Renamed RW signals through the caches, bus interfaces, and IFU/LSU.

CPU to $ is called LSURWM or IFURWF.
CPU to Bus is called BusRW
$ to Bus is called CacheBusRW.
This commit is contained in:
Ross Thompson 2022-09-23 11:46:53 -05:00
parent 6a6686a34b
commit dcc00ef4b3
9 changed files with 93 additions and 97 deletions

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@ -54,8 +54,7 @@ module cache #(parameter LINELEN, NUMLINES, NUMWAYS, LOGBWPL, WORDLEN, MUXINTE
input logic Cacheable,
input logic SelReplay,
// Bus fsm interface
output logic CacheFetchLine,
output logic CacheWriteLine,
output logic [1:0] CacheBusRW,
input logic CacheBusAck,
input logic SelBusWord,
input logic [LOGBWPL-1:0] WordCount,
@ -212,7 +211,7 @@ module cache #(parameter LINELEN, NUMLINES, NUMWAYS, LOGBWPL, WORDLEN, MUXINTE
/////////////////////////////////////////////////////////////////////////////////////////////
assign CacheRW = Cacheable ? RW : 2'b00;
assign CacheAtomic = Cacheable ? Atomic : 2'b00;
cachefsm cachefsm(.clk, .reset, .CacheFetchLine, .CacheWriteLine, .CacheBusAck,
cachefsm cachefsm(.clk, .reset, .CacheBusRW, .CacheBusAck,
.CacheRW, .CacheAtomic, .CPUBusy, .IgnoreRequestTLB, .TrapM,
.CacheHit, .VictimDirty, .CacheStall, .CacheCommitted,
.CacheMiss, .CacheAccess, .SelAdr,

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@ -58,8 +58,7 @@ module cachefsm
output logic CacheAccess,
// Bus outputs
output logic CacheCommitted,
output logic CacheWriteLine,
output logic CacheFetchLine,
output logic [1:0] CacheBusRW,
// dcache internals
output logic SelAdr,
@ -194,8 +193,8 @@ module cachefsm
assign FlushAdrCntRst = (CurrState == STATE_READY);
assign FlushWayCntRst = (CurrState == STATE_READY) | (CurrState == STATE_FLUSH_INCR);
// Bus interface controls
assign CacheFetchLine = (CurrState == STATE_READY & DoAnyMiss) | (CurrState == STATE_MISS_FETCH_WDV & ~CacheBusAck);
assign CacheWriteLine = (CurrState == STATE_MISS_FETCH_WDV & CacheBusAck & VictimDirty) |
assign CacheBusRW[1] = (CurrState == STATE_READY & DoAnyMiss) | (CurrState == STATE_MISS_FETCH_WDV & ~CacheBusAck);
assign CacheBusRW[0] = (CurrState == STATE_MISS_FETCH_WDV & CacheBusAck & VictimDirty) |
(CurrState == STATE_MISS_EVICT_DIRTY & ~CacheBusAck) |
(CurrState == STATE_FLUSH_WRITE_BACK & ~CacheBusAck) |
(CurrState == STATE_FLUSH_CHECK & VictimDirty);

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@ -50,14 +50,14 @@ module ahbcacheinterface #(parameter WORDSPERLINE, LINELEN, LOGWPL, CACHE_ENABLE
// cache interface
input logic [`PA_BITS-1:0] CacheBusAdr,
input logic [1:0] CacheRW,
input logic [1:0] CacheBusRW,
output logic CacheBusAck,
output logic [LINELEN-1:0] FetchBuffer,
output logic SelUncachedAdr,
// lsu/ifu interface
input logic [`PA_BITS-1:0] PAdr,
input logic [1:0] RW,
input logic [1:0] BusRW,
input logic CPUBusy,
input logic [2:0] Funct3,
output logic SelBusWord,
@ -83,7 +83,7 @@ module ahbcacheinterface #(parameter WORDSPERLINE, LINELEN, LOGWPL, CACHE_ENABLE
mux2 #(3) sizemux(.d0(`XLEN == 32 ? 3'b010 : 3'b011), .d1(Funct3), .s(SelUncachedAdr), .y(HSIZE));
buscachefsm #(WordCountThreshold, LOGWPL, CACHE_ENABLED) AHBBuscachefsm(
.HCLK, .HRESETn, .RW, .CPUBusy, .BusCommitted, .BusStall, .CaptureEn, .SelBusWord,
.CacheRW, .CacheBusAck, .SelUncachedAdr, .WordCount, .WordCountDelayed,
.HCLK, .HRESETn, .BusRW, .CPUBusy, .BusCommitted, .BusStall, .CaptureEn, .SelBusWord,
.CacheBusRW, .CacheBusAck, .SelUncachedAdr, .WordCount, .WordCountDelayed,
.HREADY, .HTRANS, .HWRITE, .HBURST);
endmodule

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@ -47,7 +47,7 @@ module ahbinterface #(parameter LSU = 0) // **** modify to use LSU/ifu parameter
output logic [`XLEN/8-1:0] HWSTRB,
// lsu/ifu interface
input logic [1:0] RW,
input logic [1:0] BusRW,
input logic [`XLEN/8-1:0] ByteMask,
input logic [`XLEN-1:0] WriteData,
input logic CPUBusy,
@ -71,7 +71,7 @@ module ahbinterface #(parameter LSU = 0) // **** modify to use LSU/ifu parameter
assign HWSTRB = '0;
end
busfsm busfsm(.HCLK, .HRESETn, .RW,
busfsm busfsm(.HCLK, .HRESETn, .BusRW,
.BusCommitted, .CPUBusy, .BusStall, .CaptureEn, .HREADY,
.HTRANS, .HWRITE);
endmodule

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@ -38,14 +38,14 @@ module buscachefsm #(parameter integer WordCountThreshold,
input logic HRESETn,
// IEU interface
input logic [1:0] RW,
input logic [1:0] BusRW,
input logic CPUBusy,
output logic BusCommitted,
output logic BusStall,
output logic CaptureEn,
// cache interface
input logic [1:0] CacheRW,
input logic [1:0] CacheBusRW,
output logic CacheBusAck,
// lsu interface
@ -83,21 +83,21 @@ module buscachefsm #(parameter integer WordCountThreshold,
always_comb begin
case(CurrState)
ADR_PHASE: if(HREADY & |RW) NextState = DATA_PHASE;
else if (HREADY & CacheRW[0]) NextState = CACHE_EVICT;
else if (HREADY & CacheRW[1]) NextState = CACHE_FETCH;
ADR_PHASE: if(HREADY & |BusRW) NextState = DATA_PHASE;
else if (HREADY & CacheBusRW[0]) NextState = CACHE_EVICT;
else if (HREADY & CacheBusRW[1]) NextState = CACHE_FETCH;
else NextState = ADR_PHASE;
DATA_PHASE: if(HREADY) NextState = MEM3;
else NextState = DATA_PHASE;
MEM3: if(CPUBusy) NextState = MEM3;
else NextState = ADR_PHASE;
CACHE_FETCH: if(HREADY & FinalWordCount & CacheRW[0]) NextState = CACHE_EVICT;
else if(HREADY & FinalWordCount & CacheRW[1]) NextState = CACHE_FETCH;
else if(HREADY & FinalWordCount & ~|CacheRW) NextState = ADR_PHASE;
CACHE_FETCH: if(HREADY & FinalWordCount & CacheBusRW[0]) NextState = CACHE_EVICT;
else if(HREADY & FinalWordCount & CacheBusRW[1]) NextState = CACHE_FETCH;
else if(HREADY & FinalWordCount & ~|CacheBusRW) NextState = ADR_PHASE;
else NextState = CACHE_FETCH;
CACHE_EVICT: if(HREADY & FinalWordCount & CacheRW[0]) NextState = CACHE_EVICT;
else if(HREADY & FinalWordCount & CacheRW[1]) NextState = CACHE_FETCH;
else if(HREADY & FinalWordCount & ~|CacheRW) NextState = ADR_PHASE;
CACHE_EVICT: if(HREADY & FinalWordCount & CacheBusRW[0]) NextState = CACHE_EVICT;
else if(HREADY & FinalWordCount & CacheBusRW[1]) NextState = CACHE_FETCH;
else if(HREADY & FinalWordCount & ~|CacheBusRW) NextState = ADR_PHASE;
else NextState = CACHE_EVICT;
default: NextState = ADR_PHASE;
endcase
@ -122,30 +122,30 @@ module buscachefsm #(parameter integer WordCountThreshold,
assign FinalWordCount = WordCountDelayed == WordCountThreshold[LOGWPL-1:0];
assign WordCntEn = ((NextState == CACHE_EVICT | NextState == CACHE_FETCH) & HREADY) |
(NextState == ADR_PHASE & |CacheRW & HREADY);
(NextState == ADR_PHASE & |CacheBusRW & HREADY);
assign WordCntReset = NextState == ADR_PHASE;
assign CaptureEn = (CurrState == DATA_PHASE & RW[1]) | (CurrState == CACHE_FETCH & HREADY);
assign CaptureEn = (CurrState == DATA_PHASE & BusRW[1]) | (CurrState == CACHE_FETCH & HREADY);
assign CacheAccess = CurrState == CACHE_FETCH | CurrState == CACHE_EVICT;
assign BusStall = (CurrState == ADR_PHASE & (|RW | |CacheRW)) |
//(CurrState == DATA_PHASE & ~RW[0]) | // replace the next line with this. Fails uart test but i think it's a test problem not a hardware problem.
assign BusStall = (CurrState == ADR_PHASE & (|BusRW | |CacheBusRW)) |
//(CurrState == DATA_PHASE & ~BusRW[0]) | // replace the next line with this. Fails uart test but i think it's a test problem not a hardware problem.
(CurrState == DATA_PHASE) |
(CurrState == CACHE_FETCH) |
(CurrState == CACHE_EVICT);
assign BusCommitted = CurrState != ADR_PHASE;
assign SelUncachedAdr = (CurrState == ADR_PHASE & |RW) |
assign SelUncachedAdr = (CurrState == ADR_PHASE & |BusRW) |
(CurrState == DATA_PHASE) |
(CurrState == MEM3);
// AHB bus interface
assign HTRANS = (CurrState == ADR_PHASE & HREADY & (|RW | |CacheRW)) |
assign HTRANS = (CurrState == ADR_PHASE & HREADY & (|BusRW | |CacheBusRW)) |
(CurrState == DATA_PHASE & ~HREADY) |
(CacheAccess & ~|WordCount & |CacheRW) ? AHB_NONSEQ :
(CacheAccess & ~|WordCount & |CacheBusRW) ? AHB_NONSEQ :
(CacheAccess & |WordCount) ? (`BURST_EN ? AHB_SEQ : AHB_NONSEQ) : AHB_IDLE;
assign HWRITE = RW[0] | CacheRW[0];
assign HBURST = `BURST_EN ? ((|CacheRW) ? LocalBurstType : 3'b0) : 3'b0; // this line is for burst.
assign HWRITE = BusRW[0] | CacheBusRW[0];
assign HBURST = `BURST_EN ? ((|CacheBusRW) ? LocalBurstType : 3'b0) : 3'b0; // this line is for burst.
always_comb begin
case(WordCountThreshold)
@ -159,8 +159,8 @@ module buscachefsm #(parameter integer WordCountThreshold,
// communication to cache
assign CacheBusAck = (CacheAccess & HREADY & FinalWordCount);
assign SelBusWord = (CurrState == ADR_PHASE & (RW[0] | CacheRW[0])) |
(CurrState == DATA_PHASE & RW[0]) |
assign SelBusWord = (CurrState == ADR_PHASE & (BusRW[0] | CacheBusRW[0])) |
(CurrState == DATA_PHASE & BusRW[0]) |
(CurrState == CACHE_EVICT) |
(CurrState == CACHE_FETCH);

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@ -36,7 +36,7 @@ module busfsm
input logic HRESETn,
// IEU interface
input logic [1:0] RW,
input logic [1:0] BusRW,
input logic CPUBusy,
output logic BusCommitted,
output logic BusStall,
@ -60,7 +60,7 @@ module busfsm
always_comb begin
case(CurrState)
ADR_PHASE: if(HREADY & |RW) NextState = DATA_PHASE;
ADR_PHASE: if(HREADY & |BusRW) NextState = DATA_PHASE;
else NextState = ADR_PHASE;
DATA_PHASE: if(HREADY) NextState = MEM3;
else NextState = DATA_PHASE;
@ -70,15 +70,15 @@ module busfsm
endcase
end
assign BusStall = (CurrState == ADR_PHASE & |RW) |
// (CurrState == DATA_PHASE & ~RW[0]); // possible optimization here. fails uart test, but i'm not sure the failure is valid.
assign BusStall = (CurrState == ADR_PHASE & |BusRW) |
// (CurrState == DATA_PHASE & ~BusRW[0]); // possible optimization here. fails uart test, but i'm not sure the failure is valid.
(CurrState == DATA_PHASE);
assign BusCommitted = CurrState != ADR_PHASE;
assign HTRANS = (CurrState == ADR_PHASE & HREADY & |RW) |
assign HTRANS = (CurrState == ADR_PHASE & HREADY & |BusRW) |
(CurrState == DATA_PHASE & ~HREADY) ? AHB_NONSEQ : AHB_IDLE;
assign HWRITE = RW[0];
assign HWRITE = BusRW[0];
assign CaptureEn = CurrState == DATA_PHASE;
endmodule

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@ -92,7 +92,7 @@ module ifu (
logic CompressedF;
logic [31:0] InstrRawD, InstrRawF;
logic [31:0] FinalInstrRawF;
logic [1:0] RWF;
logic [1:0] IFURWF;
logic [31:0] InstrE;
logic [`XLEN-1:0] PCD;
@ -186,11 +186,11 @@ module ifu (
// The IROM uses untranslated addresses, so it is not compatible with virtual memory.
if (`IROM_SUPPORTED) begin : irom
assign RWF = 2'b10;
assign IFURWF = 2'b10;
irom irom(.clk, .reset, .ce(~CPUBusy), .Adr(PCNextFSpill[`XLEN-1:0]), .ReadData(FinalInstrRawF));
end else begin
assign RWF = 2'b10;
assign IFURWF = 2'b10;
end
if (`BUS) begin : bus
localparam integer WORDSPERLINE = `ICACHE ? `ICACHE_LINELENINBITS/`XLEN : 1;
@ -201,24 +201,23 @@ module ifu (
logic [`PA_BITS-1:0] ICacheBusAdr;
logic ICacheBusAck;
logic SelUncachedAdr;
logic [1:0] CacheRW, RW;
logic [1:0] CacheBusRW, BusRW;
assign CacheRW = {ICacheFetchLine, 1'b0} & ~{ITLBMissF, ITLBMissF};
assign RW = RWF & ~{ITLBMissF, ITLBMissF} & ~{CacheableF, CacheableF};
assign BusRW = IFURWF & ~{ITLBMissF, ITLBMissF} & ~{CacheableF, CacheableF};
cache #(.LINELEN(`ICACHE_LINELENINBITS),
.NUMLINES(`ICACHE_WAYSIZEINBYTES*8/`ICACHE_LINELENINBITS),
.NUMWAYS(`ICACHE_NUMWAYS), .LOGBWPL(LOGBWPL), .WORDLEN(32), .MUXINTERVAL(16), .DCACHE(0))
icache(.clk, .reset, .CPUBusy, .IgnoreRequestTLB(ITLBMissF), .TrapM,
.FetchBuffer, .CacheBusAck(ICacheBusAck),
.CacheBusAdr(ICacheBusAdr), .CacheStall(ICacheStallF),
.CacheFetchLine(ICacheFetchLine),
.CacheWriteLine(), .ReadDataWord(FinalInstrRawF),
.CacheBusRW,
.ReadDataWord(FinalInstrRawF),
.Cacheable(CacheableF),
.SelReplay('0),
.CacheMiss(ICacheMiss), .CacheAccess(ICacheAccess),
.ByteMask('0), .WordCount('0), .SelBusWord('0),
.FinalWriteData('0),
.RW(RWF),
.RW(IFURWF),
.Atomic('0), .FlushCache('0),
.NextAdr(PCNextFSpill[11:0]),
.PAdr(PCPF),
@ -226,12 +225,12 @@ module ifu (
ahbcacheinterface #(WORDSPERLINE, LINELEN, LOGBWPL, `ICACHE)
ahbcacheinterface(.HCLK(clk), .HRESETn(~reset),
.HRDATA,
.CacheRW, .HSIZE(IFUHSIZE), .HBURST(IFUHBURST), .HTRANS(IFUHTRANS),
.CacheBusRW, .HSIZE(IFUHSIZE), .HBURST(IFUHBURST), .HTRANS(IFUHTRANS),
.Funct3(3'b010), .HADDR(IFUHADDR), .HREADY(IFUHREADY), .HWRITE(IFUHWRITE), .CacheBusAdr(ICacheBusAdr),
.WordCount(), .SelUncachedAdr, .SelBusWord(),
.CacheBusAck(ICacheBusAck),
.FetchBuffer, .PAdr(PCPF),
.RW, .CPUBusy,
.BusRW, .CPUBusy,
.BusStall, .BusCommitted());
mux2 #(32) UnCachedDataMux(.d0(FinalInstrRawF), .d1(FetchBuffer[32-1:0]),
@ -239,13 +238,13 @@ module ifu (
end else begin : passthrough
assign IFUHADDR = PCPF;
logic CaptureEn;
logic [1:0] RW;
assign RW = RWF & ~{ITLBMissF, ITLBMissF};
logic [1:0] BusRW;
assign BusRW = IFURWF & ~{ITLBMissF, ITLBMissF};
assign IFUHSIZE = 3'b010;
ahbinterface #(0) ahbinterface(.HCLK(clk), .HRESETn(~reset), .HREADY(IFUHREADY),
.HRDATA(HRDATA), .HTRANS(IFUHTRANS), .HWRITE(IFUHWRITE), .HWDATA(),
.HWSTRB(), .RW, .ByteMask(), .WriteData('0),
.HWSTRB(), .BusRW, .ByteMask(), .WriteData('0),
.CPUBusy, .BusStall, .BusCommitted(), .ReadDataWord(InstrRawF[31:0]));
assign IFUHBURST = 3'b0;

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@ -229,10 +229,9 @@ module lsu (
logic SelBusWord;
logic [`XLEN-1:0] PreHWDATA; //*** change name
logic [`XLEN/8-1:0] ByteMaskMDelay;
logic [1:0] CacheRW, UnCacheRW;
logic [1:0] CacheBusRW, BusRW;
assign CacheRW = {DCacheFetchLine, DCacheWriteLine} & ~{IgnoreRequest, IgnoreRequest};
assign UnCacheRW = LSURWM & ~{IgnoreRequest, IgnoreRequest} & ~{CacheableM, CacheableM};
assign BusRW = LSURWM & ~{IgnoreRequest, IgnoreRequest} & ~{CacheableM, CacheableM};
cache #(.LINELEN(`DCACHE_LINELENINBITS), .NUMLINES(`DCACHE_WAYSIZEINBYTES*8/LINELEN),
.NUMWAYS(`DCACHE_NUMWAYS), .LOGBWPL(LOGBWPL), .WORDLEN(`LLEN), .MUXINTERVAL(`XLEN), .DCACHE(1)) dcache(
@ -243,16 +242,16 @@ module lsu (
.CacheStall(DCacheStallM), .CacheMiss(DCacheMiss), .CacheAccess(DCacheAccess),
.IgnoreRequestTLB, .TrapM, .CacheCommitted(DCacheCommittedM),
.CacheBusAdr(DCacheBusAdr), .ReadDataWord(ReadDataWordM),
.FetchBuffer, .CacheFetchLine(DCacheFetchLine),
.CacheWriteLine(DCacheWriteLine), .CacheBusAck(DCacheBusAck), .InvalidateCache(1'b0));
.FetchBuffer, .CacheBusRW,
.CacheBusAck(DCacheBusAck), .InvalidateCache(1'b0));
ahbcacheinterface #(WORDSPERLINE, LINELEN, LOGBWPL, `DCACHE) ahbcacheinterface(
.HCLK(clk), .HRESETn(~reset),
.HRDATA,
.HSIZE(LSUHSIZE), .HBURST(LSUHBURST), .HTRANS(LSUHTRANS), .HWRITE(LSUHWRITE), .HREADY(LSUHREADY),
.WordCount, .SelBusWord,
.Funct3(LSUFunct3M), .HADDR(LSUHADDR), .CacheBusAdr(DCacheBusAdr), .CacheRW,
.Funct3(LSUFunct3M), .HADDR(LSUHADDR), .CacheBusAdr(DCacheBusAdr), .CacheBusRW,
.CacheBusAck(DCacheBusAck), .FetchBuffer, .PAdr(PAdrM),
.SelUncachedAdr, .RW(UnCacheRW), .CPUBusy,
.SelUncachedAdr, .BusRW, .CPUBusy,
.BusStall, .BusCommitted(BusCommittedM));
mux2 #(`LLEN) UnCachedDataMux(.d0(ReadDataWordM), .d1({{`LLEN-`XLEN{1'b0}}, FetchBuffer[`XLEN-1:0] }),
@ -271,15 +270,15 @@ module lsu (
end else begin : passthrough // just needs a register to hold the value from the bus
logic CaptureEn;
logic [1:0] RW;
assign RW = LSURWM & ~{IgnoreRequest, IgnoreRequest};
logic [1:0] BusRW;
assign BusRW = LSURWM & ~{IgnoreRequest, IgnoreRequest};
assign LSUHADDR = PAdrM;
assign LSUHSIZE = LSUFunct3M;
ahbinterface #(1) ahbinterface(.HCLK(clk), .HRESETn(~reset), .HREADY(LSUHREADY),
.HRDATA(HRDATA), .HTRANS(LSUHTRANS), .HWRITE(LSUHWRITE), .HWDATA(LSUHWDATA),
.HWSTRB(LSUHWSTRB), .RW, .ByteMask(ByteMaskM), .WriteData(LSUWriteDataM),
.HWSTRB(LSUHWSTRB), .BusRW, .ByteMask(ByteMaskM), .WriteData(LSUWriteDataM),
.CPUBusy, .BusStall, .BusCommitted(BusCommittedM), .ReadDataWord(ReadDataWordM));
assign ReadDataWordMuxM = ReadDataWordM; // from byte swapping