Simplified Dcache by sharing the read data mux with the victim selection mux.

This commit is contained in:
Ross Thompson 2021-08-11 16:55:55 -05:00
parent 22f274c51e
commit 4b25fed6d8

View File

@ -97,9 +97,8 @@ module dcache
logic SetDirtyM, ClearDirtyM;
logic [BLOCKLEN-1:0] ReadDataBlockWayM [NUMWAYS-1:0];
logic [BLOCKLEN-1:0] ReadDataBlockWayMaskedM [NUMWAYS-1:0];
logic [BLOCKLEN-1:0] VictimReadDataBLockWayMaskedM [NUMWAYS-1:0];
logic [TAGLEN-1:0] ReadTag [NUMWAYS-1:0];
logic [NUMWAYS-1:0] Valid, Dirty, WayHit;
logic [NUMWAYS-1:0] Valid, Dirty, WayHit, SelectedWay;
logic CacheHit;
logic [NUMWAYS-2:0] ReplacementBits [NUMLINES-1:0];
logic [NUMWAYS-2:0] BlockReplacementBits;
@ -242,12 +241,10 @@ module dcache
.Valid(Valid[way]),
.Dirty(Dirty[way]));
assign WayHit[way] = Valid[way] & (ReadTag[way] == MemPAdrM[`PA_BITS-1:OFFSETLEN+INDEXLEN]);
assign ReadDataBlockWayMaskedM[way] = WayHit[way] ? ReadDataBlockWayM[way] : '0; // first part of AO mux.
assign SelectedWay[way] = SelEvict ? VictimWay[way] : WayHit[way];
assign ReadDataBlockWayMaskedM[way] = SelectedWay[way] ? ReadDataBlockWayM[way] : '0; // first part of AO mux.
// the cache block candiate for eviction
// *** this should be sharable with the read data muxing, but for now i'm doing the simple
// thing and making them separate.
assign VictimReadDataBLockWayMaskedM[way] = VictimWay[way] ? ReadDataBlockWayM[way] : '0;
assign VictimDirtyWay[way] = VictimWay[way] & Dirty[way] & Valid[way];
assign VictimTagWay[way] = VictimWay[way] ? ReadTag[way] : '0;
end
@ -301,7 +298,6 @@ module dcache
VictimTag = '0;
for(int index = 0; index < NUMWAYS; index++) begin
ReadDataBlockM = ReadDataBlockM | ReadDataBlockWayMaskedM[index];
VictimReadDataBlockM = VictimReadDataBlockM | VictimReadDataBLockWayMaskedM[index];
VictimTag = VictimTag | VictimTagWay[index];
end
end
@ -314,7 +310,6 @@ module dcache
generate
for (index = 0; index < WORDSPERLINE; index++) begin
assign ReadDataBlockSetsM[index] = ReadDataBlockM[((index+1)*`XLEN)-1: (index*`XLEN)];
assign VictimReadDataBlockSetsM[index] = VictimReadDataBlockM[((index+1)*`XLEN)-1: (index*`XLEN)];
end
endgenerate
@ -322,7 +317,7 @@ module dcache
assign ReadDataWordM = ReadDataBlockSetsM[MemPAdrM[$clog2(WORDSPERLINE+`XLEN/8) : $clog2(`XLEN/8)]];
assign HWDATA = CacheableM ? VictimReadDataBlockSetsM[FetchCount] : WriteDataM;
assign HWDATA = CacheableM ? ReadDataBlockSetsM[FetchCount] : WriteDataM;
mux2 #(`XLEN) UnCachedDataMux(.d0(ReadDataWordM),
.d1(DCacheMemWriteData[`XLEN-1:0]),