(.clk, .d(start), .q(startD));
flop #(1) doneReg2(.clk, .d(startD), .q(done));
endmodule
module copyShadow import cvw::*; #(parameter cvw_t P,
parameter tagstart, loglinebytelen, sramlen)
(input logic clk,
input logic start,
input logic [P.PA_BITS-1:tagstart] tag,
input logic valid, dirty,
input logic [sramlen-1:0] data,
input logic [32-1:0] index,
input logic [32-1:0] cacheWord,
output logic [sramlen-1:0] CacheData,
output logic [P.PA_BITS-1:0] CacheAdr,
output logic [P.XLEN-1:0] CacheTag,
output logic CacheValid,
output logic CacheDirty);
logic [P.XLEN+1:0] TagExtend;
logic [P.XLEN+1:0] IndexExtend;
logic [P.XLEN+1:0] CacheWordExtend;
logic [P.XLEN+1:0] CacheAdrExtend;
assign TagExtend = {{{P.XLEN-(P.PA_BITS-tagstart)+2}{1'b0}}, tag};
assign IndexExtend = {{{P.XLEN-32+2}{1'b0}}, index};
assign CacheWordExtend = {{{P.XLEN-32+2}{1'b0}}, cacheWord};
always_ff @(posedge clk) begin
if(start) begin
CacheTag = TagExtend[P.XLEN-1:0];
CacheValid = valid;
CacheDirty = dirty;
CacheData = data;
CacheAdrExtend = (TagExtend << tagstart) + (IndexExtend << loglinebytelen) + (CacheWordExtend << $clog2(sramlen/8));
end
end
assign CacheAdr = CacheAdrExtend[P.PA_BITS-1:0];
endmodule