Divided stage modules into seperate "Module" and "Stage" modules.

src/Cpu/Alu.bsv

@@ -5,86 +5,78 @@
 // reponsible for mathematical operations inside the CPU.
 //
 import RV_ISA::*;
-export RV_ISA::*, AluCfg, AluIfc(..), mkAlu;
-
-function Maybe#(Bit#(32)) execute32(RVALUOperator operator, Bit#(32) operand1, Bit#(32) operand2);
-    let sum         = operand1 + operand2;
-    let difference  = operand1 - operand2;
-    let bitwise_and = operand1 & operand2;
-    let bitwise_or  = operand1 | operand2;
-    let bitwise_xor = operand1 ^ operand2;
-    let sltu        = (operand1 < operand2 ? 1 : 0);
-    let slt         = (begin
-        Int#(32) signedOperand1 = unpack(pack(operand1));
-        Int#(32) signedOperand2 = unpack(pack(operand2));
-        (signedOperand1 < signedOperand2 ? 1 : 0);
-    end);    
-
-    let sll     = operand1 << operand2[4:0];
-    let sra     = signedShiftRight(operand1, operand2[4:0]);
-    let srl     = operand1 >> operand2[4:0];
-
-    return case(operator)
-        alu_ADD:    tagged Valid sum;
-        alu_SUB:    tagged Valid difference;
-        alu_AND:    tagged Valid bitwise_and;
-        alu_OR:     tagged Valid bitwise_or;
-        alu_XOR:    tagged Valid bitwise_xor;
-        alu_SLTU:   tagged Valid sltu;
-        alu_SLT:    tagged Valid slt;
-        alu_SLL:    tagged Valid sll;
-        alu_SRA:    tagged Valid sra;
-        alu_SRL:    tagged Valid srl;
-        default:    tagged Invalid;
-    endcase;
-endfunction
-
-function Maybe#(Bit#(64)) execute64(RVALUOperator operator, Bit#(64) operand1, Bit#(64) operand2);
-    let sum         = operand1 + operand2;
-    let difference  = operand1 - operand2;
-    let bitwise_and = operand1 & operand2;
-    let bitwise_or  = operand1 | operand2;
-    let bitwise_xor = operand1 ^ operand2;
-    let sltu        = (operand1 < operand2 ? 1 : 0);
-    let slt         = (begin
-        Int#(64) signedOperand1 = unpack(pack(operand1));
-        Int#(64) signedOperand2 = unpack(pack(operand2));
-        (signedOperand1 < signedOperand2 ? 1 : 0);
-    end);    
-
-    let sll     = operand1 << operand2[5:0];
-    let sra     = signedShiftRight(operand1, operand2[5:0]);
-    let srl     = operand1 >> operand2[5:0];
-
-    return case(operator)
-        alu_ADD:    tagged Valid sum;
-        alu_SUB:    tagged Valid difference;
-        alu_AND:    tagged Valid bitwise_and;
-        alu_OR:     tagged Valid bitwise_or;
-        alu_XOR:    tagged Valid bitwise_xor;
-        alu_SLTU:   tagged Valid sltu;
-        alu_SLT:    tagged Valid slt;
-        alu_SLL:    tagged Valid sll;
-        alu_SRA:    tagged Valid sra;
-        alu_SRL:    tagged Valid srl;
-        default:    tagged Invalid;
-    endcase;
-endfunction
+export AluCfg, AluIfc(..), mkAlu, Execute(..);
 
 typeclass Execute#(numeric type xlen);
     function Maybe#(Bit#(xlen)) execute(RVALUOperator operator, Bit#(xlen) operand1, Bit#(xlen) operand2);
 endtypeclass
 
 instance Execute#(32);
-    function execute = execute32;
+    function Maybe#(Bit#(32)) execute(RVALUOperator operator, Bit#(32) operand1, Bit#(32) operand2);
+        let sum         = operand1 + operand2;
+        let difference  = operand1 - operand2;
+        let bitwise_and = operand1 & operand2;
+        let bitwise_or  = operand1 | operand2;
+        let bitwise_xor = operand1 ^ operand2;
+        let sltu        = (operand1 < operand2 ? 1 : 0);
+        let slt         = (begin
+            Int#(32) signedOperand1 = unpack(pack(operand1));
+            Int#(32) signedOperand2 = unpack(pack(operand2));
+            (signedOperand1 < signedOperand2 ? 1 : 0);
+        end);    
+
+        let sll     = operand1 << operand2[4:0];
+        let sra     = signedShiftRight(operand1, operand2[4:0]);
+        let srl     = operand1 >> operand2[4:0];
+
+        return case(operator)
+            alu_ADD:    tagged Valid sum;
+            alu_SUB:    tagged Valid difference;
+            alu_AND:    tagged Valid bitwise_and;
+            alu_OR:     tagged Valid bitwise_or;
+            alu_XOR:    tagged Valid bitwise_xor;
+            alu_SLTU:   tagged Valid sltu;
+            alu_SLT:    tagged Valid slt;
+            alu_SLL:    tagged Valid sll;
+            alu_SRA:    tagged Valid sra;
+            alu_SRL:    tagged Valid srl;
+            default:    tagged Invalid;
+        endcase;
+    endfunction
 endinstance
 
 instance Execute#(64);
-    function execute = execute64;
-endinstance
+    function Maybe#(Bit#(64)) execute(RVALUOperator operator, Bit#(64) operand1, Bit#(64) operand2);
+        let sum         = operand1 + operand2;
+        let difference  = operand1 - operand2;
+        let bitwise_and = operand1 & operand2;
+        let bitwise_or  = operand1 | operand2;
+        let bitwise_xor = operand1 ^ operand2;
+        let sltu        = (operand1 < operand2 ? 1 : 0);
+        let slt         = (begin
+            Int#(64) signedOperand1 = unpack(pack(operand1));
+            Int#(64) signedOperand2 = unpack(pack(operand2));
+            (signedOperand1 < signedOperand2 ? 1 : 0);
+        end);    
 
-instance Execute#(n);
-    function execute = tagged Invalid;
+        let sll     = operand1 << operand2[5:0];
+        let sra     = signedShiftRight(operand1, operand2[5:0]);
+        let srl     = operand1 >> operand2[5:0];
+
+        return case(operator)
+            alu_ADD:    tagged Valid sum;
+            alu_SUB:    tagged Valid difference;
+            alu_AND:    tagged Valid bitwise_and;
+            alu_OR:     tagged Valid bitwise_or;
+            alu_XOR:    tagged Valid bitwise_xor;
+            alu_SLTU:   tagged Valid sltu;
+            alu_SLT:    tagged Valid slt;
+            alu_SLL:    tagged Valid sll;
+            alu_SRA:    tagged Valid sra;
+            alu_SRL:    tagged Valid srl;
+            default:    tagged Invalid;
+        endcase;
+    endfunction
 endinstance
 
 typedef struct {
@@ -94,51 +86,12 @@ interface AluIfc#(numeric type xlen);
     method Maybe#(Bit#(xlen)) execute(RVALUOperator operator, Bit#(xlen) operand1, Bit#(xlen) operand2);
 endinterface
 
-module mkAlu#(AluCfg#(xlen) cfg)(AluIfc#(xlen));
+module mkAlu#(AluCfg#(xlen) cfg)(AluIfc#(xlen))
+    provisos(
+        Execute#(xlen)
+    );
+
     method Maybe#(Bit#(xlen)) execute(RVALUOperator operator, Bit#(xlen) operand1, Bit#(xlen) operand2);
         return execute(operator, operand1, operand2);
-
-        // return case(operator)
-        //     alu_ADD:    tagged Valid (operand1 + operand2);
-        //     alu_SUB:    tagged Valid (operand1 - operand2);
-        //     alu_AND:    tagged Valid (operand1 & operand2);
-        //     alu_OR:     tagged Valid (operand1 | operand2);
-        //     alu_XOR:    tagged Valid (operand1 ^ operand2);
-        //     alu_SLTU:   tagged Valid setLessThanUnsigned(operand1, operand2);
-        //     alu_SLT:    tagged Valid setLessThan(operand1, operand2);
-
-        //     alu_SLL:    (xlen == 32 ? tagged Valid (operand1 << operand2[4:0]) : tagged Invalid);
-        //     alu_SRA:    (xlen == 32 ? tagged Valid signedShiftRight(operand1, operand2[4:0]) : tagged Invalid);
-        //     alu_SRL:    (xlen == 32 ? tagged Valid (operand1 >> operand2[4:0]) : tagged Invalid);
-
-            // end else if (xlen == 64) begin
-            //     alu_SLL:    tagged Valid (operand1 << operand2[5:0]);
-            //     alu_SRA:    tagged Valid signedShiftRight(operand1, operand2[5:0]);
-            //     alu_SRL:    tagged Valid (operand1 >> operand2[5:0]);
-
-            //     alu_ADD32: begin
-            //         let result = operand1[31:0] + operand2[31:0];
-            //         return tagged Valid signExtend(result[31:0]);
-            //     end
-            //     alu_SUB32: begin
-            //         let result = (operand1[31:0] - operand2[31:0]);
-            //         return tagged Valid signExtend(result[31:0]);
-            //     end
-            //     alu_SLL32: begin
-            //         let result = (operand1[31:0] << operand2[4:0]);
-            //         return tagged Valid signExtend(result[31:0]);
-            //     end
-            //     alu_SRA32: begin
-            //         let result = signedShiftRight(operand1[31:0], operand2[4:0]);
-            //         return tagged Valid signExtend(result[31:0]);
-            //     end
-            //     alu_SRL32: begin
-            //         let result = (operand1[31:0] >> operand2[4:0]);
-            //         return tagged Valid signExtend(result[31:0]);
-            //     end
-            // end
-
-        //     default: tagged Invalid;
-        // endcase;
     endmethod
 endmodule

src/Cpu/Alu_tb.bsv

@@ -0,0 +1,44 @@
+import Alu::*;
+import IsaCfg::*;
+import RV_ISA::*;
+
+import Assert::*;
+
+module mkTopModule(Empty);
+    Reg#(Bit#(20)) stepNumber <- mkReg(0);
+
+    // 32 bit ALU
+    AluCfg#(32) alucfg32 = AluCfg {
+    };
+    AluIfc#(32) alu32 <- mkAlu(alucfg32);
+
+    // 64 bit ALU
+    AluCfg#(64) alucfg64 = AluCfg {
+    };
+    AluIfc#(64) alu64 <- mkAlu(alucfg64);
+
+    (* no_implicit_conditions *)
+    rule test;
+        case(stepNumber)
+            0: begin
+                Maybe#(Bit#(32)) result32 = execute(alu_ADD, 3, 1);
+                dynamicAssert(isValid(result32), "ALU32 - add returned invalid");
+                dynamicAssert(result32.Valid == 4, "ALU32 - add result incorrect");
+
+                Maybe#(Bit#(64)) result64 = execute(alu_ADD, 3, 1);
+                dynamicAssert(isValid(result64), "ALU64 - add incorrect");
+                dynamicAssert(result32.Valid == 4, "ALU64 - add result incorrect");
+            end
+
+            default: begin
+                dynamicAssert(stepNumber == 1, "ALU - not all tests run");
+                $display(">>>PASS");
+                $finish();
+            end
+        endcase
+    endrule
+
+    rule increment_step_number;
+        stepNumber <= stepNumber + 1;
+    endrule
+endmodule

src/Cpu/CSRs/MachineISA.bsv

@@ -0,0 +1,129 @@
+import IsaCfg::*;
+
+import GetPut::*;
+
+typedef Bit#(2) MXL;
+MXL mxl_32bit  = 2'b01;
+MXL mxl_64bit  = 2'b10;
+MXL mxl_128bit = 2'b11;
+
+typedef struct {
+    Bool extZ;      // ** RESERVED **
+    Bool extY;      // ** RESERVED **
+    Bool extX;      // Non-standard extensions present
+    Bool extW;      // ** RESERVED **
+    Bool extV;      // Vector extension
+    Bool extU;      // User mode implemented
+    Bool extT;      // ** RESERVED **
+    Bool extS;      // Supervisor mode implemented
+    Bool extR;      // ** RESERVED **
+    Bool extQ;      // Quad precision floating-point extension
+    Bool extP;      // Packed-SIMD extension
+    Bool extO;      // ** RESERVED **
+    Bool extN;      // User level interrupts extension
+    Bool extM;      // Integer multiply/divide extension
+    Bool extL;      // ** RESERVED **
+    Bool extK;      // ** RESERVED **
+    Bool extJ;      // Dynamically translated language extension
+    Bool extI;      // RV32I/64I/128I base ISA
+    Bool extH;      // Hypervisor extension
+    Bool extG;      // ** RESERVED **
+    Bool extF;      // Single precision floating-point extension
+    Bool extE;      // RV32E base ISA
+    Bool extD;      // Double precision floating-point extension
+    Bool extC;      // Compressed instruction extension
+    Bool extB;      // Bit manipulation extension
+    Bool extA;      // Atomic extension
+} MachineISA deriving(Bits, Eq, FShow);
+
+instance DefaultValue#(MachineISA);
+    defaultValue = MachineISA {
+        extA: False,
+        extB: False,
+        extC: False,
+        extD: False,
+        extE: False,
+        extF: False,
+        extG: False,
+        extH: False,
+        extI: True,     // RV32I/64I/128I base ISA
+        extJ: False,
+        extK: False,
+        extL: False,
+        extM: False,
+        extN: False,
+        extO: False,
+        extP: False,
+        extQ: False,
+        extR: False,
+        extS: False,
+        extT: False,
+        extU: False,
+        extV: False,
+        extW: False,
+        extX: False,
+        extY: False,
+        extZ: False
+    };
+endinstance
+
+interface MachineISAIfc#(numeric type xlen);
+    method Bit#(xlen) pack;
+    interface Get#(MachineISA) getMachineISA;
+    interface Put#(MachineISA) putMachineISA;
+endinterface
+
+module mkMachineISA#(IsaCfg#(xlen) cfg)(MachineISAIfc#(xlen))
+    provisos(
+        Add#(a__, 26, xlen),
+        Add#(b__, 2, xlen)
+    );
+    function MachineISA getMISA;
+        MachineISA misa_ = defaultValue;
+
+        // Check for user level interrupts
+        if (cfg.extN) begin
+            misa_.extN = True;
+        end
+
+        // Check for supervisor mode support.
+        if (cfg.extS) begin
+            misa_.extS = True;
+        end
+
+        // Check for user mode support.
+        if (cfg.extU) begin
+            misa_.extU = True;
+        end
+
+        return misa_;
+    endfunction
+
+    function MXL getMXL;
+        MXL mxl = fromInteger((log2(valueof(xlen))) - 4); 
+        return mxl;
+    endfunction
+
+    method Bit#(xlen) pack;
+        Bit#(xlen) misa = 0;
+
+        misa[valueof(xlen)-1:valueof(xlen)-2] = getMXL;
+
+        Bit#(26) extensions = pack(getMISA);
+        misa[25:0] = extensions;
+
+        return misa;
+    endmethod
+
+    interface Get getMachineISA;
+        method ActionValue#(MachineISA) get;
+            return getMISA;
+        endmethod
+    endinterface
+
+    interface Put putMachineISA;
+        method Action put(MachineISA misa);
+            // Writing to MISA not supported
+        endmethod
+    endinterface
+endmodule

src/Cpu/CSRs/MachineISA.bsv.remove

@@ -1,179 +0,0 @@
-import IsaCfg::*;
-
-import GetPut::*;
-
-typedef Bit#(2) MXL;
-MXL mxl_32bit  = 2'b01;
-MXL mxl_64bit  = 2'b10;
-MXL mxl_128bit = 2'b11;
-
-typedef struct {
-    Bool extA;      // Atomic extension
-    Bool extB;      // Bit manipulation extension
-    Bool extC;      // Compressed instruction extension
-    Bool extD;      // Double precision floating-point extension
-    Bool extE;      // RV32E base ISA
-    Bool extF;      // Single precision floating-point extension
-    Bool extG;      // ** RESERVED **
-    Bool extH;      // Hypervisor extension
-    Bool extI;      // RV32I/64I/128I base ISA
-    Bool extJ;      // Dynamically translated language extension
-    Bool extK;      // ** RESERVED **
-    Bool extL;      // ** RESERVED **
-    Bool extM;      // Integer multiply/divide extension
-    Bool extN;      // User level interrupts extension
-    Bool extO;      // ** RESERVED **
-    Bool extP;      // Packed-SIMD extension
-    Bool extQ;      // Quad precision floating-point extension
-    Bool extR;      // ** RESERVED **
-    Bool extS;      // Supervisor mode implemented
-    Bool extT;      // ** RESERVED **
-    Bool extU;      // User mode implemented
-    Bool extV;      // Vector extension
-    Bool extW;      // ** RESERVED **
-    Bool extX;      // Non-standard extensions present
-    Bool extY;      // ** RESERVED **
-    Bool extZ;      // ** RESERVED **
-} MachineISA#(numeric type xlen);
-
-instance DefaultValue#(MachineISA#(xlen));
-    defaultValue = MachineISA {
-        extA: False,
-        extB: False,
-        extC: False,
-        extD: False,
-        extE: False,
-        extF: False,
-        extG: False,
-        extH: False,
-        extI: True,     // RV32I/64I/128I base ISA
-        extJ: False,
-        extK: False,
-        extL: False,
-        extM: False,
-        extN: False,
-        extO: False,
-        extP: False,
-        extQ: False,
-        extR: False,
-        extS: False,
-        extT: False,
-        extU: False,
-        extV: False,
-        extW: False,
-        extX: False,
-        extY: False,
-        extZ: False
-    };
-endinstance
-
-instance Bits#(MachineISA#(64), 64);
-    function Bit#(64) pack(MachineISA#(64) misa);
-        MXL mxl = mxl_64bit;
-        return {
-            mxl,
-            36'b0,
-            pack(misa.extZ),
-            pack(misa.extY),
-            pack(misa.extX),
-            pack(misa.extW),
-            pack(misa.extV),
-            pack(misa.extU),
-            pack(misa.extT),
-            pack(misa.extS),
-            pack(misa.extR),
-            pack(misa.extQ),
-            pack(misa.extP),
-            pack(misa.extO),
-            pack(misa.extN),
-            pack(misa.extM),
-            pack(misa.extL),
-            pack(misa.extK),
-            pack(misa.extJ),
-            pack(misa.extI),
-            pack(misa.extH),
-            pack(misa.extH),
-            pack(misa.extF),
-            pack(misa.extE),
-            pack(misa.extD),
-            pack(misa.extC),
-            pack(misa.extB),
-            pack(misa.extA)           
-        };
-    endfunction
-
-    function MachineISA#(64) unpack(Bit#(64) value);
-        return defaultValue;
-    endfunction
-endinstance
-
-instance Bits#(MachineISA#(32), 32);
-    function Bit#(32) pack(MachineISA#(32) misa);
-        MXL mxl = mxl_32bit;
-        return {
-            mxl,
-            4'b0,
-            pack(misa.extZ),
-            pack(misa.extY),
-            pack(misa.extX),
-            pack(misa.extW),
-            pack(misa.extV),
-            pack(misa.extU),
-            pack(misa.extT),
-            pack(misa.extS),
-            pack(misa.extR),
-            pack(misa.extQ),
-            pack(misa.extP),
-            pack(misa.extO),
-            pack(misa.extN),
-            pack(misa.extM),
-            pack(misa.extL),
-            pack(misa.extK),
-            pack(misa.extJ),
-            pack(misa.extI),
-            pack(misa.extH),
-            pack(misa.extH),
-            pack(misa.extF),
-            pack(misa.extE),
-            pack(misa.extD),
-            pack(misa.extC),
-            pack(misa.extB),
-            pack(misa.extA)           
-        };
-    endfunction
-
-    function MachineISA#(32) unpack(Bit#(32) value);
-        return defaultValue;
-    endfunction
-endinstance
-
-interface MachineISAIfc#(numeric type xlen);
-    interface Get#(MachineISA#(xlen)) getMachineISA;
-    interface Put#(MachineISA#(xlen)) putMachineISA;
-endinterface
-
-module mkMachineISA#(IsaCfg#(xlen) cfg)(MachineISAIfc#(xlen));
-    interface Get getMachineISA;
-        method ActionValue#(MachineISA#(xlen)) get;
-            MachineISA#(xlen) misa_ = defaultValue;
-
-            // Check for user mode support.
-            if (cfg.u_mode_supported) begin
-                misa_.extU = True;
-            end
-
-            // Check for supervisor mode support.
-            if (cfg.s_mode_supported) begin
-                misa_.extS = True;
-            end
-
-            return misa_;
-        endmethod
-    endinterface
-
-    interface Put putMachineISA;
-        method Action put(MachineISA#(xlen) misa);
-            // Writing to MISA not supported
-        endmethod
-    endinterface
-endmodule

src/Cpu/CSRs/MachineISA_tb.bsv

@@ -0,0 +1,49 @@
+import DecodeStage::*;
+import IsaCfg::*;
+import MachineISA::*;
+
+import Assert::*;
+
+module mkTopModule(Empty);
+    Reg#(Bit#(20)) stepNumber <- mkReg(0);
+
+    IsaCfg#(32) rv32i_cfg = IsaCfg {
+        extN: False,
+        extS: False,
+        extU: False
+    };
+    MachineISAIfc#(32) rv32i <- mkMachineISA(rv32i_cfg);
+
+    IsaCfg#(64) rv64i_cfg = IsaCfg {
+        extN: False,
+        extS: False,
+        extU: False
+    };
+    MachineISAIfc#(64) rv64i <- mkMachineISA(rv64i_cfg);
+
+    (* no_implicit_conditions *)
+    rule test;
+        case(stepNumber)
+            0: begin
+                let misa = rv32i.pack;
+                dynamicAssert(misa == 32'b01_0000_00000000000000000100000000, "MachineISA RV32I invalid");
+            end
+
+            1: begin
+                let misa = rv64i.pack;
+                $display("MISA: %b", misa);
+                dynamicAssert(misa == 64'b10_000000000000000000000000000000000000_00000000000000000100000000, "MachineISA RV64I invalid");
+            end
+
+            default: begin
+                dynamicAssert(stepNumber == 2, "MachineISA - not all tests run");
+                $display(">>>PASS");
+                $finish();
+            end
+        endcase
+    endrule
+
+    rule increment_step_number;
+        stepNumber <= stepNumber + 1;
+    endrule
+endmodule

src/Cpu/CSRs/MachineInformation.bsv

@@ -1,5 +1,3 @@
-export MachineInformationCfg(..);
-
 typedef struct {
     Bit#(32)   mvendorid;
     Bit#(xlen) marchid;

src/Cpu/CSRs/MachineStatus copy.bsv

@@ -1,180 +0,0 @@
-import GetPut::*;
-
-import IsaCfg::*;
-import RV_ISA::*;
-
-typedef Bit#(2) XLENEncoding;
-XLENEncoding xlen_32  = 2'b01;
-XLENEncoding xlen_64  = 2'b10;
-XLENEncoding xlen_128 = 2'b11;
-
-typedef Bit#(2) FSVSState;
-FSVSState fsvs_OFF     = 2'b00;
-FSVSState fsvs_INITIAL = 2'b01;
-FSVSState fsvs_CLEAN   = 2'b10;
-FSVSState fsvs_DIRTY   = 2'b11;
-
-typedef Bit#(2) XSState;
-XSState xs_ALL_OFF               = 2'b00;
-XSState xs_NONE_DIRTY_OR_CLEAN   = 2'b01;
-XSState xs_NONE_DIRTY_SOME_CLEAN = 2'b10;
-XSState xs_SOME_DIRTY            = 2'b11;
-
-typedef struct {
-    Bool sie;               // Supervisor Interrupt Enable
-    Bool mie;               // Machine Interrupt Enable
-    Bool spie;              // Supervisor Mode Interupts Enabled During Trap
-    Bool ube;               // User Mode Data Accesses are Big Endian
-    Bool mpie;              // Machine Mode Interrupts Enabled During Trap
-    Bool spp;               // Supervisor Previous Privilege Mode
-    FSVSState vs;           // Vector Extension State
-    RVPrivilegeLevel mpp;   // Machine Previous Privilege Level
-    FSVSState fs;           // Floating Point Status
-    XSState xs;             // User Mode Extension Status
-    Bool mprv;              // Modify Privilege Mode For Loads/Stores
-    Bool sum;               // Permit Supervisor User Memory Access
-    Bool mxr;               // Make Executable Pages Readable
-    Bool tvm;               // Trap Virtual Memory Management Accesses
-    Bool tw;                // Timeout-Wait
-    Bool tsr;               // Trap SRET Instruction
-
-    XLENEncoding uxl;       // User Mode XLEN value (RV64 only)
-    XLENEncoding sxl;       // Supervisor Mode XLEN value (RV64 only)
-
-    Bool sbe;               // Supervisor Mode Data Accesses are Big Endian
-    Bool mbe;               // Machine Mode Data Accesses are Big Endian
-} MachineStatus#(numeric type xlen) deriving(Bits, Eq);
-
-instance DefaultValue#(MachineStatus#(xlen));
-    defaultValue = MachineStatus {
-        sie: False,
-        mie: False,
-        spie: False,
-        ube: False,
-        mpie: False,
-        spp: False,
-        vs: fsvs_OFF,
-        mpp: priv_MACHINE,
-        fs: fsvs_OFF,
-        xs: xs_ALL_OFF,
-        mprv: False,
-        sum: False,
-        mxr: False,
-        tvm: False,
-        tw: False,
-        tsr: False,
-
-        uxl: xlen_64,   // RV64 only
-        sxl: xlen_64,   // RV64 only
-
-        sbe: False,
-        mbe: False
-    };
-endinstance
-
-instance Bits#(MachineStatus#(64), 64);
-    function Bit#(64) pack(MachineStatus#(64) mstatus);
-        Bit#(1) sd = ((mstatus.vs | mstatus.fs | mstatus.xs) == 0 ? 0 : 1);
-        return {
-            sd,
-            25'b0,
-            pack(mstatus.mbe),
-            pack(mstatus.sbe),
-            pack(mstatus.sxl),
-            pack(mstatus.uxl),
-            9'b0,
-            pack(mstatus.tsr),
-            pack(mstatus.tw),
-            pack(mstatus.tvm),
-            pack(mstatus.mxr),
-            pack(mstatus.sum),
-            pack(mstatus.mprv),
-            pack(mstatus.xs),
-            pack(mstatus.fs),
-            pack(mstatus.mpp),
-            pack(mstatus.vs),
-            pack(mstatus.spp),
-            pack(mstatus.mpie),
-            pack(mstatus.ube),
-            pack(mstatus.spie),
-            1'b0,
-            pack(mstatus.mie),
-            1'b0,
-            pack(mstatus.sie),
-            1'b0
-        };    
-    endfunction
-
-    function MachineStatus#(64) unpack(Bit#(64) value);
-        return defaultValue;
-    endfunction
-endinstance
-
-instance Bits#(MachineStatus#(32), 32);
-    function Bit#(32) pack(MachineStatus#(32) mstatus);
-        Bit#(1) sd = ((mstatus.vs | mstatus.fs | mstatus.xs) == 0 ? 0 : 1);
-        return {
-            sd,
-            8'b0,
-            pack(mstatus.tsr),
-            pack(mstatus.tw),
-            pack(mstatus.tvm),
-            pack(mstatus.mxr),
-            pack(mstatus.sum),
-            pack(mstatus.mprv),
-            pack(mstatus.xs),
-            pack(mstatus.fs),
-            pack(mstatus.mpp),
-            pack(mstatus.vs),
-            pack(mstatus.spp),
-            pack(mstatus.mpie),
-            pack(mstatus.ube),
-            pack(mstatus.spie),
-            1'b0,
-            pack(mstatus.mie),
-            1'b0,
-            pack(mstatus.sie),
-            1'b0
-        };
-    endfunction
-
-    function MachineStatus#(32) unpack(Bit#(32) value);
-        return defaultValue;
-    endfunction
-endinstance
-
-interface MachineStatusIfc#(numeric type xlen);
-    interface Get#(MachineStatus#(xlen)) getMachineStatus;
-    interface Put#(MachineStatus#(xlen)) putMachineStatus;
-endinterface
-
-module mkMachineStatus#(IsaCfg#(xlen) cfg)(MachineStatusIfc#(xlen));
-    Reg#(MachineStatus#(xlen)) mstatus <- mkReg(defaultValue);
-
-    interface Get getMachineStatus = toGet(mstatus);
-    interface Put putMachineStatus;
-        method Action put(MachineStatus#(xlen) value);
-            //
-            // Only MPP, MIE, and MIE are writable.  The rest
-            // are written with defaults
-            //
-            MachineStatus#(xlen) mstatus_ = defaultValue;
-
-            if (cfg.extS) begin
-                mstatus_.mpp = value.mpp;
-            end else begin
-                // Supervisor mode not supported, ensure only USER and MACHINE
-                // mode are set in MPP.
-                RVPrivilegeLevel requestedMPP = value.mpp;
-                if (requestedMPP == priv_USER || requestedMPP == priv_MACHINE) begin
-                    mstatus_.mpp = requestedMPP;
-                end
-            end
-
-            mstatus_.mpie = value.mpie;
-            mstatus_.mie  = value.mie;
-
-            mstatus <= mstatus_;
-        endmethod
-    endinterface
-endmodule

src/Cpu/CSRs/MachineStatus.bsv

@@ -43,7 +43,7 @@ typedef struct {
 
     Bool sbe;               // Supervisor Mode Data Accesses are Big Endian
     Bool mbe;               // Machine Mode Data Accesses are Big Endian
-} MachineStatus;
+} MachineStatus deriving(Bits, Eq, FShow);
 
 instance DefaultValue#(MachineStatus);
     defaultValue = MachineStatus {
@@ -72,8 +72,13 @@ instance DefaultValue#(MachineStatus);
     };
 endinstance
 
-instance Bits#(MachineStatus, 32);
-    function Bit#(32) pack(MachineStatus mstatus);
+typeclass MachineStatusBits#(numeric type xlen);
+    function Bit#(xlen) mstatus_pack(MachineStatus mstatus);
+    function MachineStatus mstatus_unpack(Bit#(xlen) mstatus_packed);
+endtypeclass
+
+instance MachineStatusBits#(32);
+    function Bit#(32) mstatus_pack(MachineStatus mstatus);
         Bit#(1) sd = ((mstatus.vs | mstatus.fs | mstatus.xs) == 0 ? 0 : 1);
         return {
             sd,
@@ -100,13 +105,13 @@ instance Bits#(MachineStatus, 32);
         };
     endfunction
 
-    function MachineStatus unpack(Bit#(32) value);
+    function MachineStatus mstatus_unpack(Bit#(32) mstatus_packed);
         return defaultValue;
     endfunction
 endinstance
 
-instance Bits#(MachineStatus, 64);
-    function Bit#(64) pack(MachineStatus mstatus);
+instance MachineStatusBits#(64);
+    function Bit#(64) mstatus_pack(MachineStatus mstatus);
         Bit#(1) sd = ((mstatus.vs | mstatus.fs | mstatus.xs) == 0 ? 0 : 1);
         return {
             sd,
@@ -134,46 +139,64 @@ instance Bits#(MachineStatus, 64);
             pack(mstatus.mie),
             1'b0,
             pack(mstatus.sie),
-            1'b0
-        };    
+            1'b0        
+        };
     endfunction
 
-    function MachineStatus unpack(Bit#(64) value);
+    function MachineStatus mstatus_unpack(Bit#(64) mstatus_packed);
         return defaultValue;
     endfunction
 endinstance
 
-interface MachineStatus_Ifc;
-    interface Get#(MachineStatus) getMachineStatus;
-    interface Put#(MachineStatus) putMachineStatus;
+interface MachineStatusIfc#(numeric type xlen);
+    method Action beginTrap(RVPrivilegeLevel currentPriv);
+    method Bit#(xlen) get;
+    method Action put(Bit#(xlen) newMachineStatus);
 endinterface
 
-module mkMachineStatus#(IsaCfg#(xlen) cfg)(MachineStatus_Ifc);
-    Reg#(MachineStatus) mstatus <- mkReg(defaultValue);
+module mkMachineStatus#(IsaCfg#(xlen) cfg)(MachineStatusIfc#(xlen))
+    provisos(
+        MachineStatusBits#(xlen)
+    );
+    Reg#(Bit#(xlen)) mstatus <- mkReg(defaultValue);
+    
+    method Action beginTrap(RVPrivilegeLevel currentPriv);
+        // CurPriv => MSTATUS::MPP
+        let mstatus_ = mstatus_unpack(mstatus);
+        mstatus_.mpp  = currentPriv;
 
-    interface Get getMachineStatus = toGet(mstatus);
-    interface Put putMachineStatus;
-        method Action put(MachineStatus value);
-            //
-            // Only MPP, MIE, and MIE are writable.
-            //
-            MachineStatus mstatus_ = mstatus;
+        // MSTATUS::MIE => MSTATUS::MPIE
+        mstatus_.mpie = mstatus_.mie;
+        mstatus_.mie  = False;    // Disable interrupts
 
-            if (cfg.extS) begin
-                mstatus_.mpp = value.mpp;
-            end else begin
-                // Supervisor mode not supported, ensure only USER and MACHINE
-                // mode are set in MPP.
-                RVPrivilegeLevel requestedMPP = value.mpp;
-                if (requestedMPP == priv_USER || requestedMPP == priv_MACHINE) begin
-                    mstatus_.mpp = requestedMPP;
-                end
+        mstatus <= mstatus_pack(mstatus_);
+    endmethod
+
+    method Bit#(xlen) get;
+        return mstatus;
+    endmethod
+
+    method Action put(Bit#(xlen) newMachineStatus);
+        //
+        // Only MPP, MIE, and MIE are writable.
+        //
+        MachineStatus mstatus_ = mstatus_unpack(mstatus);
+        MachineStatus value = mstatus_unpack(newMachineStatus);
+
+        if (cfg.extS) begin
+            mstatus_.mpp = value.mpp;
+        end else begin
+            // Supervisor mode not supported, ensure only USER and MACHINE
+            // mode are set in MPP.
+            RVPrivilegeLevel requestedMPP = value.mpp;
+            if (requestedMPP == priv_USER || requestedMPP == priv_MACHINE) begin
+                mstatus_.mpp = requestedMPP;
             end
+        end
 
-            mstatus_.mpie = value.mpie;
-            mstatus_.mie  = value.mie;
+        mstatus_.mpie = value.mpie;
+        mstatus_.mie  = value.mie;
 
-            mstatus <= mstatus_;
-        endmethod
-    endinterface
+        mstatus <= mstatus_pack(mstatus_);
+    endmethod
 endmodule

src/Cpu/CSRs/MachineStatus_tb.bsv

@@ -0,0 +1,29 @@
+import MachineStatus::*;
+import IsaCfg::*;
+
+import Assert::*;
+
+module mkTopModule(Empty);
+    Reg#(Bit#(20)) stepNumber <- mkReg(0);
+
+    IsaCfg#(32) rv32icfg = defaultValue;
+    MachineStatusIfc#(32) rv32i <- mkMachineStatus(rv32icfg); 
+
+    IsaCfg#(64) rv64icfg = defaultValue;
+    MachineStatusIfc#(64) rv64i <- mkMachineStatus(rv64icfg); 
+
+    (* no_implicit_conditions *)
+    rule test;
+        case(stepNumber)
+            default: begin
+                dynamicAssert(stepNumber == 0, "MachineStatus - not all tests run");
+                $display(">>>PASS");
+                $finish();
+            end
+        endcase
+    endrule
+
+    rule increment_step_number;
+        stepNumber <= stepNumber + 1;
+    endrule
+endmodule

src/Cpu/Cpu.bsv

@@ -17,7 +17,7 @@ typedef struct {
 } CpuCfg#(numeric type xlen, numeric type icacheFetchByteCount);
 
 //
-// CpuIfc
+// Cpu
 //
 interface CpuIfc#(numeric type xlen, numeric type icacheFetchByteCount);
     interface Get#(ICacheRequest#(xlen)) getCacheRequest;
@@ -58,7 +58,7 @@ module mkCpu#(CpuCfg#(xlen, icacheFetchByteCount) cfg)(CpuIfc#(xlen, icacheFetch
 
     // General purpose register (GPR) file
     GprFileCfg#(xlen)   gpr_cfg = GprFileCfg {};
-    GprFile#(xlen)      gpr    <- mkGprFile(gpr_cfg);
+    GprFileIfc#(xlen)   gprfile <- mkGprFile(gpr_cfg);
 
     //
     // INITIALIZATION
@@ -69,7 +69,7 @@ module mkCpu#(CpuCfg#(xlen, icacheFetchByteCount) cfg)(CpuIfc#(xlen, icacheFetch
         // Zero the GPRs
         //
         for (gprInitIndex <= 0; gprInitIndex <= 32; gprInitIndex <= gprInitIndex + 1)
-            gpr.gprWritePort.write(truncate(gprInitIndex), 0);
+            gprfile.gprWritePort.write(truncate(gprInitIndex), 0);
 
         state <= FETCH;
     endseq);

src/Cpu/CsrFile.bsv

@@ -5,6 +5,7 @@ import Trap::*;
 
 import IsaCfg::*;
 import MachineInformation::*;
+import MachineISA::*;
 import MachineStatus::*;
 import RV_ISA::*;
 
@@ -18,18 +19,18 @@ typedef struct {
 } CsrWriteResult deriving(Bits, Eq, FShow);
 
 interface CsrReadPort#(numeric type xlen);
-    method ActionValue#(CsrReadResult#(xlen)) read(RVCsrIndex index);
+    method ActionValue#(CsrReadResult#(xlen)) read(RVCSRIndex index);
 endinterface
 
 interface CsrWritePort#(numeric type xlen);
-    method ActionValue#(CsrWriteResult) write(RVCsrIndex index, Bit#(xlen) value);
+    method ActionValue#(CsrWriteResult) write(RVCSRIndex index, Bit#(xlen) value);
 endinterface
 
 interface CsrWritePermission;
-    method Bool isWriteable(RVCsrIndex index);
+    method Bool isWriteable(RVCSRIndex index);
 endinterface
 
-interface CsrFile#(numeric type xlen);
+interface CsrFileIfc#(numeric type xlen);
     method Action incrementCycleCounters;
     method Action incrementInstructionsRetiredCounter;
 
@@ -37,14 +38,14 @@ interface CsrFile#(numeric type xlen);
     interface CsrWritePort#(xlen)   csrWritePort;
     interface CsrWritePermission    csrWritePermission;
 
-    interface TrapController#(xlen) trapController;
+    interface TrapControllerIfc#(xlen) trapController;
 endinterface
 
-typedef struct {
-    IsaCfg#(xlen) isa_cfg;
-} CsrFileCfg#(numeric type xlen);
-
-module mkCsrFile#(CsrFileCfg#(xlen) cfg)(CsrFile#(xlen));
+module mkCsrFile#(IsaCfg#(xlen) cfg)(CsrFileIfc#(xlen))
+    provisos(
+        Add#(xlen, 0, 32),
+        Add#(xlen, 0, 64)
+    );
     Reg#(RVPrivilegeLevel)  currentPriv        <- mkReg(priv_MACHINE);
 
     // Counters
@@ -64,19 +65,17 @@ module mkCsrFile#(CsrFileCfg#(xlen) cfg)(CsrFile#(xlen));
     };
 
     MachineStatusIfc#(xlen)     mstatus             <- mkMachineStatus(cfg);
-/*
+    MachineISAIfc#(xlen)        misa                <- mkMachineISA(cfg);
     ReadOnly#(Bit#(xlen))       mcycle              <- mkReadOnly(truncate(cycleCounter));
     ReadOnly#(Bit#(xlen))       mtimer              <- mkReadOnly(truncate(timeCounter));
     ReadOnly#(Bit#(xlen))       minstret            <- mkReadOnly(truncate(retiredCounter));
-*/
 
-/*
     if (valueof(xlen) == 32) begin
         ReadOnly#(Bit#(xlen))   mcycleh             <- mkReadOnly(truncateLSB(cycleCounter));
         ReadOnly#(Bit#(xlen))   mtimeh              <- mkReadOnly(truncateLSB(timeCounter));
         ReadOnly#(Bit#(xlen))   minstreth           <- mkReadOnly(truncateLSB(retiredCounter));
     end
-*/
+
     Reg#(Bit#(xlen))        mcause                  <- mkReg(0);
     Reg#(Bit#(xlen))        mtvec                   <- mkReg('hC0DEC0DE);
     Reg#(Bit#(xlen))        mepc                    <- mkReg(0);
@@ -90,7 +89,7 @@ module mkCsrFile#(CsrFileCfg#(xlen) cfg)(CsrFile#(xlen));
     Reg#(Bit#(xlen))        sideleg                 <- mkReg(0);
     Reg#(Bit#(xlen))        sedeleg                 <- mkReg(0);
 
-    function Bool isWARLIgnore(RVCsrIndex index);
+    function Bool isWARLIgnore(RVCSRIndex index);
         Bool result = False;
         if ((index >= csr_PMPADDR0 && index <= csr_PMPADDR63) ||
             (index >= csr_PMPCFG0  && index <= csr_PMPCFG15) ||
@@ -103,8 +102,8 @@ module mkCsrFile#(CsrFileCfg#(xlen) cfg)(CsrFile#(xlen));
         return result;
     endfunction
 
-    function RVCsrIndex getIndex(RVPrivilegeLevel privilege_level, RVCsrIndexOffset offset);
-        RVCsrIndex index = 0;
+    function RVCSRIndex getIndex(RVPrivilegeLevel privilege_level, RVCSRIndexOffset offset);
+        RVCSRIndex index = 0;
         index[9:8] = privilege_level[1:0];
         index[7:0] = offset;
         return index;
@@ -115,7 +114,7 @@ module mkCsrFile#(CsrFileCfg#(xlen) cfg)(CsrFile#(xlen));
         let trap_privilege_level = priv_MACHINE;
 
         if (currentPriv < priv_MACHINE) begin
-            if (cfg.s_mode_supported) begin    // S mode supported?
+            if (cfg.extS) begin    // S mode supported?
                 // See if this trap should be delegated to SUPERVISOR mode
                 let delegated = (trap.isInterrupt ? 
                     (mideleg[trap.cause] == 0 ? False : True) :
@@ -126,7 +125,7 @@ module mkCsrFile#(CsrFileCfg#(xlen) cfg)(CsrFile#(xlen));
 
                     // If the current priv mode is U, and user mode traps are supported,
 	                // then consult sedeleg/sideleg to determine if delegated to USER mode.                    
-                    if (currentPriv == priv_USER && cfg.u_level_interrupts_supported) begin
+                    if (currentPriv == priv_USER && cfg.extU) begin
                         delegated = (trap.isInterrupt ? 
                             (sideleg[trap.cause] == 0 ? False : True) :
                             (sedeleg[trap.cause] == 0 ? False : True));
@@ -139,7 +138,7 @@ module mkCsrFile#(CsrFileCfg#(xlen) cfg)(CsrFile#(xlen));
             end else begin // S mode *NOT* supported
                 // If user mode traps are supported, then consult sedeleg/sideleg to determine 
                 // if delegated to USER mode.                    
-                if (cfg.u_level_interrupts_supported) begin
+                if (cfg.extU) begin
                     let delegated = (trap.isInterrupt ? 
                         (mideleg[trap.cause] == 0 ? False : True) :
                         (medeleg[trap.cause] == 0 ? False : True));
@@ -157,9 +156,9 @@ module mkCsrFile#(CsrFileCfg#(xlen) cfg)(CsrFile#(xlen));
     //
     // readInternal
     //
-    function ActionValue#(CsrReadResult#(xlen)) readInternal(RVCsrIndex index);
+    function ActionValue#(CsrReadResult#(xlen)) readInternal(RVCSRIndex index);
         actionvalue
-            let result = CsrReadResult {
+            CsrReadResult#(xlen) result = CsrReadResult {
                 value: 0,
                 denied: False
             };
@@ -167,14 +166,12 @@ module mkCsrFile#(CsrFileCfg#(xlen) cfg)(CsrFile#(xlen));
             if (!isWARLIgnore(index)) begin
                 case(index)
                     // Machine Information Registers (MRO)
-/*
                     csr_MVENDORID:  result.value = extend(machineInfoCfg.mvendorid);
-*/
                     csr_MARCHID:    result.value = machineInfoCfg.marchid;
                     csr_MIMPID:     result.value = machineInfoCfg.mimpid;
                     csr_MHARTID:    result.value = machineInfoCfg.mhartid;
 
-                    csr_MISA:       result.value = pack(cfg);
+                    csr_MISA:       result.value = misa.pack;
 
                     csr_MCAUSE:     result.value = mcause;
                     csr_MTVEC:      result.value = mtvec;
@@ -183,15 +180,12 @@ module mkCsrFile#(CsrFileCfg#(xlen) cfg)(CsrFile#(xlen));
                     csr_MIDELEG:    result.value = mideleg;
                     csr_MEDELEG:    result.value = medeleg;
 
-                    csr_MSTATUS:    begin
-                        let mstatus_ <- mstatus.getMachineStatus.get;
-                        result.value = pack(mstatus_);
-                    end
-/*
+                    csr_MSTATUS:    result.value = mstatus.get;
+
                     csr_MCYCLE, csr_CYCLE: begin
                                     result.value = mcycle;
                     end
-*/
+
                     csr_MSCRATCH:   result.value = mscratch;
                     csr_MIP:        result.value = mip;
                     csr_MIE:        result.value = mie;
@@ -216,7 +210,7 @@ module mkCsrFile#(CsrFileCfg#(xlen) cfg)(CsrFile#(xlen));
     //
     // writeInternal
     //
-    function ActionValue#(CsrWriteResult) writeInternal(RVCsrIndex index, Bit#(xlen) value);
+    function ActionValue#(CsrWriteResult) writeInternal(RVCSRIndex index, Bit#(xlen) value);
         actionvalue
             let result = CsrWriteResult {
                 denied: False
@@ -232,7 +226,7 @@ module mkCsrFile#(CsrFileCfg#(xlen) cfg)(CsrFile#(xlen));
                         // No-Op
                     end
                     csr_MSCRATCH: mscratch      <= value;
-                    csr_MSTATUS:  mstatus.unpack(value);
+                    csr_MSTATUS:  mstatus.put(value);
                     csr_MTVAL:    mtval         <= value;
                     csr_MTVEC:    mtvec         <= value;
                     csr_MIE:      mie           <= value;
@@ -252,14 +246,14 @@ module mkCsrFile#(CsrFileCfg#(xlen) cfg)(CsrFile#(xlen));
         endactionvalue
     endfunction
 
-    function ActionValue#(CsrReadResult#(xlen)) readWithOffset1(RVPrivilegeLevel privilegeLevel, RVCsrIndexOffset offset);
+    function ActionValue#(CsrReadResult#(xlen)) readWithOffset1(RVPrivilegeLevel privilegeLevel, RVCSRIndexOffset offset);
         actionvalue
             let csrReadResult <- readInternal(getIndex(privilegeLevel, offset));
             return csrReadResult;
         endactionvalue
     endfunction      
 
-    function ActionValue#(CsrWriteResult) writeWithOffset1(RVPrivilegeLevel privilegeLevel, RVCsrIndexOffset offset, Bit#(xlen) value);
+    function ActionValue#(CsrWriteResult) writeWithOffset1(RVPrivilegeLevel privilegeLevel, RVCSRIndexOffset offset, Bit#(xlen) value);
         actionvalue
             let csrWriteResult <- writeInternal(getIndex(privilegeLevel, offset), value);
             return csrWriteResult;
@@ -279,7 +273,7 @@ module mkCsrFile#(CsrFileCfg#(xlen) cfg)(CsrFile#(xlen));
     // CsrReadport
     //
     interface CsrReadPort csrReadPort;
-        method ActionValue#(CsrReadResult#(xlen)) read(RVCsrIndex index);
+        method ActionValue#(CsrReadResult#(xlen)) read(RVCSRIndex index);
             let result = CsrReadResult {
                 value: 0,
                 denied: True
@@ -297,7 +291,7 @@ module mkCsrFile#(CsrFileCfg#(xlen) cfg)(CsrFile#(xlen));
     // CsrWritePort
     //
     interface CsrWritePort csrWritePort;
-        method ActionValue#(CsrWriteResult) write(RVCsrIndex index, Bit#(xlen) value);
+        method ActionValue#(CsrWriteResult) write(RVCSRIndex index, Bit#(xlen) value);
             let result = CsrWriteResult {
                 denied: True
             };
@@ -314,7 +308,7 @@ module mkCsrFile#(CsrFileCfg#(xlen) cfg)(CsrFile#(xlen));
     // CsrWritePermission
     //
     interface CsrWritePermission csrWritePermission;
-        method Bool isWriteable(RVCsrIndex index);
+        method Bool isWriteable(RVCSRIndex index);
             return (currentPriv >= index[9:8] && index[11:10] != 'b11);
         endmethod
     endinterface
@@ -322,28 +316,21 @@ module mkCsrFile#(CsrFileCfg#(xlen) cfg)(CsrFile#(xlen));
     //
     // trapController
     //
-    interface TrapController trapController;
+    interface TrapControllerIfc trapController;
         method ActionValue#(Bit#(xlen)) beginTrap(Bit#(xlen) trapProgramCounter, Trap#(xlen) trap);
             Bit#(xlen) cause = 0;
 
             let trapPrivilegeLevel = getTrapPrivilegeLevel(trap);
-/*
+
             cause = zeroExtend(trap.cause);
             if (!trap.isInterrupt) begin
                 cause[valueOf(xlen)-1] = 1;
             end
-*/
+
             // PC => MEPC
             writeWithOffset1(trapPrivilegeLevel, csr_EPC, trapProgramCounter);  
 
-            // CurPriv => MSTATUS::MPP
-            let mstatus_ <- mstatus.getMachineStatus.get;
-            mstatus_.mpp  = currentPriv;
-
-            // MSTATUS::MIE => MSTATUS::MPIE
-            mstatus_.mpie = mstatus_.mie;
-            mstatus_.mie  = False;    // Disable interrupts
-            mstatus.putMachineStatus.put(mstatus_);
+            mstatus.beginTrap(currentPriv);
 
             // cause => CAUSE
             writeWithOffset1(trapPrivilegeLevel, csr_CAUSE, cause);
@@ -354,14 +341,13 @@ module mkCsrFile#(CsrFileCfg#(xlen) cfg)(CsrFile#(xlen));
             let trapHandler = vectorTableBase;
 
             // Check and handle a vectored trap handler table
-/*
             if (trapHandler[1:0] == 1) begin
                 trapHandler[1:0] = 0;
                 if(trap.isInterrupt) begin
                     trapHandler = trapHandler + extend(4 * trap.cause);
                 end
             end
-*/
+
             currentPriv <= trapPrivilegeLevel;
 
             return trapHandler;
@@ -372,15 +358,14 @@ module mkCsrFile#(CsrFileCfg#(xlen) cfg)(CsrFile#(xlen));
 
             let readStatus <- readWithOffset1(currentPriv, csr_STATUS);
             if (readStatus.denied == False) begin
-/*
-                MachineStatus#(xlen) mstatus = unpack(readStatus.value);
-                let newPrivilegeLevel = mstatus.mpp;
-                mstatus.mie = mstatus.mpie;
-                mstatus.mpie = False;
-*/
+                MachineStatus mstatus_ = mstatus_unpack(readStatus.value);
+                let newPrivilegeLevel = mstatus_.mpp;
+                mstatus_.mie = mstatus_.mpie;
+                mstatus_.mpie = False;
+
                 // Attempt to update MSTATUS.  The current privilege level may prevent this.
-/*
-                let writeStatus <- writeInternal(csr_MSTATUS, pack(mstatus));
+
+                let writeStatus <- writeInternal(csr_MSTATUS, mstatus_pack(mstatus_));
                 if (writeStatus.denied == False) begin
                     currentPriv <= newPrivilegeLevel;
                     readStatus <- readWithOffset1(currentPriv, csr_EPC); 
@@ -388,7 +373,6 @@ module mkCsrFile#(CsrFileCfg#(xlen) cfg)(CsrFile#(xlen));
                         newProgramCounter = readStatus.value;
                     end
                 end
-*/
             end
             return newProgramCounter;        
         endmethod

src/Cpu/CsrFile_tb.bsv

@@ -0,0 +1,23 @@
+import CsrFile::*;
+import IsaCfg::*;
+
+import Assert::*;
+
+module mkTopModule(Empty);
+    Reg#(Bit#(20)) stepNumber <- mkReg(0);
+
+    (* no_implicit_conditions *)
+    rule test;
+        case(stepNumber)
+            default: begin
+                dynamicAssert(stepNumber == 0, "CsrFile - not all tests run");
+                $display(">>>PASS");
+                $finish();
+            end
+        endcase
+    endrule
+
+    rule increment_step_number;
+        stepNumber <= stepNumber + 1;
+    endrule
+endmodule

src/Cpu/DecodeStage.bsv

@@ -0,0 +1,165 @@
+import CsrFile::*;
+import IsaCfg::*;
+import GprFile::*;
+import PipelineRegisters::*;
+import RV_ISA::*;
+import Trap::*;
+
+import GetPut::*;
+
+interface DecodeModuleIfc#(numeric type xlen);
+    method ActionValue#(ID_EX#(xlen)) step(
+        IF_ID#(xlen) if_id, 
+        GprReadPort#(xlen) gprReadPort1, 
+        GprReadPort#(xlen) gprReadPort2,
+        CsrReadPort#(xlen) csrReadPort
+    );
+endinterface
+
+module mkDecodeModule#(IsaCfg#(xlen) cfg)(DecodeModuleIfc#(xlen))
+    provisos(
+        Add#(a__, 20, xlen),
+        Add#(b__, 5, xlen),
+        Add#(c__, 13, xlen),
+        Add#(d__, 21, xlen),
+        Add#(e__, 12, xlen)
+    );
+    function RVGPRIndex extractRs1(Instruction inst);
+        return inst.value[19:15];
+    endfunction
+
+    function RVGPRIndex extractRs2(Instruction inst);
+        return inst.value[24:20];
+    endfunction
+
+    function RVCSRIndex extractCsrIndex(Instruction inst);
+        return inst.value[31:20];
+    endfunction
+
+    function Bit#(xlen) decodeImmediate(Instruction inst);
+        return case(inst.value[6:0])
+            7'b0110111: begin // LUI
+                signExtend(inst.value[31:12]);
+            end
+
+            7'b0010111: begin // AUIPC
+                signExtend(inst.value[31:12]);
+            end
+
+            7'b1101111: begin // JAL
+                signExtend({
+                    inst.value[31],
+                    inst.value[19:12],
+                    inst.value[20],
+                    inst.value[30:21],
+                    1'b0
+                });
+            end
+
+            7'b1100111: begin // JALR
+                signExtend(inst.value[31:20]);
+            end
+
+            7'b1100011: begin // BRANCH
+                signExtend({
+                    inst.value[31],
+                    inst.value[7],
+                    inst.value[30:25],
+                    inst.value[11:8],
+                    1'b0
+                });
+            end
+
+            7'b0000011: begin // LOAD
+                signExtend(inst.value[31:20]);
+            end
+
+            7'b0100011: begin // STORE
+                signExtend({
+                    inst.value[31:25],
+                    inst.value[11:7]
+                });
+            end
+
+            7'b0010011: begin // OPIMM
+                signExtend(inst.value[31:20]);
+            end
+
+            7'b1110011: begin // SYSTEM (CSR)
+                zeroExtend(inst.value[19:15]);  // UIMM stored in RS1
+            end
+
+            default: begin
+                0;
+            end
+        endcase;
+    endfunction
+
+    method ActionValue#(ID_EX#(xlen)) step(
+        IF_ID#(xlen) if_id, 
+        GprReadPort#(xlen) gprReadPort1, 
+        GprReadPort#(xlen) gprReadPort2,
+        CsrReadPort#(xlen) csrReadPort
+    );
+        ID_EX#(xlen) id_ex = defaultValue;
+
+        id_ex.common = if_id.common;
+        id_ex.epoch = if_id.epoch;
+        id_ex.npc = if_id.npc;
+
+        // Read GPRs
+        let rs1 = extractRs1(if_id.common.ir);
+        let rs2 = extractRs2(if_id.common.ir);
+        id_ex.a = gprReadPort1.read(rs1);
+        id_ex.b = gprReadPort2.read(rs2);
+
+        // Decode immediate
+        id_ex.imm = decodeImmediate(if_id.common.ir);
+
+        // CSR read
+        let csrIndex = extractCsrIndex(if_id.common.ir);
+        id_ex.csr <- csrReadPort.read(csrIndex);
+
+        return id_ex;
+    endmethod
+endmodule
+
+interface DecodeStageIfc#(numeric type xlen);
+    interface Put#(IF_ID#(xlen)) put;
+    interface Get#(ID_EX#(xlen)) get;
+endinterface
+
+module mkDecodeStage#(IsaCfg#(xlen) cfg, 
+                      GprReadPort#(xlen) gprReadPort1, 
+                      GprReadPort#(xlen) gprReadPort2, 
+                      CsrReadPort#(xlen) csrReadPort)(DecodeStageIfc#(xlen))
+    provisos(
+        Add#(a__, 20, xlen),
+        Add#(b__, 5, xlen),
+        Add#(c__, 13, xlen),
+        Add#(d__, 21, xlen),
+        Add#(e__, 12, xlen)
+    );
+
+    //
+    // State
+    //
+    Wire#(IF_ID#(xlen)) if_id <- mkWire;
+    Reg#(ID_EX#(xlen))  id_ex <- mkRegU;
+    DecodeModuleIfc#(xlen) decodeModule <- mkDecodeModule(cfg);
+
+    //
+    // Rules
+    //
+    (* no_implicit_conditions *)
+    rule step;
+        let id_ex_ <- decodeModule.step(if_id, gprReadPort1, gprReadPort2, csrReadPort);
+        id_ex <= id_ex_;
+    endrule
+
+    //
+    // Interfaces
+    //
+    interface Put put = toPut(asIfc(if_id));
+    interface Get get = toGet(id_ex);
+endmodule

src/Cpu/DecodeStage_tb.bsv

@@ -0,0 +1,44 @@
+import DecodeStage::*;
+import GprFile::*;
+import IsaCfg::*;
+import PipelineRegisters::*;
+import RV_ISA::*;
+import Trap::*;
+
+import Assert::*;
+
+module mkTopModule(Empty);
+    Reg#(Bit#(20)) stepNumber <- mkReg(0);
+
+    // 32 bit
+    IsaCfg#(32) rv32 = IsaCfg{
+        extN: False,
+        extS: False,
+        extU: False
+    };
+    DecodeModuleIfc#(32) decodeModule32 <- mkDecodeModule(rv32);
+
+    //
+    // GPR
+    //
+    GprFileCfg#(32) gprFileCfg32 = GprFileCfg {
+    };
+    GprFileIfc#(32) gprFile32 <- mkGprFile(gprFileCfg32);
+
+    (* no_implicit_conditions *)
+    rule test;
+        IF_ID#(32) if_id = defaultValue;
+
+        case(stepNumber)
+            default: begin
+                dynamicAssert(stepNumber == 0, "Decode - not all tests run");
+                $display(">>>PASS");
+                $finish();
+            end
+        endcase
+    endrule
+
+    rule increment_step_number;
+        stepNumber <= stepNumber + 1;
+    endrule
+endmodule

src/Cpu/FetchStage.bsv

@@ -1,5 +1,5 @@
 import IsaCfg::*;
-import MemoryTypes::*;
+import MemoryIO::*;
 import PipelineRegisters::*;
 import RV_ISA::*;
 import Trap::*;
@@ -10,34 +10,38 @@ import FIFOF::*;
 import GetPut::*;
 import Memory::*;
 
-interface FetchStage_Ifc#(numeric type xlen);
+typedef ReadOnlyMemoryRequest#(xlen, 32) InstructionMemoryRequest#(numeric type xlen);
+
+interface FetchModuleIfc#(numeric type xlen);
     method ActionValue#(IF_ID#(xlen)) step(PC_IF#(xlen) pc_if);
 
     interface ReadOnlyMemoryClient#(xlen, 32) memoryClient;
 endinterface
 
-module mkFetchStage#(IsaCfg#(xlen) cfg)(FetchStage_Ifc#(xlen));
+module mkFetchModule#(IsaCfg#(xlen) cfg)(FetchModuleIfc#(xlen));
     Reg#(ProgramCounter#(xlen)) updatedPc <- mkRegU; // Holds the updated PC that is calculated when a fetch is issued 
                                                      // that is used to update the PC when the fetch completes.
 
+    Reg#(Epoch) requestEpoch <- mkRegU; // Holds the epoch of the initiating request.
+
     // Memory request output
-    Reg#(Maybe#(ReadOnlyMemoryRequest#(xlen))) inflightMemoryRequest <- mkReg(tagged Invalid);
-    Wire#(ReadOnlyMemoryRequest#(xlen)) memoryRequest <- mkWire;
+    Reg#(Maybe#(InstructionMemoryRequest#(xlen))) inflightMemoryRequest <- mkReg(tagged Invalid);
+    Wire#(InstructionMemoryRequest#(xlen)) memoryRequest <- mkWire;
 
     // Memory response input (FIFO)
-    // Note: This is an unguarded FIFO so status much be checked before attempting to enq() and deq().
-    FIFOF#(ReadOnlyMemoryResponse#(32)) memoryResponses <- mkUGFIFOF1;
+    // Note: This is an unguarded FIFO so status must be checked before attempting to enq() and deq().
+    FIFOF#(FallibleMemoryResponse#(32)) memoryResponses <- mkUGFIFOF1;
 
     //
     // processMemoryResponse - Takes a memory response and returns an IF_ID containing
     //                         the encoded instruction (or a trap if the original request
     //                         was denied by the memory system)
     //
-    function IF_ID#(xlen) processMemoryResponse(ReadOnlyMemoryResponse#(32) response);    
+    function IF_ID#(xlen) processMemoryResponse(FallibleMemoryResponse#(32) response);    
         IF_ID#(xlen) if_id = defaultValue;
         if_id.common.pc = inflightMemoryRequest.Valid.address;
-        if_id.common.isBubble = False;
-        if_id.npc = updatedPc;
+        if_id.npc = updatedPc + 4;
+        if_id.epoch = requestEpoch;
 
         if (!response.accessFault) begin
             if_id.common.ir.value = response.data;
@@ -73,10 +77,18 @@ module mkFetchStage#(IsaCfg#(xlen) cfg)(FetchStage_Ifc#(xlen));
         end else begin
             // No memory request is in flight...
 
-            // Determine the PC the instruction will be fetchted from.  It's either the calculated PC
+            // Determine the PC the instruction will be fetched from.  It's either the calculated PC
             // or a redirected PC (due to a branch, jump, exception, etc)
             ProgramCounter#(xlen) updatedPc_ = fromMaybe(pc_if.pc, pc_if.redirection);
 
+            // If a redirection was specified, reflect that with a change in the epoch.
+            let epoch = pc_if.epoch;
+            if (isValid(pc_if.redirection)) begin
+                epoch = ~epoch;
+            end
+
+            requestEpoch <= epoch;
+
             // Check for a misaligned request
             if (updatedPc_[1:0] != 0) begin
                 // Address request was misaligned...
@@ -87,11 +99,11 @@ module mkFetchStage#(IsaCfg#(xlen) cfg)(FetchStage_Ifc#(xlen));
                 };
                 if_id.common.pc = updatedPc_;
                 if_id.common.trap = tagged Valid(trap);
-                if_id.common.isBubble = False;
             end else begin
                 // Construct a memory request and send it out.
-                ReadOnlyMemoryRequest#(xlen) request = ReadOnlyMemoryRequest {
-                    address: updatedPc_
+                InstructionMemoryRequest#(xlen) request = ReadOnlyMemoryRequest {
+                    address: updatedPc_,
+                    byteen: 'b1111
                 };
                 memoryRequest <= request;
                 inflightMemoryRequest <= tagged Valid request;
@@ -106,10 +118,42 @@ module mkFetchStage#(IsaCfg#(xlen) cfg)(FetchStage_Ifc#(xlen));
     interface ReadOnlyMemoryClient memoryClient;
         interface Get request = toGet(memoryRequest);
         interface Put response;
-            method Action put(ReadOnlyMemoryResponse#(32) response);
+            method Action put(FallibleMemoryResponse#(32) response);
                 dynamicAssert(memoryResponses.notFull, "FetchStage - attempt to put a memory respnose on a full queue");
                 memoryResponses.enq(response);
             endmethod
         endinterface
     endinterface
 endmodule
+
+interface FetchStageIfc#(numeric type xlen);
+    interface Put#(PC_IF#(xlen)) put;
+    interface Get#(IF_ID#(xlen)) get;
+
+    interface ReadOnlyMemoryClient#(xlen, 32) memoryClient;
+endinterface
+
+module mkFetchStage#(IsaCfg#(xlen) cfg)(FetchStageIfc#(xlen));
+    //
+    // State
+    //
+    Wire#(PC_IF#(xlen)) pc_if <- mkWire;
+    Reg#(IF_ID#(xlen))  if_id <- mkRegU;
+    FetchModuleIfc#(xlen) fetchModule <- mkFetchModule(cfg);
+
+    //
+    // Rules
+    //
+    (* no_implicit_conditions *)
+    rule step;
+        let if_id_ <- fetchModule.step(pc_if);
+        if_id <= if_id_;
+    endrule
+
+    //
+    // Interfaces
+    //
+    interface Put put = toPut(asIfc(pc_if));
+    interface Get get = toGet(if_id);
+    interface MemoryClient memoryClient = fetchModule.memoryClient;
+endmodule

src/Cpu/FetchStage_tb.bsv

@@ -1,6 +1,6 @@
 import FetchStage::*;
 import IsaCfg::*;
-import MemoryTypes::*;
+import MemoryIO::*;
 import PipelineRegisters::*;
 import RV_ISA::*;
 import Trap::*;
@@ -20,10 +20,10 @@ module mkTopModule(Empty);
         extS: False,
         extU: False
     };
-    FetchStage_Ifc#(32) fetchStage32 <- mkFetchStage(rv32);
+    FetchModuleIfc#(32) fetchModule32 <- mkFetchModule(rv32);
 
-    FIFOF#(ReadOnlyMemoryRequest#(32)) memoryRequests32 <- mkUGFIFOF1();
-    mkConnection(fetchStage32.memoryClient.request, toPut(asIfc(memoryRequests32)));
+    FIFOF#(InstructionMemoryRequest#(32)) memoryRequests32 <- mkUGFIFOF1();
+    mkConnection(fetchModule32.memoryClient.request, toPut(asIfc(memoryRequests32)));
 
     (* no_implicit_conditions *)
     rule test;
@@ -34,29 +34,29 @@ module mkTopModule(Empty);
             0: begin
                 pc_if.pc = 'h101;
 
-                let if_id <- fetchStage32.step(pc_if);
+                let if_id <- fetchModule32.step(pc_if);
                 dynamicAssert(if_id.common.pc == pc_if.pc, "Fetch - Misaligned instruction trap check - common.pc");
                 dynamicAssert(if_id.common.ir == defaultValue, "Fetch - Misaligned instruction trap check - common.ir");
-                dynamicAssert(!if_id.common.isBubble, "Fetch - Misaligned instruction trap check - common.isBubble");
                 dynamicAssert(isValid(if_id.common.trap), "Fetch - Misaligned instruction trap check - contains trap");
                 dynamicAssert(if_id.common.trap.Valid.cause == exception_INSTRUCTION_ADDRESS_MISALIGNED, "Fetch - Misaligned instruction trap check - cause is misaligned address");
+                dynamicAssert(if_id.npc == defaultValue, "Fetch - Misaligned instruction trap check - NPC incorrect");
             end
 
-            // Memory request denied trap (request submit)
+            // Memory request denied trap (step 1 - request submit)
             1: begin
                 pc_if.pc = 'h100;
 
                 // The fetch should proceed and return a bubble.
-                let if_id <- fetchStage32.step(pc_if);
+                let if_id <- fetchModule32.step(pc_if);
                 dynamicAssert(if_id == defaultValue, "Fetch - Memory request denied trap check - request should return a bubble");
             end
 
-            // Memory request denied trap (request receipt)
+            // Memory request denied trap (step 2 - request receipt)
             2: begin
                 pc_if.pc = 'h100;
 
                 // Ensure the fetch returns a bubble while the memory request is in flight
-                let if_id <- fetchStage32.step(pc_if);
+                let if_id <- fetchModule32.step(pc_if);
                 dynamicAssert(if_id == defaultValue, "Fetch - Memory request denied trap check - request should return a bubble while fetch is in flight");
 
                 dynamicAssert(memoryRequests32.notEmpty, "Fetch - Memory request denied trap check - memory request queue should not be empty");
@@ -64,40 +64,41 @@ module mkTopModule(Empty);
                 memoryRequests32.deq;
 
                 dynamicAssert(memoryRequest.address == 'h100, "Fetch - Memory request denied trap check - memory request should have correct address");
-                fetchStage32.memoryClient.response.put(ReadOnlyMemoryResponse {
+                dynamicAssert(memoryRequest.byteen == 'b1111, "Fetch - Memory request denied trap check - memory request byte enable should be 'b1111");
+                fetchModule32.memoryClient.response.put(FallibleMemoryResponse {
                     data: 'h-1,
                     accessFault: True
                 });
             end
 
-            // Memory request denied trap (return trap check)
+            // Memory request denied trap (step 3 - return trap check)
             3: begin
                 pc_if.pc = 'h100;
 
-                // The fetch should proceed and return a bubble.
-                let if_id <- fetchStage32.step(pc_if);
+                let if_id <- fetchModule32.step(pc_if);
                 dynamicAssert(if_id.common.pc == pc_if.pc, "Fetch - Memory request denied trap check - common.pc");
                 dynamicAssert(if_id.common.ir == defaultValue, "Fetch - Memory request denied trap check - common.ir");
-                dynamicAssert(!if_id.common.isBubble, "Fetch - Memory request denied trap check - common.isBubble");
                 dynamicAssert(isValid(if_id.common.trap), "Fetch - Memory request denied trap check - contains trap");
                 dynamicAssert(if_id.common.trap.Valid.cause == exception_INSTRUCTION_ACCESS_FAULT, "Memory request denied trap check - cause is access fault");
+                dynamicAssert(if_id.npc == 'h104, "Fetch - Misaligned instruction trap check - NPC incorrect");
+                dynamicAssert(if_id.epoch == defaultValue, "Fetch - Misaligned instruction trap check - Verify epoch unchanged");
             end
 
-            // Normal memory request (request submit)
+            // Normal memory request (step 1 - request submit)
             4: begin
                 pc_if.pc = 'h100;
 
                 // The fetch should proceed and return a bubble.
-                let if_id <- fetchStage32.step(pc_if);
+                let if_id <- fetchModule32.step(pc_if);
                 dynamicAssert(if_id == defaultValue, "Fetch - Normal request - request should return a bubble");
             end
 
-            // Normal memory request (request receipt)
+            // Normal memory request (step 2 - request receipt)
             5: begin
                 pc_if.pc = 'h100;
 
                 // Ensure the fetch returns a bubble while the memory request is in flight
-                let if_id <- fetchStage32.step(pc_if);
+                let if_id <- fetchModule32.step(pc_if);
                 dynamicAssert(if_id == defaultValue, "Fetch - Normal request - request should return a bubble while fetch is in flight");
 
                 dynamicAssert(memoryRequests32.notEmpty, "Fetch - Normal request - memory request queue should not be empty");
@@ -105,26 +106,69 @@ module mkTopModule(Empty);
                 memoryRequests32.deq;
 
                 dynamicAssert(memoryRequest.address == 'h100, "Fetch - Normal request - memory request should have correct address");
-                fetchStage32.memoryClient.response.put(ReadOnlyMemoryResponse {
+                dynamicAssert(memoryRequest.byteen == 'b1111, "Fetch - Normal request - memory request byte enable should be 'b1111");
+                fetchModule32.memoryClient.response.put(FallibleMemoryResponse {
                     data: 'haabb_ccdd,
                     accessFault: False
                 });
             end
 
-            // Normal memory request (return value check)
+            // Normal memory request (step 3 - return value check)
             6: begin
                 pc_if.pc = 'h100;
 
-                // The fetch should proceed and return a bubble.
-                let if_id <- fetchStage32.step(pc_if);
+                let if_id <- fetchModule32.step(pc_if);
                 dynamicAssert(if_id.common.pc == pc_if.pc, "Fetch - Normal request - common.pc");
-                dynamicAssert(!if_id.common.isBubble, "Fetch - Normal request - common.isBubble");
                 dynamicAssert(!isValid(if_id.common.trap), "Fetch - Normal request - contains no trap");
                 dynamicAssert(if_id.common.ir.value == 'haabb_ccdd, "Fetch - Normal request - contains expected instruction data");
+                dynamicAssert(if_id.npc == 'h104, "Fetch - Normal request - NPC incorrect");
+                dynamicAssert(if_id.epoch == defaultValue, "Fetch - Normal request - Verify epoch unchanged");
+            end
+
+            // Redirect handling check (step 1 - request submit)
+            7: begin
+                pc_if.pc = 'h100;
+                pc_if.redirection = tagged Valid 'h8000;
+
+                // The fetch should proceed and return a bubble.
+                let if_id <- fetchModule32.step(pc_if);
+                dynamicAssert(if_id == defaultValue, "Fetch - Redirect check - request should return a bubble");
+            end
+
+            // Redirect handling check (step 2 - request receipt)
+            8: begin
+                pc_if.pc = 'h100;
+
+                // Ensure the fetch returns a bubble while the memory request is in flight
+                let if_id <- fetchModule32.step(pc_if);
+                dynamicAssert(if_id == defaultValue, "Fetch - Redirect check - request should return a bubble while fetch is in flight");
+
+                dynamicAssert(memoryRequests32.notEmpty, "Fetch - Redirect check - memory request queue should not be empty");
+                let memoryRequest = memoryRequests32.first;
+                memoryRequests32.deq;
+
+                dynamicAssert(memoryRequest.address == 'h8000, "Fetch - Redirect check - memory request should have correct address");
+                dynamicAssert(memoryRequest.byteen == 'b1111, "Fetch - Redirect check - memory request byte enable should be 'b1111");
+                fetchModule32.memoryClient.response.put(FallibleMemoryResponse {
+                    data: 'haabb_ccee,
+                    accessFault: False
+                });
+            end
+
+            // Redirect handling check (step 3 - return value check)
+            9: begin
+                pc_if.pc = 'h100;
+
+                let if_id <- fetchModule32.step(pc_if);
+                dynamicAssert(if_id.common.pc == 'h8000, "Fetch - Redirect check - common.pc");
+                dynamicAssert(!isValid(if_id.common.trap), "Fetch - Redirect check - contains no trap");
+                dynamicAssert(if_id.common.ir.value == 'haabb_ccee, "Fetch - Redirect check - contains expected instruction data");
+                dynamicAssert(if_id.npc == 'h8004, "Fetch - Redirect check - NPC incorrect");
+                dynamicAssert(if_id.epoch == 'h1, "Fetch - Redirect check - Verify epoch changed");
             end
 
             default: begin
-                dynamicAssert(stepNumber == 7, "Fetch - not all tests run");
+                dynamicAssert(stepNumber == 10, "Fetch - not all tests run");
                 $display(">>>PASS");
                 $finish();
             end

src/Cpu/GprFile.bsv

@@ -1,18 +1,18 @@
+import RV_ISA::*;
+
 import ClientServer::*;
 import GetPut::*;
 import Vector::*;
 
-typedef Bit#(5) GprIndex;
-
 interface GprReadPort#(numeric type xlen);
-    method Bit#(xlen) read(GprIndex index);
+    method Bit#(xlen) read(RVGPRIndex index);
 endinterface
 
 interface GprWritePort#(numeric type xlen);
-    method Action write(GprIndex index, Bit#(xlen) value);
+    method Action write(RVGPRIndex index, Bit#(xlen) value);
 endinterface
 
-interface GprFile#(numeric type xlen);
+interface GprFileIfc#(numeric type xlen);
     interface GprReadPort#(xlen) gprReadPort1;
     interface GprReadPort#(xlen) gprReadPort2;
 
@@ -22,23 +22,23 @@ endinterface
 typedef struct {
 } GprFileCfg#(numeric type xlen);
 
-module mkGprFile#(GprFileCfg#(xlen) cfg)(GprFile#(xlen));
+module mkGprFile#(GprFileCfg#(xlen) cfg)(GprFileIfc#(xlen));
     Vector#(32, Reg#(Bit#(xlen))) reg_file <- replicateM(mkReg(0));
 
     interface GprReadPort gprReadPort1;
-        method Bit#(xlen) read(GprIndex index);
+        method Bit#(xlen) read(RVGPRIndex index);
             return reg_file[index];
         endmethod
     endinterface
 
     interface GprReadPort gprReadPort2;
-        method Bit#(xlen) read(GprIndex index);
+        method Bit#(xlen) read(RVGPRIndex index);
             return reg_file[index];
         endmethod
     endinterface
 
     interface GprWritePort gprWritePort;
-        method Action write(GprIndex index, Bit#(xlen) value);
+        method Action write(RVGPRIndex index, Bit#(xlen) value);
             if (index != 0) begin
                 reg_file[index] <= value;
             end

src/Cpu/MemoryAccessStage.bsv

@@ -9,18 +9,18 @@ import FIFOF::*;
 import GetPut::*;
 import Memory::*;
 
-interface MemoryAccessStage_Ifc#(numeric type xlen);
+interface MemoryAccessModuleIfc#(numeric type xlen);
     method ActionValue#(MEM_WB#(xlen)) step(EX_MEM#(xlen) ex_mem);
     interface MemoryClient#(xlen, xlen) memoryClient;
 endinterface
 
-module mkMemoryAccessStage#(IsaCfg#(xlen) cfg)(MemoryAccessStage_Ifc#(xlen));
+module mkMemoryAccessModule#(IsaCfg#(xlen) cfg)(MemoryAccessModuleIfc#(xlen));
     // Memory request output
     Reg#(Bool) memoryRequestInFlight <- mkReg(False);
     Wire#(MemoryRequest#(xlen, xlen)) memoryRequest <- mkWire;
 
     // Memory response input (FIFO)
-    // Note: This is an unguarded FIFO so status much be checked before attempting to enq() and deq().
+    // Note: This is an unguarded FIFO so status must be checked before attempting to enq() and deq().
     FIFOF#(MemoryResponse#(xlen)) memoryResponses <- mkUGFIFOF1;
 
     //
@@ -29,8 +29,17 @@ module mkMemoryAccessStage#(IsaCfg#(xlen) cfg)(MemoryAccessStage_Ifc#(xlen));
     //
     method ActionValue#(MEM_WB#(xlen)) step(EX_MEM#(xlen) ex_mem);
         MEM_WB#(xlen) mem_wb = defaultValue;
-        if (!ex_mem.common.isBubble) begin
-        end
+
+        case (mem_wb.common.ir.value[6:0])
+            matches 7'b0?00011: begin
+                // LOAD/STORE
+                
+            end
+            default: begin
+                // All other opcodes
+                mem_wb.common = ex_mem.common;
+            end
+        endcase
         
         return mem_wb;
     endmethod
@@ -45,3 +54,32 @@ module mkMemoryAccessStage#(IsaCfg#(xlen) cfg)(MemoryAccessStage_Ifc#(xlen));
         endinterface
     endinterface
 endmodule
+
+interface MemoryAccessStageIfc#(numeric type xlen);
+    interface Put#(EX_MEM#(xlen)) put;
+    interface Get#(MEM_WB#(xlen)) get;
+endinterface
+
+module mkMemoryAccessStage#(IsaCfg#(xlen) cfg)(MemoryAccessStageIfc#(xlen));
+    //
+    // State
+    //
+    Wire#(EX_MEM#(xlen)) ex_mem <- mkWire;
+    Reg#(MEM_WB#(xlen))  mem_wb <- mkRegU;
+    MemoryAccessModuleIfc#(xlen) memoryAccessModule <- mkMemoryAccessModule(cfg);
+
+    //
+    // Rules
+    //
+    (* no_implicit_conditions *)
+    rule step;
+        let mem_wb_ <- memoryAccessModule.step(ex_mem);
+        mem_wb <= mem_wb_;
+    endrule
+
+    //
+    // Interfaces
+    //
+    interface Put put = toPut(asIfc(ex_mem));
+    interface Get get = toGet(mem_wb);
+endmodule

src/Cpu/MemoryAccessStage_tb.bsv

@@ -20,11 +20,11 @@ module mkTopModule(Empty);
         extS: False,
         extU: False
     };
-    MemoryAccessStage_Ifc#(32) memoryAccessStage32 <- mkMemoryAccessStage(rv32);
+    MemoryAccessModuleIfc#(32) memoryAccessModule32 <- mkMemoryAccessModule(rv32);
 
     FIFOF#(MemoryRequest#(32, 32)) memoryRequests32 <- mkUGFIFOF1();
 
-    mkConnection(memoryAccessStage32.memoryClient.request, toPut(asIfc(memoryRequests32)));
+    mkConnection(memoryAccessModule32.memoryClient.request, toPut(asIfc(memoryRequests32)));
 
     (* no_implicit_conditions *)
     rule test;
@@ -33,7 +33,7 @@ module mkTopModule(Empty);
         case(testNumber)
             // Simple bubble passthrough
             0: begin
-                let mem_wb <- memoryAccessStage32.step(ex_mem);
+                let mem_wb <- memoryAccessModule32.step(ex_mem);
                 dynamicAssert(mem_wb == defaultValue, "MemoryAccess - Bubble passthrough check");
             end
 

src/Cpu/PipelineRegisters.bsv

@@ -1,6 +1,12 @@
+import CsrFile::*;
 import Trap::*;
 import DefaultValue::*;
 
+//
+// Epoch
+//
+typedef Bit#(1) Epoch;
+
 //
 // Instruction
 //
@@ -25,12 +31,14 @@ typedef Bit#(xlen) ProgramCounter#(numeric type xlen);
 typedef struct {
     ProgramCounter#(xlen) pc;
     Maybe#(ProgramCounter#(xlen)) redirection;
+    Epoch epoch;
 } PC_IF#(numeric type xlen) deriving(Bits, Eq, FShow);
 
-instance DefaultValue #(PC_IF#(xlen));
+instance DefaultValue#(PC_IF#(xlen));
     defaultValue = PC_IF { 
         pc: 'h-1,
-        redirection: tagged Invalid
+        redirection: tagged Invalid,
+        epoch: defaultValue
     };
 endinstance
 
@@ -40,7 +48,6 @@ endinstance
 typedef struct {
     Instruction             ir;
     ProgramCounter#(xlen)   pc;
-    Bool                    isBubble;
     Maybe#(Trap#(xlen))     trap;
 } PipelineRegisterCommon#(numeric type xlen) deriving(Bits, Eq, FShow);
 
@@ -48,7 +55,6 @@ instance DefaultValue #(PipelineRegisterCommon#(xlen));
     defaultValue = PipelineRegisterCommon { 
         ir:         defaultValue,
         pc:         defaultValue,
-        isBubble:   True,
         trap:       tagged Invalid
     };
 endinstance
@@ -58,14 +64,14 @@ endinstance
 //
 typedef struct {
     PipelineRegisterCommon#(xlen) common;
-    Bit#(1)                       epoch;
+    Epoch                         epoch;
     ProgramCounter#(xlen)         npc;     // Next program counter
 } IF_ID#(numeric type xlen) deriving(Bits, Eq, FShow);
 
 instance DefaultValue #(IF_ID#(xlen));
     defaultValue = IF_ID {
         common: defaultValue,
-        epoch:  'h-1,
+        epoch:  defaultValue,
         npc:    defaultValue
     };
 endinstance
@@ -75,23 +81,26 @@ endinstance
 //
 typedef struct {
     PipelineRegisterCommon#(xlen) common;
-    Bit#(1)                       epoch;
-    ProgramCounter#(xlen)         npc;         // Next program counter
-    Bit#(xlen)                    a;           // Operand 1
-    Bit#(xlen)                    b;           // Operand 2
-    Bool                          isBValid;    // In the case of a CSR, this will indicate if 'b' is valid 
-    Bit#(xlen)                    imm;         // Sign extended immediate
+    Epoch                         epoch;
+    ProgramCounter#(xlen)         npc;          // Next program counter
+    Bit#(xlen)                    a;            // Operand 1
+    Bit#(xlen)                    b;            // Operand 2
+    Bit#(xlen)                    imm;          // Sign extended immediate
+    CsrReadResult#(xlen)          csr;          // CSR read result
 } ID_EX#(numeric type xlen) deriving(Bits, Eq, FShow);
 
 instance DefaultValue #(ID_EX#(xlen));
     defaultValue = ID_EX {
         common:   defaultValue,
-        epoch:    0,
+        epoch:    defaultValue,
         npc:      defaultValue,
         a:        'h-1,
         b:        'h-1,
-        isBValid: True,
-        imm:      'h-1
+        imm:      'h-1,
+        csr:      CsrReadResult {
+            value: 'h-1,
+            denied: False
+        }
     };
 endinstance
 

src/Cpu/RV_ISA.bsv

@@ -43,102 +43,102 @@ RVBranchOperator branch_BLTU            = 3'b110;
 RVBranchOperator branch_BGEU            = 3'b111;
 
 //
-// RVCsrIndex
+// RVCSRIndex
 //
-typedef Bit#(12) RVCsrIndex;
+typedef Bit#(12) RVCSRIndex;
 // Supervisor Trap Setup
-RVCsrIndex csr_SSTATUS         = 12'h100;    // Supervisor Status Register (SRW)
-RVCsrIndex csr_SIE             = 12'h104;    // Supervisor Interrupt Enable Register (SRW)
-RVCsrIndex csr_STVEC           = 12'h105;    // Supervisor Trap-Handler base address (SRW)
-RVCsrIndex csr_SCOUNTEREN      = 12'h106;    // Supervisor Counter Enable Register (SRW)
+RVCSRIndex csr_SSTATUS         = 12'h100;    // Supervisor Status Register (SRW)
+RVCSRIndex csr_SIE             = 12'h104;    // Supervisor Interrupt Enable Register (SRW)
+RVCSRIndex csr_STVEC           = 12'h105;    // Supervisor Trap-Handler base address (SRW)
+RVCSRIndex csr_SCOUNTEREN      = 12'h106;    // Supervisor Counter Enable Register (SRW)
 // Supervisor Configuration
-RVCsrIndex csr_SENVCFG         = 12'h10A;    // Supervisor environment configuration register (SRW)
+RVCSRIndex csr_SENVCFG         = 12'h10A;    // Supervisor environment configuration register (SRW)
 // Supervisor Trap Handling
-RVCsrIndex csr_SSCRATCH        = 12'h140;    // Scratch register for supervisor trap handlers (SRW)
-RVCsrIndex csr_SEPC            = 12'h141;    // Supervisor exception program counter (SRW)
-RVCsrIndex csr_SCAUSE          = 12'h142;    // Supervisor trap cause (SRW)
-RVCsrIndex csr_STVAL           = 12'h143;    // Supervisor bad address or instruction (SRW)
-RVCsrIndex csr_SIP             = 12'h144;    // Supervisor interrupt pending (SRW)
+RVCSRIndex csr_SSCRATCH        = 12'h140;    // Scratch register for supervisor trap handlers (SRW)
+RVCSRIndex csr_SEPC            = 12'h141;    // Supervisor exception program counter (SRW)
+RVCSRIndex csr_SCAUSE          = 12'h142;    // Supervisor trap cause (SRW)
+RVCSRIndex csr_STVAL           = 12'h143;    // Supervisor bad address or instruction (SRW)
+RVCSRIndex csr_SIP             = 12'h144;    // Supervisor interrupt pending (SRW)
 // Supervisor Protection and Translation
-RVCsrIndex csr_SATP            = 12'h180;    // Supervisor address translation and protection (SRW)
+RVCSRIndex csr_SATP            = 12'h180;    // Supervisor address translation and protection (SRW)
 // Machine Trap Setup
-RVCsrIndex csr_MSTATUS         = 12'h300;    // Machine Status Register (MRW)
-RVCsrIndex csr_MISA            = 12'h301;    // Machine ISA and Extensions Register (MRW)
-RVCsrIndex csr_MEDELEG         = 12'h302;    // Machine Exception Delegation Register (MRW)
-RVCsrIndex csr_MIDELEG         = 12'h303;    // Machine Interrupt Delegation Register (MRW)
-RVCsrIndex csr_MIE             = 12'h304;    // Machine Interrupt Enable Register (MRW)
-RVCsrIndex csr_MTVEC           = 12'h305;    // Machine Trap-Handler base address (MRW)
-RVCsrIndex csr_MCOUNTEREN      = 12'h306;    // Machine Counter Enable Register (MRW)
-RVCsrIndex csr_MSTATUSH        = 12'h310;    // Additional machine status register, RV32 only (MRW)
+RVCSRIndex csr_MSTATUS         = 12'h300;    // Machine Status Register (MRW)
+RVCSRIndex csr_MISA            = 12'h301;    // Machine ISA and Extensions Register (MRW)
+RVCSRIndex csr_MEDELEG         = 12'h302;    // Machine Exception Delegation Register (MRW)
+RVCSRIndex csr_MIDELEG         = 12'h303;    // Machine Interrupt Delegation Register (MRW)
+RVCSRIndex csr_MIE             = 12'h304;    // Machine Interrupt Enable Register (MRW)
+RVCSRIndex csr_MTVEC           = 12'h305;    // Machine Trap-Handler base address (MRW)
+RVCSRIndex csr_MCOUNTEREN      = 12'h306;    // Machine Counter Enable Register (MRW)
+RVCSRIndex csr_MSTATUSH        = 12'h310;    // Additional machine status register, RV32 only (MRW)
 
 // Machine Trap Handling
-RVCsrIndex csr_MSCRATCH        = 12'h340;    // Scratch register for machine trap handlers (MRW)
-RVCsrIndex csr_MEPC            = 12'h341;    // Machine exception program counter (MRW)
-RVCsrIndex csr_MCAUSE          = 12'h342;    // Machine trap cause (MRW)
-RVCsrIndex csr_MTVAL           = 12'h343;    // Machine bad address or instruction (MRW)
-RVCsrIndex csr_MIP             = 12'h344;    // Machine interrupt pending (MRW)
-RVCsrIndex csr_MTINST          = 12'h34A;    // Machine trap instruction (transformed) (MRW)
-RVCsrIndex csr_MTVAL2          = 12'h34B;    // Machine bad guest physical address (MRW)
+RVCSRIndex csr_MSCRATCH        = 12'h340;    // Scratch register for machine trap handlers (MRW)
+RVCSRIndex csr_MEPC            = 12'h341;    // Machine exception program counter (MRW)
+RVCSRIndex csr_MCAUSE          = 12'h342;    // Machine trap cause (MRW)
+RVCSRIndex csr_MTVAL           = 12'h343;    // Machine bad address or instruction (MRW)
+RVCSRIndex csr_MIP             = 12'h344;    // Machine interrupt pending (MRW)
+RVCSRIndex csr_MTINST          = 12'h34A;    // Machine trap instruction (transformed) (MRW)
+RVCSRIndex csr_MTVAL2          = 12'h34B;    // Machine bad guest physical address (MRW)
 // Machine Memory Protection
-RVCsrIndex csr_PMPCFG0         = 12'h3A0;    // Physical memory protection configuration (MRW)
-RVCsrIndex csr_PMPCFG15        = 12'h3AF; 
-RVCsrIndex csr_PMPADDR0        = 12'h3B0;    // Physical memory protection address register (MRW)
-RVCsrIndex csr_PMPADDR63       = 12'h3EF;
+RVCSRIndex csr_PMPCFG0         = 12'h3A0;    // Physical memory protection configuration (MRW)
+RVCSRIndex csr_PMPCFG15        = 12'h3AF; 
+RVCSRIndex csr_PMPADDR0        = 12'h3B0;    // Physical memory protection address register (MRW)
+RVCSRIndex csr_PMPADDR63       = 12'h3EF;
 // Debug/Trace Registers
-RVCsrIndex csr_TSELECT         = 12'h7A0;    // Debug/Trace trigger register select (MRW)
-RVCsrIndex csr_TDATA1          = 12'h7A1;    // First Debug/Trace trigger data register (MRW)
-RVCsrIndex csr_TDATA2          = 12'h7A2;    // Second Debug/Trace trigger data register (MRW)
-RVCsrIndex csr_TDATA3          = 12'h7A3;    // Third Debug/Trace trigger data register (MRW)
-RVCsrIndex csr_MCONTEXT        = 12'h7A8;    // Machine-mode context register (MRW)
+RVCSRIndex csr_TSELECT         = 12'h7A0;    // Debug/Trace trigger register select (MRW)
+RVCSRIndex csr_TDATA1          = 12'h7A1;    // First Debug/Trace trigger data register (MRW)
+RVCSRIndex csr_TDATA2          = 12'h7A2;    // Second Debug/Trace trigger data register (MRW)
+RVCSRIndex csr_TDATA3          = 12'h7A3;    // Third Debug/Trace trigger data register (MRW)
+RVCSRIndex csr_MCONTEXT        = 12'h7A8;    // Machine-mode context register (MRW)
 // Debug Mode Registers
-RVCsrIndex csr_DCSR            = 12'h7B0;    // Debug Control and Status
-RVCsrIndex csr_DPC             = 12'h7B1;    // Debug Program Counter
-RVCsrIndex csr_DSCRATCH0       = 12'h7B2;    // Debug Scratch Register 0
-RVCsrIndex csr_DSCRATCH1       = 12'h7B3;    // Debug Scratch Register 1
+RVCSRIndex csr_DCSR            = 12'h7B0;    // Debug Control and Status
+RVCSRIndex csr_DPC             = 12'h7B1;    // Debug Program Counter
+RVCSRIndex csr_DSCRATCH0       = 12'h7B2;    // Debug Scratch Register 0
+RVCSRIndex csr_DSCRATCH1       = 12'h7B3;    // Debug Scratch Register 1
 // Machine Counters/Timers
-RVCsrIndex csr_MCYCLE          = 12'hB00;    // Cycle counter for RDCYCLE instruction (MRW)
-RVCsrIndex csr_MINSTRET        = 12'hB02;    // Machine instructions-retired counter (MRW)
-RVCsrIndex csr_MHPMCOUNTER3    = 12'hB03;    // Machine performance-monitoring counter (MRW)
-RVCsrIndex csr_MHPMCOUNTER4    = 12'hB04;    // Machine performance-monitoring counter (MRW)
-RVCsrIndex csr_MHPMCOUNTER5    = 12'hB05;    // Machine performance-monitoring counter (MRW)
-RVCsrIndex csr_MHPMCOUNTER6    = 12'hB06;    // Machine performance-monitoring counter (MRW)
-RVCsrIndex csr_MHPMCOUNTER7    = 12'hB07;    // Machine performance-monitoring counter (MRW)
-RVCsrIndex csr_MHPMCOUNTER8    = 12'hB08;    // Machine performance-monitoring counter (MRW)
-RVCsrIndex csr_MHPMCOUNTER9    = 12'hB09;    // Machine performance-monitoring counter (MRW)
-RVCsrIndex csr_MCYCLEH         = 12'hB80;    // Upper 32 bits of mcycle, RV32I only (MRW)
-RVCsrIndex csr_MINSTRETH       = 12'hB82;    // Upper 32 bits of minstret, RV32I only (MRW)    
-RVCsrIndex csr_MHPMCOUNTER3H   = 12'hB83;    // Machine performance-monitoring counter (upper 32 bits) (MRW)
-RVCsrIndex csr_MHPMCOUNTER4H   = 12'hB84;    // Machine performance-monitoring counter (upper 32 bits) (MRW)
-RVCsrIndex csr_MHPMCOUNTER5H   = 12'hB85;    // Machine performance-monitoring counter (upper 32 bits) (MRW)
-RVCsrIndex csr_MHPMCOUNTER6H   = 12'hB86;    // Machine performance-monitoring counter (upper 32 bits) (MRW)
-RVCsrIndex csr_MHPMCOUNTER7H   = 12'hB87;    // Machine performance-monitoring counter (upper 32 bits) (MRW)
-RVCsrIndex csr_MHPMCOUNTER8H   = 12'hB88;    // Machine performance-monitoring counter (upper 32 bits) (MRW)
-RVCsrIndex csr_MHPMCOUNTER9H   = 12'hB89;    // Machine performance-monitoring counter (upper 32 bits) (MRW)
-RVCsrIndex csr_CYCLE           = 12'hC00;    // Read only mirror of MCYCLE
+RVCSRIndex csr_MCYCLE          = 12'hB00;    // Cycle counter for RDCYCLE instruction (MRW)
+RVCSRIndex csr_MINSTRET        = 12'hB02;    // Machine instructions-retired counter (MRW)
+RVCSRIndex csr_MHPMCOUNTER3    = 12'hB03;    // Machine performance-monitoring counter (MRW)
+RVCSRIndex csr_MHPMCOUNTER4    = 12'hB04;    // Machine performance-monitoring counter (MRW)
+RVCSRIndex csr_MHPMCOUNTER5    = 12'hB05;    // Machine performance-monitoring counter (MRW)
+RVCSRIndex csr_MHPMCOUNTER6    = 12'hB06;    // Machine performance-monitoring counter (MRW)
+RVCSRIndex csr_MHPMCOUNTER7    = 12'hB07;    // Machine performance-monitoring counter (MRW)
+RVCSRIndex csr_MHPMCOUNTER8    = 12'hB08;    // Machine performance-monitoring counter (MRW)
+RVCSRIndex csr_MHPMCOUNTER9    = 12'hB09;    // Machine performance-monitoring counter (MRW)
+RVCSRIndex csr_MCYCLEH         = 12'hB80;    // Upper 32 bits of mcycle, RV32I only (MRW)
+RVCSRIndex csr_MINSTRETH       = 12'hB82;    // Upper 32 bits of minstret, RV32I only (MRW)    
+RVCSRIndex csr_MHPMCOUNTER3H   = 12'hB83;    // Machine performance-monitoring counter (upper 32 bits) (MRW)
+RVCSRIndex csr_MHPMCOUNTER4H   = 12'hB84;    // Machine performance-monitoring counter (upper 32 bits) (MRW)
+RVCSRIndex csr_MHPMCOUNTER5H   = 12'hB85;    // Machine performance-monitoring counter (upper 32 bits) (MRW)
+RVCSRIndex csr_MHPMCOUNTER6H   = 12'hB86;    // Machine performance-monitoring counter (upper 32 bits) (MRW)
+RVCSRIndex csr_MHPMCOUNTER7H   = 12'hB87;    // Machine performance-monitoring counter (upper 32 bits) (MRW)
+RVCSRIndex csr_MHPMCOUNTER8H   = 12'hB88;    // Machine performance-monitoring counter (upper 32 bits) (MRW)
+RVCSRIndex csr_MHPMCOUNTER9H   = 12'hB89;    // Machine performance-monitoring counter (upper 32 bits) (MRW)
+RVCSRIndex csr_CYCLE           = 12'hC00;    // Read only mirror of MCYCLE
 // Machine Information Registers
-RVCsrIndex csr_MVENDORID       = 12'hF11;    // Vendor ID (MRO)
-RVCsrIndex csr_MARCHID         = 12'hF12;    // Architecture ID (MRO)
-RVCsrIndex csr_MIMPID          = 12'hF13;    // Implementation ID (MRO)
-RVCsrIndex csr_MHARTID         = 12'hF14;    // Hardware thread ID (MRO)
-RVCsrIndex csr_MCONFIGPTR      = 12'hF15;    // Pointer to configuration data structure (MRO)
+RVCSRIndex csr_MVENDORID       = 12'hF11;    // Vendor ID (MRO)
+RVCSRIndex csr_MARCHID         = 12'hF12;    // Architecture ID (MRO)
+RVCSRIndex csr_MIMPID          = 12'hF13;    // Implementation ID (MRO)
+RVCSRIndex csr_MHARTID         = 12'hF14;    // Hardware thread ID (MRO)
+RVCSRIndex csr_MCONFIGPTR      = 12'hF15;    // Pointer to configuration data structure (MRO)
 
 //
-// RVCsrIndexOffset
+// RVCSRIndexOffset
 //
-typedef Bit#(8) RVCsrIndexOffset;
+typedef Bit#(8) RVCSRIndexOffset;
 // Trap Setup
-RVCsrIndexOffset csr_STATUS    = 8'h00;      // Status
-RVCsrIndexOffset csr_EDELEG    = 8'h02;      // Exception Delegation
-RVCsrIndexOffset csr_IDELEG    = 8'h03;      // Interrupt Delegation
-RVCsrIndexOffset csr_IE        = 8'h04;      // Interrupt Enable
-RVCsrIndexOffset csr_TVEC      = 8'h05;      // Vector Table
-RVCsrIndexOffset csr_COUNTEREN = 8'h06;      // Counter Enable
+RVCSRIndexOffset csr_STATUS    = 8'h00;      // Status
+RVCSRIndexOffset csr_EDELEG    = 8'h02;      // Exception Delegation
+RVCSRIndexOffset csr_IDELEG    = 8'h03;      // Interrupt Delegation
+RVCSRIndexOffset csr_IE        = 8'h04;      // Interrupt Enable
+RVCSRIndexOffset csr_TVEC      = 8'h05;      // Vector Table
+RVCSRIndexOffset csr_COUNTEREN = 8'h06;      // Counter Enable
 // Trap Handling
-RVCsrIndexOffset csr_SCRATCH   = 8'h40;      // Scratch Register
-RVCsrIndexOffset csr_EPC       = 8'h41;      // Exception Program Counter
-RVCsrIndexOffset csr_CAUSE     = 8'h42;      // Exception/Interrupt Cause
-RVCsrIndexOffset csr_TVAL      = 8'h43;      // Bad address or instruction
-RVCsrIndexOffset csr_IP        = 8'h44;      // Interrupt Pending
+RVCSRIndexOffset csr_SCRATCH   = 8'h40;      // Scratch Register
+RVCSRIndexOffset csr_EPC       = 8'h41;      // Exception Program Counter
+RVCSRIndexOffset csr_CAUSE     = 8'h42;      // Exception/Interrupt Cause
+RVCSRIndexOffset csr_TVAL      = 8'h43;      // Bad address or instruction
+RVCSRIndexOffset csr_IP        = 8'h44;      // Interrupt Pending
 
 //
 // RVCSROperator(s)

src/Cpu/Trap.bsv

@@ -4,7 +4,7 @@ typedef struct {
     Bit#(xlen) tval;
 } Trap#(numeric type xlen) deriving(Bits, Eq, FShow);
 
-interface TrapController#(numeric type xlen);
+interface TrapControllerIfc#(numeric type xlen);
     method ActionValue#(Bit#(xlen)) beginTrap(Bit#(xlen) trap_program_counter, Trap#(xlen) trap);
     method ActionValue#(Bit#(xlen)) endTrap;
 endinterface

src/ESeries.bsv

@@ -4,7 +4,7 @@
 import Soc::*;
 
 //!topmodule mkE001
-module mkE001(SocIfc#(32, 32));
+module mkE001(Soc#(32, 32));
     SocCfg#(32, 32) cfg = SocCfg {
         cpu_cfg: CpuCfg {
             initial_program_counter: 'h8000_0000
@@ -14,11 +14,11 @@ module mkE001(SocIfc#(32, 32));
 endmodule
 
 //!topmodule mkE003
-module mkE003(SocIfc#(64, 32));
+module mkE003(Soc#(64, 32));
     SocCfg#(64, 32) cfg = SocCfg{
         cpu_cfg: CpuCfg {
             initial_program_counter: 'h8000_0000
         }
     };
     let soc <- mkSoc(cfg);
-endmodule
+endmodule

src/Memory/MemoryIO.bsv

@@ -0,0 +1,25 @@
+import ClientServer::*;
+import GetPut::*;
+import Memory::*;
+
+typedef struct {
+    Bit#(dataSz) data;
+    Bool accessFault;   // The memory request faulted
+} FallibleMemoryResponse#(numeric type dataSz) deriving(Bits, Eq, FShow);
+
+//
+// ReadWriteMemory
+//
+typedef Client#(MemoryRequest#(addrSz, dataSz), FallibleMemoryResponse#(dataSz)) ReadWriteMemoryClient#(numeric type addrSz, numeric type dataSz);
+typedef Server#(MemoryRequest#(addrSz, dataSz), FallibleMemoryResponse#(dataSz)) ReadWriteMemoryServer#(numeric type addrSz, numeric type dataSz);
+
+//
+// ReadOnlyMemory
+//
+typedef struct {
+    Bit#(TDiv#(dataSz,8)) byteen;
+    Bit#(addrSz) address;
+} ReadOnlyMemoryRequest#(numeric type addrSz, numeric type dataSz) deriving(Bits, Eq, FShow);
+
+typedef Client#(ReadOnlyMemoryRequest#(addrSz, dataSz), FallibleMemoryResponse#(dataSz)) ReadOnlyMemoryClient#(numeric type addrSz, numeric type dataSz);
+typedef Server#(ReadOnlyMemoryRequest#(addrSz, dataSz), FallibleMemoryResponse#(dataSz)) ReadOnlyMemoryServer#(numeric type addrSz, numeric type dataSz);

src/Memory/MemoryTypes.bsv

@@ -1,13 +0,0 @@
-import ClientServer::*;
-
-typedef struct {
-    Bit#(a) address;
-} ReadOnlyMemoryRequest#(numeric type a) deriving(Bits, Eq);
-
-typedef struct {
-    Bit#(d) data;
-    Bool accessFault;
-} ReadOnlyMemoryResponse#(numeric type d) deriving(Bits, Eq);
-
-typedef Client#(ReadOnlyMemoryRequest#(a), ReadOnlyMemoryResponse#(d))
-                ReadOnlyMemoryClient#(numeric type a, numeric type d);

src/Soc.bsv

@@ -1,5 +1,5 @@
 import Cpu::*;
-export CpuCfg(..), mkSoc, SocCfg(..), SocIfc(..);
+export CpuCfg(..), mkSoc, SocCfg(..), Soc(..);
 
 //
 // SocConfig
@@ -9,14 +9,14 @@ typedef struct {
 } SocCfg#(numeric type xlen, numeric type ifetchByteCount);
 
 //
-// SocIfc
+// Soc
 //
-interface SocIfc#(numeric type xlen, numeric type ifetchByteCount);
+interface Soc#(numeric type xlen, numeric type ifetchByteCount);
 endinterface
 
 //
 // mkSoc()
 //
-module mkSoc#(SocCfg#(xlen, ifetchByteCount) cfg)(SocIfc#(xlen, ifetchByteCount));
+module mkSoc#(SocCfg#(xlen, ifetchByteCount) cfg)(Soc#(xlen, ifetchByteCount));
     let cpu <- mkCpu(cfg.cpu_cfg);
 endmodule