Found the ahb burst bug.

We had instruction fetches fixed HSIZE = 2 (4 bytes) for all requests.  It should be HSIZE = 3 (8 bytes) for cache fetches and 4 for uncached reads.  The reason this worked for non burst is the DDR4 memory controller returns the full double word even for 4 byte reads.  In burst mode the second beat ending up pointing to the next 4 bytes rather than the next 8 bytes.

pipelined/src/ebu/ahbinterface.sv

@@ -34,7 +34,7 @@
 
 `include "wally-config.vh"
 
-module ahbinterface #(parameter WRITEABLE = 0)
+module ahbinterface #(parameter WRITEABLE = 0) // **** modify to use LSU/ifu parameter to control widths of buses
   (
   input logic                HCLK, HRESETn,
   
@@ -57,6 +57,7 @@ module ahbinterface #(parameter WRITEABLE = 0)
   
   logic                       CaptureEn;
 
+  /// *** only 32 bit for IFU.
   flopen #(`XLEN) fb(.clk(HCLK), .en(CaptureEn), .d(HRDATA), .q(ReadDataWord));
 
   if(WRITEABLE) begin

pipelined/src/ebu/ahbmulticontroller.sv

@@ -41,6 +41,7 @@ module ahbmulticontroller
    input logic                clk, reset,
    // Signals from IFU
    input logic [`PA_BITS-1:0] IFUHADDR, 
+   input logic [2:0]          IFUHSIZE,
    input logic [2:0]          IFUHBURST,
    input logic [1:0]          IFUHTRANS,
    output logic               IFUHREADY, 
@@ -69,28 +70,23 @@ module ahbmulticontroller
    (* mark_debug = "true" *) output logic HMASTLOCK
    );
 
-  localparam                  ADRBITS = $clog2(`XLEN/8); // address bits for Byte Mask generator
-
   typedef enum                logic [1:0] {IDLE, ARBITRATE} statetype;
   statetype CurrState, NextState;
-  logic                       LSUGrant;
-  logic [ADRBITS-1:0]         HADDRD;
-  logic [1:0]                 HSIZED;
 
   logic [1:0]                 save, restore, dis, sel;
   logic                       both;
 
-  logic [`PA_BITS-1:0]        IFUHADDRSave, IFUHADDROut;
-  logic [1:0]                 IFUHTRANSSave, IFUHTRANSOut;
-  logic [2:0]                 IFUHBURSTSave, IFUHBURSTOut;
+  logic [`PA_BITS-1:0]        IFUHADDROut;
+  logic [1:0]                 IFUHTRANSOut;
+  logic [2:0]                 IFUHBURSTOut;
   logic [2:0]                 IFUHSIZEOut;
   logic                       IFUHWRITEOut;
   
-  logic [`PA_BITS-1:0]        LSUHADDRSave, LSUHADDROut;
-  logic [1:0]                 LSUHTRANSSave, LSUHTRANSOut;
-  logic [2:0]                 LSUHBURSTSave, LSUHBURSTOut;
-  logic [2:0]                 LSUHSIZESave, LSUHSIZEOut;
-  logic                       LSUHWRITESave, LSUHWRITEOut;
+  logic [`PA_BITS-1:0]        LSUHADDROut;
+  logic [1:0]                 LSUHTRANSOut;
+  logic [2:0]                 LSUHBURSTOut;
+  logic [2:0]                 LSUHSIZEOut;
+  logic                       LSUHWRITEOut;
 
   logic                       IFUReq, LSUReq;
   logic                       IFUActive, LSUActive;
@@ -112,7 +108,7 @@ module ahbmulticontroller
   // input stage IFU
   controllerinputstage IFUInput(.HCLK, .HRESETn, .Save(save[0]), .Restore(restore[0]), .Disable(dis[0]),
     .Request(IFUReq), .Active(IFUActive),
-    .HWRITEin(1'b0), .HSIZEin(3'b010), .HBURSTin(IFUHBURST), .HTRANSin(IFUHTRANS), .HADDRin(IFUHADDR),
+    .HWRITEin(1'b0), .HSIZEin(IFUHSIZE), .HBURSTin(IFUHBURST), .HTRANSin(IFUHTRANS), .HADDRin(IFUHADDR),
     .HWRITEOut(IFUHWRITEOut), .HSIZEOut(IFUHSIZEOut), .HBURSTOut(IFUHBURSTOut), .HREADYOut(IFUHREADY),
     .HTRANSOut(IFUHTRANSOut), .HADDROut(IFUHADDROut), .HREADYin(HREADY));
 
@@ -125,7 +121,7 @@ module ahbmulticontroller
 
   // output mux //*** rewrite for general number of controllers.
   assign HADDR = sel[1] ? LSUHADDROut : sel[0] ? IFUHADDROut : '0;
-  assign HSIZE = sel[1] ? LSUHSIZEOut : sel[0] ? 3'b010: '0; // Instruction reads are always 32 bits
+  assign HSIZE = sel[1] ? LSUHSIZEOut : sel[0] ? IFUHSIZEOut: '0; 
   assign HBURST = sel[1] ? LSUHBURSTOut : sel[0] ? IFUHBURSTOut : '0; // If doing memory accesses, use LSUburst, else use Instruction burst.
   assign HTRANS = sel[1] ? LSUHTRANSOut : sel[0] ? IFUHTRANSOut: '0; // SEQ if not first read or write, NONSEQ if first read or write, IDLE otherwise
   assign HWRITE = sel[1] ? LSUHWRITEOut : sel[0] ? 1'b0 : '0;

pipelined/src/ifu/ifu.sv

@@ -41,6 +41,7 @@ module ifu (
 (* mark_debug = "true" *)	output logic 				IFUStallF,
 (* mark_debug = "true" *) output logic [2:0]  IFUHBURST,
 (* mark_debug = "true" *) output logic [1:0]  IFUHTRANS,
+(* mark_debug = "true" *) output logic [2:0]  IFUHSIZE,
 (* mark_debug = "true" *) output logic  IFUHWRITE,
 (* mark_debug = "true" *) input logic   IFUHREADY,
 	(* mark_debug = "true" *) output logic [`XLEN-1:0] PCF, 
@@ -234,7 +235,7 @@ module ifu (
       ahbcacheinterface #(WORDSPERLINE, LINELEN, LOGBWPL, `ICACHE) 
       ahbcacheinterface(.HCLK(clk), .HRESETn(~reset),
             .HRDATA,
-            .CacheRW, .HSIZE(), .HBURST(IFUHBURST), .HTRANS(IFUHTRANS),
+            .CacheRW, .HSIZE(IFUHSIZE), .HBURST(IFUHBURST), .HTRANS(IFUHTRANS),
             .Funct3(3'b010), .HADDR(IFUHADDR), .HREADY(IFUHREADY), .HWRITE(IFUHWRITE), .CacheBusAdr(ICacheBusAdr),
             .WordCount(), .SelUncachedAdr, .SelBusWord(),
               .CacheBusAck(ICacheBusAck), 
@@ -249,6 +250,7 @@ module ifu (
       logic CaptureEn;
       logic [1:0] RW;
       assign RW = NonIROMMemRWM & ~{ITLBMissF, ITLBMissF};
+      assign IFUHSIZE = 3'b010;
 
       ahbinterface #(0) ahbinterface(.HCLK(clk), .HRESETn(~reset), .HREADY(IFUHREADY), 
         .HRDATA(HRDATA), .HTRANS(IFUHTRANS), .HWRITE(IFUHWRITE), .HWDATA(),

pipelined/src/lsu/lsu.sv

@@ -216,7 +216,8 @@ module lsu (
     assign MemStage = CPUBusy | MemRWM[0] | reset; // 1 = M stage; 0 = E stage
     assign DTIMAdr = MemStage ? IEUAdrExtM : IEUAdrExtE; // zero extend or contract to PA_BITS
     /* verilator lint_on WIDTH */
-    assign DTIMAccessRW = |MemRWM; 
+    assign DTIMAccessRW = |MemRWM;
+    // *** Ross remove this.
     adrdec dtimdec(IEUAdrExtM, `DTIM_BASE, `DTIM_RANGE, `DTIM_SUPPORTED, DTIMAccessRW, 2'b10, 4'b1111, SelDTIM); // maybe we pull this out of the mmu?
     //assign NonDTIMMemRWM = MemRWM & ~{2{SelDTIM}}; // disable access to bus-based memory map when DTIM is selected
     assign NonDTIMMemRWM = MemRWM; // *** fix

pipelined/src/wally/wallypipelinedcore.sv

@@ -132,18 +132,19 @@ module wallypipelinedcore (
   logic             CommittedM;
 
   // AHB ifu interface
-  logic [`PA_BITS-1:0]         IFUHADDR;
-  logic [2:0]       IFUHBURST;
-  logic [1:0]       IFUHTRANS;
-  logic                     IFUHWRITE;
-  logic                     IFUHREADY;
+  logic [`PA_BITS-1:0] IFUHADDR;
+  logic [2:0]          IFUHBURST;
+  logic [1:0]          IFUHTRANS;
+  logic [2:0]          IFUHSIZE;
+  logic                IFUHWRITE;
+  logic                IFUHREADY;
   
   // AHB LSU interface
-  logic [`PA_BITS-1:0]         LSUHADDR;
-  logic [`XLEN-1:0]         LSUHWDATA;
-  logic [`XLEN/8-1:0]       LSUHWSTRB;
-  logic                     LSUHWRITE;
-  logic                     LSUHREADY;
+  logic [`PA_BITS-1:0] LSUHADDR;
+  logic [`XLEN-1:0]    LSUHWDATA;
+  logic [`XLEN/8-1:0]  LSUHWSTRB;
+  logic                LSUHWRITE;
+  logic                LSUHREADY;
   
   logic             BPPredWrongE;
   logic             BPPredDirWrongM;
@@ -172,7 +173,7 @@ module wallypipelinedcore (
     .FlushF, .FlushD, .FlushE, .FlushM, 
     // Fetch
     .HRDATA, .PCF, .IFUHADDR,
-    .IFUStallF, .IFUHBURST, .IFUHTRANS,
+    .IFUStallF, .IFUHBURST, .IFUHTRANS, .IFUHSIZE,
           .IFUHREADY, .IFUHWRITE,
     .ICacheAccess, .ICacheMiss,
 
@@ -295,6 +296,7 @@ module wallypipelinedcore (
      .IFUHBURST, 
      .IFUHTRANS, 
      .IFUHREADY,
+     .IFUHSIZE,
      // LSU interface
      .LSUHADDR,
      .LSUHWDATA,