Added lock signal to ensure AHB speaks with the right bus

This commit is contained in:
slmnemo 2022-06-08 02:19:21 +00:00
parent 6d36150c3d
commit 2d76953d42
6 changed files with 36 additions and 22 deletions

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@ -45,6 +45,7 @@ module ahblite (
input logic IFUBusRead,
output logic [`XLEN-1:0] IFUBusHRDATA,
output logic IFUBusAck,
output logic IFUBusLock,
input logic [2:0] IFUBurstType,
input logic [1:0] IFUTransType,
input logic IFUBurstDone,
@ -59,6 +60,7 @@ module ahblite (
input logic [1:0] LSUTransType,
input logic LSUBurstDone,
output logic LSUBusAck,
output logic LSUBusLock,
// AHB-Lite external signals
(* mark_debug = "true" *) input logic [`AHBW-1:0] HRDATA,
(* mark_debug = "true" *) input logic HREADY, HRESP,
@ -116,21 +118,21 @@ module ahblite (
else NextBusState = IDLE;
MEMREAD: if (HREADY) NextBusState = MEMREADNEXT;
else NextBusState = MEMREAD;
MEMREADNEXT: if (LSUBurstDone & ~IFUBusRead) NextBusState = IDLE;
else if (LSUBurstDone & IFUBusRead) NextBusState = INSTRREAD;
MEMREADNEXT: if (LSUBurstDone & ~(IFUBusRead & ~HREADY)) NextBusState = IDLE;
else if (LSUBurstDone & IFUBusRead & HREADY) NextBusState = INSTRREAD;
else if (HREADY) NextBusState = MEMREADNEXT;
else NextBusState = MEMREAD;
MEMWRITE: if (HREADY) NextBusState = MEMWRITENEXT;
else NextBusState = MEMWRITE;
MEMWRITENEXT: if (LSUBurstDone & ~IFUBusRead) NextBusState = IDLE;
else if (LSUBurstDone & IFUBusRead) NextBusState = INSTRREAD;
MEMWRITENEXT: if (LSUBurstDone & ~(IFUBusRead & ~HREADY)) NextBusState = IDLE;
else if (LSUBurstDone & IFUBusRead & HREADY) NextBusState = INSTRREAD;
else if (HREADY) NextBusState = MEMWRITENEXT;
else NextBusState = MEMWRITE;
INSTRREAD: if (HREADY) NextBusState = INSTRREADNEXT;
else NextBusState = INSTRREAD;
INSTRREADNEXT: if (IFUBurstDone & ~LSUBusRead & ~LSUBusWrite) NextBusState = IDLE;
else if (IFUBurstDone & LSUBusRead) NextBusState = MEMREAD;
else if (IFUBurstDone & LSUBusWrite) NextBusState = MEMWRITE;
else if (IFUBurstDone & LSUBusRead & HREADY) NextBusState = MEMREAD;
else if (IFUBurstDone & LSUBusWrite & HREADY) NextBusState = MEMWRITE;
else if (HREADY) NextBusState = INSTRREADNEXT;
else NextBusState = INSTRREAD;
default: NextBusState = IDLE;
@ -161,7 +163,7 @@ module ahblite (
assign HPROT = 4'b0011; // not used; see Section 3.7
assign HTRANS = SubsequentAccess ? 2'b11 : (NextBusState != IDLE) ? 2'b10 : 2'b00; // SEQ if not first read or write, NONSEQ if first read or write, IDLE otherwise
assign HTRANS = (GrantData) ? LSUTransType : IFUTransType; // SEQ if not first read or write, NONSEQ if first read or write, IDLE otherwise
assign HMASTLOCK = 0; // no locking supported
assign HWRITE = (NextBusState == MEMWRITE) | (NextBusState == MEMWRITENEXT);
// delay write data by one cycle for
@ -177,6 +179,8 @@ module ahblite (
assign IFUBusHRDATA = HRDATA;
assign LSUBusHRDATA = HRDATA;
assign IFUBusLock = (NextBusState == INSTRREAD) | (NextBusState == INSTRREADNEXT);
assign LSUBusLock = (NextBusState == MEMWRITENEXT) | (NextBusState == MEMREADNEXT) | (NextBusState == MEMREAD) | (NextBusState == MEMWRITE);
assign IFUBusAck = (BusState == INSTRREADNEXT);
assign LSUBusAck = (BusState == MEMREADNEXT) | (BusState == MEMWRITENEXT);

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@ -38,6 +38,7 @@ module ifu (
// Bus interface
(* mark_debug = "true" *) input logic [`XLEN-1:0] IFUBusHRDATA,
(* mark_debug = "true" *) input logic IFUBusAck,
(* mark_debug = "true" *) input logic IFUBusLock,
(* mark_debug = "true" *) output logic [`PA_BITS-1:0] IFUBusAdr,
(* mark_debug = "true" *) output logic IFUBusRead,
(* mark_debug = "true" *) output logic IFUStallF,
@ -192,7 +193,7 @@ module ifu (
busdp #(WORDSPERLINE, LINELEN, LOGWPL, CACHE_ENABLED)
busdp(.clk, .reset,
.LSUBusHRDATA(IFUBusHRDATA), .LSUBusAck(IFUBusAck), .LSUBusWrite(), .LSUBusWriteCrit(),
.LSUBusHRDATA(IFUBusHRDATA), .LSUBusAck(IFUBusAck), .LSUBusLock(IFUBusLock), .LSUBusWrite(), .LSUBusWriteCrit(),
.LSUBusRead(IFUBusRead), .LSUBusSize(), .LSUBurstType(IFUBurstType), .LSUTransType(IFUTransType), .LSUBurstDone(IFUBurstDone),
.LSUFunct3M(3'b010), .LSUBusAdr(IFUBusAdr), .DCacheBusAdr(ICacheBusAdr),
.WordCount(),

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@ -40,6 +40,7 @@ module busdp #(parameter WORDSPERLINE, LINELEN, LOGWPL, CACHE_ENABLED)
// bus interface
input logic [`XLEN-1:0] LSUBusHRDATA,
input logic LSUBusAck,
input logic LSUBusLock,
output logic LSUBusWrite,
output logic LSUBusRead,
output logic [2:0] LSUBusSize,
@ -88,6 +89,6 @@ module busdp #(parameter WORDSPERLINE, LINELEN, LOGWPL, CACHE_ENABLED)
busfsm #(WordCountThreshold, LOGWPL, CACHE_ENABLED) busfsm(
.clk, .reset, .IgnoreRequest, .LSURWM, .DCacheFetchLine, .DCacheWriteLine,
.LSUBusAck, .CPUBusy, .CacheableM, .BusStall, .LSUBusWrite, .LSUBusWriteCrit, .LSUBusRead,
.LSUBusAck, .LSUBusLock, .CPUBusy, .CacheableM, .BusStall, .LSUBusWrite, .LSUBusWriteCrit, .LSUBusRead,
.LSUBurstType, .LSUTransType, .LSUBurstDone, .DCacheBusAck, .BusCommittedM, .SelUncachedAdr, .WordCount, .WordCountDelayed);
endmodule

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@ -41,6 +41,7 @@ module busfsm #(parameter integer WordCountThreshold,
input logic DCacheFetchLine,
input logic DCacheWriteLine,
input logic LSUBusAck,
input logic LSUBusLock,
input logic CPUBusy,
input logic CacheableM,
@ -97,7 +98,7 @@ module busfsm #(parameter integer WordCountThreshold,
assign NextWordCount = WordCount + 1'b1;
assign WordCountFlag = (WordCountDelayed == WordCountThreshold[LOGWPL-1:0]);
assign CntEn = PreCntEn & LSUBusAck | (DCacheFetchLine | DCacheWriteLine);
assign CntEn = PreCntEn & LSUBusAck | ((DCacheFetchLine | DCacheWriteLine) & LSUBusLock);
assign UnCachedAccess = ~CACHE_ENABLED | ~CacheableM;
@ -133,16 +134,16 @@ module busfsm #(parameter integer WordCountThreshold,
always_comb begin
case(WordCountThreshold)
4: LocalBurstType = 3'b010; // WRAP4
8: LocalBurstType = 3'b100; // WRAP8
16: LocalBurstType = 3'b110; // WRAP16
3: LocalBurstType = 3'b011; // INCR4
7: LocalBurstType = 3'b101; // INCR8
15: LocalBurstType = 3'b111; // INCR16
default: LocalBurstType = 3'b000; // No Burst
endcase // *** This isn't working, ask someone for help.
endcase
end
assign LSUBurstType = (UnCachedAccess) ? 3'b0 : LocalBurstType ; // Don't want to use burst when doing an Uncached Access
assign LSUBurstDone = (UnCachedAccess) ? LSUBusAck : WordCountFlag & LSUBusAck;
assign LSUTransType = (|WordCount) ? 2'b11 : (LSUBusRead | LSUBusWrite) ? 2'b10 : 2'b00;
assign LSUTransType = (|WordCount | |WordCountDelayed) ? 2'b11 : (LSUBusRead | LSUBusWrite) ? 2'b10 : 2'b00;
assign CntReset = BusCurrState == STATE_BUS_READY & ~(DCacheFetchLine | DCacheWriteLine);
assign BusStall = (BusCurrState == STATE_BUS_READY & ~IgnoreRequest & ((UnCachedAccess & (|LSURWM)) | DCacheFetchLine | DCacheWriteLine)) |

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@ -66,6 +66,7 @@ module lsu (
(* mark_debug = "true" *) output logic LSUBusRead,
(* mark_debug = "true" *) output logic LSUBusWrite,
(* mark_debug = "true" *) input logic LSUBusAck,
(* mark_debug = "true" *) input logic LSUBusLock,
(* mark_debug = "true" *) input logic [`XLEN-1:0] LSUBusHRDATA,
(* mark_debug = "true" *) output logic [`XLEN-1:0] LSUBusHWDATA,
(* mark_debug = "true" *) output logic [2:0] LSUBusSize,
@ -214,7 +215,7 @@ module lsu (
busdp #(WORDSPERLINE, LINELEN, LOGWPL, CACHE_ENABLED) busdp(
.clk, .reset,
.LSUBusHRDATA, .LSUBusAck, .LSUBusWrite, .LSUBusRead, .LSUBusSize, .LSUBurstType, .LSUTransType, .LSUBurstDone,
.LSUBusHRDATA, .LSUBusAck, .LSUBusLock, .LSUBusWrite, .LSUBusRead, .LSUBusSize, .LSUBurstType, .LSUTransType, .LSUBurstDone,
.WordCount, .LSUBusWriteCrit,
.LSUFunct3M, .LSUBusAdr, .DCacheBusAdr, .DCacheFetchLine,
.DCacheWriteLine, .DCacheBusAck, .DCacheBusWriteData, .LSUPAdrM,

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@ -135,7 +135,7 @@ module wallypipelinedcore (
logic [`PA_BITS-1:0] IFUBusAdr;
logic [`XLEN-1:0] IFUBusHRDATA;
logic IFUBusRead;
logic IFUBusAck;
logic IFUBusAck, IFUBusLock;
logic [2:0] IFUBurstType;
logic [1:0] IFUTransType;
logic IFUBurstDone;
@ -144,7 +144,7 @@ module wallypipelinedcore (
logic [`PA_BITS-1:0] LSUBusAdr;
logic LSUBusRead;
logic LSUBusWrite;
logic LSUBusAck;
logic LSUBusAck, LSUBusLock;
logic [`XLEN-1:0] LSUBusHRDATA;
logic [`XLEN-1:0] LSUBusHWDATA;
@ -173,7 +173,7 @@ module wallypipelinedcore (
.StallF, .StallD, .StallE, .StallM,
.FlushF, .FlushD, .FlushE, .FlushM,
// Fetch
.IFUBusHRDATA, .IFUBusAck, .PCF, .IFUBusAdr,
.IFUBusHRDATA, .IFUBusAck, .IFUBusLock, .PCF, .IFUBusAdr,
.IFUBusRead, .IFUStallF, .IFUBurstType, .IFUTransType, .IFUBurstDone,
.ICacheAccess, .ICacheMiss,
@ -254,7 +254,7 @@ module wallypipelinedcore (
.IEUAdrE, .IEUAdrM, .WriteDataE,
.ReadDataM, .FlushDCacheM,
// connected to ahb (all stay the same)
.LSUBusAdr, .LSUBusRead, .LSUBusWrite, .LSUBusAck,
.LSUBusAdr, .LSUBusRead, .LSUBusWrite, .LSUBusAck, .LSUBusLock,
.LSUBusHRDATA, .LSUBusHWDATA, .LSUBusSize, .LSUBurstType, .LSUTransType, .LSUBurstDone,
// connect to csr or privilege and stay the same.
@ -286,8 +286,13 @@ module wallypipelinedcore (
ahblite ebu(// IFU connections
.clk, .reset,
.UnsignedLoadM(1'b0), .AtomicMaskedM(2'b00),
.IFUBusAdr,
.IFUBusRead, .IFUBusHRDATA, .IFUBusAck, .IFUBurstType, .IFUTransType, .IFUBurstDone,
.IFUBusAdr, .IFUBusRead,
.IFUBusHRDATA,
.IFUBurstType,
.IFUTransType,
.IFUBurstDone,
.IFUBusAck,
.IFUBusLock,
// Signals from Data Cache
.LSUBusAdr, .LSUBusRead, .LSUBusWrite, .LSUBusHWDATA,
.LSUBusHRDATA,
@ -296,6 +301,7 @@ module wallypipelinedcore (
.LSUTransType,
.LSUBurstDone,
.LSUBusAck,
.LSUBusLock,
.HRDATA, .HREADY, .HRESP, .HCLK, .HRESETn,
.HADDR, .HWDATA, .HWRITE, .HSIZE, .HBURST,