Partial cleanup of unused signals in caches and bpred.

wally-pipelined/src/cache/cacheway.sv

@@ -54,7 +54,8 @@ module cacheway #(parameter NUMLINES=512, parameter BLOCKLEN = 256, TAGLEN = 26,
    output logic [TAGLEN-1:0] 	      VictimTagWay
    );
 
-  logic [NUMLINES-1:0] 		      ValidBits, DirtyBits;
+  logic [NUMLINES-1:0] 		      ValidBits;
+  logic [NUMLINES-1:0] 		      DirtyBits;
   logic [BLOCKLEN-1:0] 		      ReadDataBlockWay;
   logic [TAGLEN-1:0] 		      ReadTag;
   logic 			      Valid;
@@ -117,21 +118,18 @@ module cacheway #(parameter NUMLINES=512, parameter BLOCKLEN = 256, TAGLEN = 26,
 
   generate
     if(DIRTY_BITS) begin
+
       always_ff @(posedge clk, posedge reset) begin
 	if (reset) 
   	  DirtyBits <= {NUMLINES{1'b0}};
 	else if (SetDirty & (WriteEnable | VDWriteEnable)) DirtyBits[WAdr] <= 1'b1;
 	else if (ClearDirty & (WriteEnable | VDWriteEnable)) DirtyBits[WAdr] <= 1'b0;
       end
-    end
-  endgenerate
 
-  // Since this is always updated on a clock edge we cannot include reset.
-  generate
-    if(DIRTY_BITS) begin
       always_ff @(posedge clk) begin
 	Dirty <= DirtyBits[RAdr];
       end
+
     end else begin
       assign Dirty = 1'b0;
     end

wally-pipelined/src/cache/dcache.sv

@@ -70,14 +70,9 @@ module dcache
    output logic [2:0] 	       DCtoAHBSizeM
    );
 
-/*  localparam integer	       BLOCKLEN = 256;
-  localparam integer	       NUMLINES = 64;
-  localparam integer	       NUMWAYS = 4;
-  localparam integer	       NUMREPL_BITS = 3;*/
   localparam integer	       BLOCKLEN = `DCACHE_BLOCKLENINBITS;
   localparam integer	       NUMLINES = `DCACHE_WAYSIZEINBYTES*8/BLOCKLEN;
   localparam integer	       NUMWAYS = `DCACHE_NUMWAYS;
-  localparam integer	       NUMREPL_BITS = `DCACHE_REPLBITS; // *** not used
 
   localparam integer	       BLOCKBYTELEN = BLOCKLEN/8;
   localparam integer	       OFFSETLEN = $clog2(BLOCKBYTELEN);
@@ -170,7 +165,7 @@ module dcache
 		      .reset,
 		      .RAdr,
 		      .WAdr,
-		      .PAdr(MemPAdrM[`PA_BITS-1:0]),
+		      .PAdr(MemPAdrM),
 		      .WriteEnable(SRAMWayWriteEnable),
 		      .VDWriteEnable,		      
 		      .WriteWordEnable(SRAMWordEnable),

wally-pipelined/src/cache/icache.sv

@@ -65,16 +65,12 @@ module icache
   localparam LOGWPL = $clog2(WORDSPERLINE);
 
   localparam FetchCountThreshold = WORDSPERLINE - 1;
-  localparam BlockByteLength = BLOCKLEN / 8;
-
-  localparam OFFSETWIDTH = $clog2(BlockByteLength);
 
   localparam integer 	       PA_WIDTH = `PA_BITS - 2;
   localparam integer 	       NUMWAYS = `ICACHE_NUMWAYS;
   
 
   // Input signals to cache memory
-  logic 		    FlushMem;
   logic 		    ICacheMemWriteEnable;
   logic [BLOCKLEN-1:0] 	    ICacheMemWriteData;
   logic [`PA_BITS-1:0] 	    PCTagF;  
@@ -91,7 +87,7 @@ module icache
   logic 			 FetchCountFlag;
   logic 			 CntEn;
   
-  logic [1:0] 			 SelAdr_q;
+  logic [1:1] 			 SelAdr_q;
   
   
   logic [LOGWPL-1:0] 	       FetchCount, NextFetchCount;
@@ -252,11 +248,11 @@ module icache
 
   // this mux needs to be delayed 1 cycle as it occurs 1 pipeline stage later.
   // *** read enable may not be necessary.
-  flopenr #(2) SelAdrReg(.clk(clk),
+  flopenr #(1) SelAdrReg(.clk(clk),
 			.reset(reset),
 			.en(ICacheReadEn),
-			.d(SelAdr),
-			.q(SelAdr_q));
+			.d(SelAdr[1]),
+			.q(SelAdr_q[1]));
   
   assign PCTagF = SelAdr_q[1] ? PCPSpillF : PCPF;
 
@@ -281,29 +277,25 @@ module icache
 
   assign SRAMWayWriteEnable = ICacheMemWriteEnable ? VictimWay : '0;
 
-  icachefsm #(.BLOCKLEN(BLOCKLEN)) 
-  controller(.clk,
-	     .reset,
-	     .StallF,
-	     .ICacheReadEn,
-	     .ICacheMemWriteEnable,
-	     .ICacheStallF,
-	     .ITLBMissF,
-	     .ITLBWriteF,
-	     .WalkerInstrPageFaultF,
-	     .InstrAckF,
-	     .InstrReadF,
-	     .hit,
-	     .FetchCountFlag,
-	     .spill,
-	     .spillSave,
-	     .CntEn,
-	     .CntReset,
-	     .SelAdr,
-	     .LRUWriteEn
-	     );
+  icachefsm  controller(.clk,
+			.reset,
+			.StallF,
+			.ICacheReadEn,
+			.ICacheMemWriteEnable,
+			.ICacheStallF,
+			.ITLBMissF,
+			.ITLBWriteF,
+			.WalkerInstrPageFaultF,
+			.InstrAckF,
+			.InstrReadF,
+			.hit,
+			.FetchCountFlag,
+			.spill,
+			.spillSave,
+			.CntEn,
+			.CntReset,
+			.SelAdr,
+			.LRUWriteEn);
 
-  // For now, assume no writes to executable memory
-  assign FlushMem = 1'b0;
 endmodule
 

wally-pipelined/src/cache/icachefsm.sv

@@ -25,9 +25,8 @@
 
 `include "wally-config.vh"
 
-module icachefsm #(parameter BLOCKLEN = 256) 
-  (
-   // Inputs from pipeline
+module icachefsm
+  (// Inputs from pipeline
    input logic 	      clk, reset,
 
    input logic 	      StallF,
@@ -115,8 +114,6 @@ module icachefsm #(parameter BLOCKLEN = 256)
   
   statetype CurrState, NextState;
   logic 		       PreCntEn;
-  logic 		       UnalignedSelect;
-  logic            SavePC; // unused right now *** consider deleting
 
   // the FSM is always runing, do not stall.
   always_ff @(posedge clk, posedge reset)
@@ -125,7 +122,6 @@ module icachefsm #(parameter BLOCKLEN = 256)
 
   // Next state logic
   always_comb begin
-    UnalignedSelect = 1'b0;
     CntReset = 1'b0;
     PreCntEn = 1'b0;
     //InstrReadF = 1'b0;
@@ -133,7 +129,6 @@ module icachefsm #(parameter BLOCKLEN = 256)
     spillSave = 1'b0;
     SelAdr = 2'b00;
     ICacheReadEn = 1'b0;
-    SavePC = 1'b0;
     ICacheStallF = 1'b1;
     LRUWriteEn = 1'b0;
     case (CurrState)
@@ -143,7 +138,6 @@ module icachefsm #(parameter BLOCKLEN = 256)
         if (ITLBMissF) begin
           NextState = STATE_TLB_MISS;
         end else if (hit & ~spill) begin
-          SavePC = 1'b1;
           ICacheStallF = 1'b0;
 	  LRUWriteEn = 1'b1;
 	  if(StallF) begin
@@ -176,7 +170,6 @@ module icachefsm #(parameter BLOCKLEN = 256)
       // branch 1,  hit spill and 2, miss spill hit
       STATE_HIT_SPILL: begin
         SelAdr = 2'b10;
-        UnalignedSelect = 1'b1;
         ICacheReadEn = 1'b1;
         if (hit) begin
           NextState = STATE_HIT_SPILL_FINAL;
@@ -202,15 +195,12 @@ module icachefsm #(parameter BLOCKLEN = 256)
       end
       STATE_HIT_SPILL_MERGE: begin
         SelAdr = 2'b10;
-        UnalignedSelect = 1'b1;
         ICacheReadEn = 1'b1;
         NextState = STATE_HIT_SPILL_FINAL;
       end
       STATE_HIT_SPILL_FINAL: begin
         ICacheReadEn = 1'b1;
         SelAdr = 2'b00;
-        UnalignedSelect = 1'b1;
-        SavePC = 1'b1;
         ICacheStallF = 1'b0;
 	LRUWriteEn = 1'b1;
 	
@@ -280,7 +270,6 @@ module icachefsm #(parameter BLOCKLEN = 256)
       end
       STATE_MISS_SPILL_2: begin
         SelAdr = 2'b10;
-        UnalignedSelect = 1'b1;
         spillSave = 1'b1; /// *** Could pipeline these to make it clearer in the fsm.
         ICacheReadEn = 1'b1;
         NextState = STATE_MISS_SPILL_2_START;
@@ -292,8 +281,6 @@ module icachefsm #(parameter BLOCKLEN = 256)
         end else begin
           ICacheReadEn = 1'b1;
           SelAdr = 2'b00;
-          UnalignedSelect = 1'b1;
-          SavePC = 1'b1;
           ICacheStallF = 1'b0;
 	  LRUWriteEn = 1'b1;
 	  if(StallF) begin
@@ -321,15 +308,12 @@ module icachefsm #(parameter BLOCKLEN = 256)
       end
       STATE_MISS_SPILL_MERGE: begin
         SelAdr = 2'b10;
-        UnalignedSelect = 1'b1;
         ICacheReadEn = 1'b1;	
         NextState = STATE_MISS_SPILL_FINAL;
       end
       STATE_MISS_SPILL_FINAL: begin
         ICacheReadEn = 1'b1;
         SelAdr = 2'b00;
-        UnalignedSelect = 1'b1;
-        SavePC = 1'b1;
         ICacheStallF = 1'b0;	
 	LRUWriteEn = 1'b1;
 	if(StallF) begin

wally-pipelined/src/ifu/BTBPredictor.sv

@@ -33,7 +33,7 @@ module BTBPredictor
     )
   (input  logic clk,
    input logic 		    reset,
-   input logic 		    StallF, StallD, StallE, FlushF, FlushD, FlushE,
+   input logic 		    StallF, StallE,
    input logic [`XLEN-1:0]  LookUpPC,
    output logic [`XLEN-1:0] TargetPC,
    output logic [4:0] 	    InstrClass,
@@ -77,17 +77,6 @@ module BTBPredictor
   end
   assign Valid = ValidBits[LookUpPCIndexQ];
 
-/* -----\/----- EXCLUDED -----\/-----
-
-  regfile2p1r1w #(10, 1) validMem(.clk(clk),
-				  .reset(reset),
-				  .RA1(LookUpPCIndexQ),
-				  .RD1(Valid),
-				  .REN1(1'b1),
-				  .WA1(UpdatePCIndexQ),
-				  .WD1(1'b1),
-				  .WEN1(UpdateEN));
- -----/\----- EXCLUDED -----/\----- */
 
   flopenr #(1) UpdateENReg(.clk(clk),
 			  .reset(reset),

wally-pipelined/src/ifu/bpred.sv

@@ -30,8 +30,8 @@
 
 module bpred 
   (input logic clk, reset,
-   input logic 		    StallF, StallD, StallE, StallM, StallW, 
-   input logic 		    FlushF, FlushD, FlushE, FlushM, FlushW,
+   input logic 		    StallF, StallD, StallE, 
+   input logic 		    FlushF, FlushD, FlushE,
    // Fetch stage
    // the prediction
    input logic [`XLEN-1:0]  PCNextF, // *** forgot to include this one on the I/O list
@@ -67,8 +67,6 @@ module bpred
   logic 		    PredictionPCWrongE;
   logic 		    PredictionInstrClassWrongE;
   
-  logic [`XLEN-1:0] 	    CorrectPCE;
-
 
   // Part 1 branch direction prediction
 
@@ -171,10 +169,6 @@ module bpred
 			       .UpdateInvalid(PredictionInstrClassWrongE),
 			       .UpdateInstrClass(InstrClassE));
 
-  // need to forward when updating to the same address as reading.
-  //assign CorrectPCE = PCSrcE ? PCTargetE : PCLinkE;
-  //assign TargetPC = (PCE == PCNextF) ? CorrectPCE : BTBPredPCF;
-
   // Part 3 RAS
   // *** need to add the logic to restore RAS on flushes.  We will use incr for this.
   RASPredictor RASPredictor(.clk(clk),

wally-pipelined/src/ifu/globalHistoryPredictor.sv

@@ -32,7 +32,7 @@ module globalHistoryPredictor
     )
   (input logic clk,
    input logic 		   reset,
-   input logic 		   StallF, StallD, StallE, FlushF, FlushD, FlushE,
+   input logic 		   StallF, StallE,
    input logic [`XLEN-1:0] PCNextF,
    output logic [1:0] 	   BPPredF,
    // update

wally-pipelined/src/ifu/gsharePredictor.sv

@@ -32,7 +32,7 @@ module gsharePredictor
     )
   (input logic clk,
    input logic 		   reset,
-   input logic 		   StallF, StallD, StallE, FlushF, FlushD, FlushE,
+   input logic 		   StallF, StallE,
    input logic [`XLEN-1:0] PCNextF,
    output logic [1:0] 	   BPPredF,
    // update

wally-pipelined/src/ifu/localHistoryPredictor.sv

@@ -33,7 +33,7 @@ module localHistoryPredictor
       )
   (input logic clk,
    input logic 		   reset,
-   input logic 		   StallF, StallD, StallE, FlushF, FlushD, FlushE,
+   input logic 		   StallF,  StallE, FlushF,
    input logic [`XLEN-1:0] LookUpPC,
    output logic [1:0] 	   Prediction,
    // update

wally-pipelined/src/lsu/lsu.sv

@@ -157,7 +157,6 @@ module lsu
 
   // arbiter between IEU and hptw
   lsuArb arbiter(.clk(clk),
-		 .reset(reset),
 		 // HPTW connection
 		 .SelPTW(SelPTW),
 		 .HPTWRead(HPTWRead),
@@ -168,7 +167,7 @@ module lsu
 		 .Funct3M(Funct3M),
 		 .AtomicM(AtomicM),
 		 .MemAdrM(MemAdrM),
-		 .MemAdrE(MemAdrE),		 
+		 .MemAdrE(MemAdrE[11:0]),		 
 		 .CommittedM(CommittedM),
 		 .PendingInterruptM(PendingInterruptM),		
 		 .StallW(StallW),

wally-pipelined/src/lsu/lsuArb.sv

@@ -27,7 +27,7 @@
 `include "wally-config.vh"
 
 module lsuArb 
-  (input  logic clk, reset,
+  (input  logic clk,
 
    // from page table walker
    input logic 		       SelPTW,
@@ -40,7 +40,7 @@ module lsuArb
    input logic [2:0] 	       Funct3M,
    input logic [1:0] 	       AtomicM,
    input logic [`XLEN-1:0]     MemAdrM,
-   input logic [`XLEN-1:0]     MemAdrE,
+   input logic [11:0] 	       MemAdrE,
    input logic 		       StallW,
    input logic 		       PendingInterruptM,
    // to CPU