This commit is contained in:
bbracker 2021-06-20 00:40:44 -04:00
commit 8462f248aa
4 changed files with 21 additions and 22 deletions

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@ -33,15 +33,15 @@ module ICacheCntrl #(parameter BLOCKLEN = 256) (
// Input the address to read
// The upper bits of the physical pc
input logic [`PA_BITS-1:0] PCNextF,
input logic [`PA_BITS-1:0] PCPF,
input logic [`XLEN-1:0] PCNextF,
input logic [`XLEN-1:0] PCPF,
// Signals to/from cache memory
// The read coming out of it
input logic [31:0] ICacheMemReadData,
input logic ICacheMemReadValid,
// The address at which we want to search the cache memory
output logic [`PA_BITS-1:0] PCTagF,
output logic [`PA_BITS-1:0] PCNextIndexF,
output logic [`XLEN-1:0] PCTagF,
output logic [`XLEN-1:0] PCNextIndexF,
output logic ICacheReadEn,
// Load data into the cache
output logic ICacheMemWriteEnable,
@ -133,8 +133,8 @@ module ICacheCntrl #(parameter BLOCKLEN = 256) (
logic [LOGWPL:0] FetchCount, NextFetchCount;
logic [`PA_BITS-1:0] PCPreFinalF, PCPSpillF;
logic [`PA_BITS-1:OFFSETWIDTH] PCPTrunkF;
logic [`XLEN-1:0] PCPreFinalF, PCPFinalF, PCSpillF;
logic [`XLEN-1:OFFSETWIDTH] PCPTrunkF;
logic [31:0] FinalInstrRawF;
@ -156,11 +156,11 @@ module ICacheCntrl #(parameter BLOCKLEN = 256) (
// on spill we want to get the first 2 bytes of the next cache block.
// the spill only occurs if the PCPF mod BlockByteLength == -2. Therefore we can
// simply add 2 to land on the next cache block.
assign PCPSpillF = PCPF + 2'b10; // *** modelsim does not allow the use of PA_BITS for literal width.
assign PCSpillF = PCPF + `XLEN'b10;
// now we have to select between these three PCs
assign PCPreFinalF = PCMux[0] | StallF ? PCPF : PCNextF; // *** don't like the stallf, but it is necessary
assign PCNextIndexF = PCMux[1] ? PCPSpillF : PCPreFinalF;
assign PCPFinalF = PCMux[1] ? PCSpillF : PCPreFinalF;
// this mux needs to be delayed 1 cycle as it occurs 1 pipeline stage later.
// *** read enable may not be necessary.
@ -170,10 +170,11 @@ module ICacheCntrl #(parameter BLOCKLEN = 256) (
.d(PCMux),
.q(PCMux_q));
assign PCTagF = PCMux_q[1] ? PCPSpillF : PCPF;
assign PCTagF = PCMux_q[1] ? PCSpillF : PCPF;
assign PCNextIndexF = PCPFinalF;
// truncate the offset from PCPF for memory address generation
assign PCPTrunkF = PCTagF[`PA_BITS-1:OFFSETWIDTH];
assign PCPTrunkF = PCTagF[`XLEN-1:OFFSETWIDTH];
// Detect if the instruction is compressed
assign CompressedF = FinalInstrRawF[1:0] != 2'b11;
@ -394,7 +395,7 @@ module ICacheCntrl #(parameter BLOCKLEN = 256) (
// we need to address on that number of bits so the PC is extended to the right by AHBByteLength with zeros.
// fetch count is already aligned to AHBByteLength, but we need to extend back to the full address width with
// more zeros after the addition. This will be the number of offset bits less the AHBByteLength.
logic [`PA_BITS-1:OFFSETWIDTH-LOGWPL] PCPTrunkExtF, InstrPAdrTrunkF ;
logic [`XLEN-1:OFFSETWIDTH-LOGWPL] PCPTrunkExtF, InstrPAdrTrunkF ;
assign PCPTrunkExtF = {PCPTrunkF, {{LOGWPL}{1'b0}}};
// verilator lint_off WIDTH

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@ -8,8 +8,8 @@ module ICacheMem #(parameter NUMLINES=512, parameter BLOCKLEN = 256)
// If flush is high, invalidate the entire cache
input logic flush,
input logic [`PA_BITS-1:0] PCTagF, // physical address
input logic [`PA_BITS-1:0] PCNextIndexF, // virtual address
input logic [`XLEN-1:0] PCTagF, // physical address
input logic [`XLEN-1:0] PCNextIndexF, // virtual address
input logic WriteEnable,
input logic [BLOCKLEN-1:0] WriteLine,
output logic [BLOCKLEN-1:0] ReadLineF,
@ -21,7 +21,7 @@ module ICacheMem #(parameter NUMLINES=512, parameter BLOCKLEN = 256)
localparam OFFSETLEN = $clog2(BLOCKBYTELEN);
localparam INDEXLEN = $clog2(NUMLINES);
// *** BUG. `XLEN needs to be replaced with the virtual address width, S32, S39, or S48
localparam TAGLEN = `PA_BITS - OFFSETLEN - INDEXLEN;
localparam TAGLEN = `XLEN - OFFSETLEN - INDEXLEN;
logic [TAGLEN-1:0] LookupTag;
logic [NUMLINES-1:0] ValidOut;
@ -39,7 +39,7 @@ module ICacheMem #(parameter NUMLINES=512, parameter BLOCKLEN = 256)
cachetags (.*,
.Addr(PCNextIndexF[INDEXLEN+OFFSETLEN-1:OFFSETLEN]),
.ReadData(LookupTag),
.WriteData(PCTagF[`PA_BITS-1:INDEXLEN+OFFSETLEN])
.WriteData(PCTagF[`XLEN-1:INDEXLEN+OFFSETLEN])
);
// Correctly handle the valid bits
@ -55,5 +55,5 @@ module ICacheMem #(parameter NUMLINES=512, parameter BLOCKLEN = 256)
end
DataValidBit <= ValidOut[PCNextIndexF[INDEXLEN+OFFSETLEN-1:OFFSETLEN]];
end
assign HitF = DataValidBit && (LookupTag == PCTagF[`PA_BITS-1:INDEXLEN+OFFSETLEN]);
assign HitF = DataValidBit && (LookupTag == PCTagF[`XLEN-1:INDEXLEN+OFFSETLEN]);
endmodule

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@ -31,8 +31,8 @@ module icache
input logic clk, reset,
input logic StallF, StallD,
input logic FlushD,
input logic [`PA_BITS-1:0] PCNextF,
input logic [`PA_BITS-1:0] PCPF,
input logic [`XLEN-1:0] PCNextF,
input logic [`XLEN-1:0] PCPF,
// Data read in from the ebu unit
input logic [`XLEN-1:0] InstrInF,
input logic InstrAckF,
@ -58,7 +58,7 @@ module icache
logic ICacheMemWriteEnable;
logic [BLOCKLEN-1:0] ICacheMemWriteData;
logic EndFetchState;
logic [`PA_BITS-1:0] PCTagF, PCNextIndexF;
logic [`XLEN-1:0] PCTagF, PCNextIndexF;
// Output signals from cache memory
logic [31:0] ICacheMemReadData;
logic ICacheMemReadValid;

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@ -138,9 +138,7 @@ module ifu (
// jarred 2021-03-14 Add instrution cache block to remove rd2
assign PCNextPF = PCNextF; // Temporary workaround until iTLB is live
icache icache(.*,
.PCNextF(PCNextF[`PA_BITS-1:0]),
.PCPF(PCPFmmu));
icache icache(.*);