Cache code cleanup

This commit is contained in:
David Harris 2023-01-07 15:44:44 -08:00
parent 0a25f18a07
commit 057183bcc9

View File

@ -145,32 +145,34 @@ module cache #(parameter LINELEN, NUMLINES, NUMWAYS, LOGBWPL, WORDLEN, MUXINTE
// Bypass cache array to save a cycle when finishing a load miss
mux2 #(LINELEN) EarlyReturnMux(ReadDataLineCache, FetchBuffer, SelFetchBuffer, ReadDataLine);
// Select word from cache line
subcachelineread #(LINELEN, WORDLEN, MUXINTERVAL) subcachelineread(
.PAdr(WordOffsetAddr),
.ReadDataLine, .ReadDataWord);
.PAdr(WordOffsetAddr), .ReadDataLine, .ReadDataWord);
/////////////////////////////////////////////////////////////////////////////////////////////
// Write Path: Write data and address. Muxes between writes from bus and writes from CPU.
/////////////////////////////////////////////////////////////////////////////////////////////
onehotdecoder #(LOGCWPL) adrdec(
.bin(PAdr[LOGCWPL+LOGLLENBYTES-1:LOGLLENBYTES]), .decoded(MemPAdrDecoded));
for(index = 0; index < 2**LOGCWPL; index++) begin
assign DemuxedByteMask[(index+1)*(WORDLEN/8)-1:index*(WORDLEN/8)] = MemPAdrDecoded[index] ? ByteMask : '0;
end
assign FetchBufferByteSel = SetValid & ~SetDirty ? '1 : ~DemuxedByteMask; // If load miss set all muxes to 1.
assign LineByteMask = SetValid ? '1 : SetDirty ? DemuxedByteMask : '0;
for(index = 0; index < LINELEN/8; index++) begin
mux2 #(8) WriteDataMux(.d0(CacheWriteData[(8*index)%WORDLEN+7:(8*index)%WORDLEN]),
.d1(FetchBuffer[8*index+7:8*index]), .s(FetchBufferByteSel[index]), .y(LineWriteData[8*index+7:8*index]));
end
// Bus address for fetch, writeback, or flush writeback
mux3 #(`PA_BITS) CacheBusAdrMux(.d0({PAdr[`PA_BITS-1:OFFSETLEN], {OFFSETLEN{1'b0}}}),
.d1({Tag, PAdr[SETTOP-1:OFFSETLEN], {OFFSETLEN{1'b0}}}),
.d2({Tag, FlushAdr, {OFFSETLEN{1'b0}}}),
.s({SelFlush, SelWriteback}), .y(CacheBusAdr));
/////////////////////////////////////////////////////////////////////////////////////////////
// Write Path
/////////////////////////////////////////////////////////////////////////////////////////////
// Adjust byte mask from word to cache line
onehotdecoder #(LOGCWPL) adrdec(.bin(PAdr[LOGCWPL+LOGLLENBYTES-1:LOGLLENBYTES]), .decoded(MemPAdrDecoded));
for(index = 0; index < 2**LOGCWPL; index++) begin
assign DemuxedByteMask[(index+1)*(WORDLEN/8)-1:index*(WORDLEN/8)] = MemPAdrDecoded[index] ? ByteMask : '0;
end
assign FetchBufferByteSel = SetValid & ~SetDirty ? '1 : ~DemuxedByteMask; // If load miss set all muxes to 1.
assign LineByteMask = SetValid ? '1 : SetDirty ? DemuxedByteMask : '0;
// Merge write data into fetched cache line for store miss
for(index = 0; index < LINELEN/8; index++) begin
mux2 #(8) WriteDataMux(.d0(CacheWriteData[(8*index)%WORDLEN+7:(8*index)%WORDLEN]),
.d1(FetchBuffer[8*index+7:8*index]), .s(FetchBufferByteSel[index]), .y(LineWriteData[8*index+7:8*index]));
end
/////////////////////////////////////////////////////////////////////////////////////////////
// Flush address and way generation during flush
/////////////////////////////////////////////////////////////////////////////////////////////
@ -189,15 +191,13 @@ module cache #(parameter LINELEN, NUMLINES, NUMWAYS, LOGBWPL, WORDLEN, MUXINTE
/////////////////////////////////////////////////////////////////////////////////////////////
// Cache FSM
/////////////////////////////////////////////////////////////////////////////////////////////
cachefsm cachefsm(.clk, .reset, .CacheBusRW, .CacheBusAck,
.FlushStage, .CacheRW, .CacheAtomic, .Stall,
.CacheHit, .LineDirty, .CacheStall, .CacheCommitted,
.CacheMiss, .CacheAccess, .SelAdr,
.ClearValid, .ClearDirty, .SetDirty,
.SetValid, .SelWriteback, .SelFlush,
.ClearValid, .ClearDirty, .SetDirty, .SetValid, .SelWriteback, .SelFlush,
.FlushAdrCntEn, .FlushWayCntEn, .FlushCntRst,
.FlushAdrFlag, .FlushWayFlag, .FlushCache, .SelFetchBuffer,
.InvalidateCache,
.CacheEn,
.LRUWriteEn);
.InvalidateCache, .CacheEn, .LRUWriteEn);
endmodule