Retimed peripherals for AHB interface

wally-pipelined/src/fpu/build_temp/freg.sv

@@ -340,7 +340,7 @@ module freg3adr (
   generate
   	for (i = 0; i < numRegs; i = i + 1) begin:register
 
-  		floprc #(`XLEN) (.clk(clk), .reset(reset), .clear(clear), .d(regInput[i][`XLEN-1:0]), .q(regOutput[i][`XLEN-1:0])); 
+  		floprc #(`XLEN) reg[i](.clk(clk), .reset(reset), .clear(clear), .d(regInput[i][`XLEN-1:0]), .q(regOutput[i][`XLEN-1:0])); 
 	end
 
   endgenerate

wally-pipelined/src/fpu/dev/fcsr.sv

@@ -21,7 +21,7 @@ module fcsr(
   //for clk-based write
   assign regInput = (write) ? {24'h0,frm,flags} : regInput;
 
-  floprc #(32) (.clk(clk), .reset(reset), .clear(clear), .d(regInput), .q(regOutput));
+  floprc #(32) fcsrreg(.clk(clk), .reset(reset), .clear(clear), .d(regInput), .q(regOutput));
 
   assign readData = regOutput;
 

wally-pipelined/src/fpu/dev/freg.sv

@@ -28,7 +28,7 @@ module freg1adr (
   generate
   	for (i = 0; i < numRegs; i = i + 1) begin:register
 
-  		floprc #(`XLEN) (.clk(clk), .reset(reset), .clear(clear), .d(regInput[i][`XLEN-1:0]), .q(regOutput[i][`XLEN-1:0])); 
+  		floprc #(`XLEN) freg[i](.clk(clk), .reset(reset), .clear(clear), .d(regInput[i][`XLEN-1:0]), .q(regOutput[i][`XLEN-1:0])); 
 	end
 
   endgenerate
@@ -167,7 +167,7 @@ module freg2adr (
   generate
   	for (i = 0; i < numRegs; i = i + 1) begin:register
 
-  		floprc #(`XLEN) (.clk(clk), .reset(reset), .clear(clear), .d(regInput[i][`XLEN-1:0]), .q(regOutput[i][`XLEN-1:0])); 
+  		floprc #(`XLEN) freg[i](.clk(clk), .reset(reset), .clear(clear), .d(regInput[i][`XLEN-1:0]), .q(regOutput[i][`XLEN-1:0])); 
 	end
 
   endgenerate
@@ -340,7 +340,7 @@ module freg3adr (
   generate
   	for (i = 0; i < numRegs; i = i + 1) begin:register
 
-  		floprc #(`XLEN) (.clk(clk), .reset(reset), .clear(clear), .d(regInput[i][`XLEN-1:0]), .q(regOutput[i][`XLEN-1:0])); 
+  		floprc #(`XLEN) freg[i](.clk(clk), .reset(reset), .clear(clear), .d(regInput[i][`XLEN-1:0]), .q(regOutput[i][`XLEN-1:0])); 
 	end
 
   endgenerate

wally-pipelined/src/uncore/clint.sv

@@ -44,7 +44,9 @@ module clint (
   assign memread  = MemRWclint[1];
   assign memwrite = MemRWclint[0];
   assign HRESPCLINT = 0; // OK
-  assign HREADYCLINT = 1; // Respond immediately
+//  assign HREADYCLINT = 1; // Respond immediately
+  always_ff @(posedge HCLK) // delay response
+    HREADYCLINT <= memread | memwrite;
   
   // word aligned reads
   generate
@@ -63,7 +65,7 @@ module clint (
   // register access
   generate
     if (`XLEN==64) begin
-      always_comb begin
+      always @(posedge HCLK) begin
         case(entry)
           16'h0000: HREADCLINT = {63'b0, MSIP};
           16'h4000: HREADCLINT = MTIMECMP;
@@ -85,7 +87,7 @@ module clint (
           else MTIME <= MTIME + 1;
         end
     end else begin // 32-bit
-      always_comb begin
+      always @(posedge HCLK) begin
         case(entry)
           16'h0000: HREADCLINT = {31'b0, MSIP};
           16'h4000: HREADCLINT = MTIMECMP[31:0];

wally-pipelined/src/uncore/gpio.sv

@@ -45,7 +45,9 @@ module gpio (
   assign memread  = MemRWgpio[1];
   assign memwrite = MemRWgpio[0];
   assign HRESPGPIO = 0; // OK
-  assign HREADYGPIO = 1; // Respond immediately
+  always_ff @(posedge HCLK) // delay response to data cycle
+    HREADYGPIO <= memread | memwrite;
+//  assign HREADYGPIO = 1; // Respond immediately
   
   // word aligned reads
   generate
@@ -67,12 +69,12 @@ module gpio (
   // register access
   generate
     if (`XLEN==64) begin
-      always_comb begin
+      always_ff @(posedge HCLK) begin
         case(entry)
-          8'h00: HREADGPIO = {INPUT_EN, INPUT_VAL};
+          8'h00: HREADGPIO <= {INPUT_EN, INPUT_VAL};
-          8'h08: HREADGPIO = {OUTPUT_VAL, OUTPUT_EN};
+          8'h08: HREADGPIO <= {OUTPUT_VAL, OUTPUT_EN};
-          8'h40: HREADGPIO = 0; // OUT_XOR reads as 0
+          8'h40: HREADGPIO <= 0; // OUT_XOR reads as 0
-          default:  HREADGPIO = 0;
+          default:  HREADGPIO <= 0;
         endcase
       end 
       always_ff @(posedge HCLK or negedge HRESETn) 
@@ -86,14 +88,14 @@ module gpio (
           if (entry == 8'h40) OUTPUT_VAL <= OUTPUT_VAL ^ HWDATA[31:0]; // OUT_XOR
         end
     end else begin // 32-bit
-      always_comb begin
+      always_ff @(posedge HCLK) begin
         case(entry)
-          8'h00: HREADGPIO = INPUT_VAL;
+          8'h00: HREADGPIO <= INPUT_VAL;
-          8'h04: HREADGPIO = INPUT_EN;
+          8'h04: HREADGPIO <= INPUT_EN;
-          8'h08: HREADGPIO = OUTPUT_EN;
+          8'h08: HREADGPIO <= OUTPUT_EN;
-          8'h0C: HREADGPIO = OUTPUT_VAL;
+          8'h0C: HREADGPIO <= OUTPUT_VAL;
-          8'h40: HREADGPIO = 0; // OUT_XOR reads as 0
+          8'h40: HREADGPIO <= 0; // OUT_XOR reads as 0
-          default:  HREADGPIO = 0;
+          default:  HREADGPIO <= 0;
         endcase
       end 
       always_ff @(posedge HCLK or negedge HRESETn) 

wally-pipelined/src/uncore/uart.sv

@@ -48,11 +48,13 @@ module uart (
   assign MEMWb = ~MemRWuart[0];
   assign A = HADDR[2:0];
   assign HRESPUART = 0; // OK
-  assign HREADYUART = 1; // Respond immediately
+  //assign HREADYUART = 1; // Respond immediately
+  always_ff @(posedge HCLK) // delay response to data cycle
+    HREADYUART <= ~MEMRb | ~MEMWb;
 
   generate
     if (`XLEN == 64) begin
-      always_comb begin
+      always @(posedge HCLK) begin
         HREADUART = {Dout, Dout, Dout, Dout, Dout, Dout, Dout, Dout};
         case (HADDR)
           3'b000: Din = HWDATA[7:0];
@@ -66,7 +68,7 @@ module uart (
         endcase 
       end 
     end else begin // 32-bit
-      always_comb begin
+      always @(posedge HCLK) begin
         HREADUART = {Dout, Dout, Dout, Dout};
         case (HADDR[1:0])
           2'b00: Din = HWDATA[7:0];