turn off 2 word store durring non-fp instructions

pipelined/src/fpu/fctrl.sv

@@ -41,7 +41,7 @@ module fctrl (
   input  logic [2:0] FRM_REGW,  // rounding mode from CSR
   input  logic [1:0] STATUS_FS, // is FPU enabled?
   input  logic       FDivBusyE,  // is the divider busy
-  output logic       IllegalFPUInstrD, // Is the instruction an illegal fpu instruction
+  output logic       IllegalFPUInstrD, IllegalFPUInstrM, // Is the instruction an illegal fpu instruction
   output logic 		         FRegWriteM, FRegWriteW, // FP register write enable
   output logic [2:0] 	      FrmM,                   // FP rounding mode
   output logic [`FMTBITS-1:0] FmtE, FmtM,             // FP format
@@ -55,6 +55,7 @@ module fctrl (
 
   `define FCTRLW 11
   logic [`FCTRLW-1:0] ControlsD;
+  logic       IllegalFPUInstrE;
   logic 		  FRegWriteD; // FP register write enable
   logic 		  DivStartD; // integer register write enable
   logic 		  FWriteIntD; // integer register write enable
@@ -171,6 +172,25 @@ module fctrl (
     else if (`FPSIZES == 3|`FPSIZES == 4)
       assign FmtD = ((Funct7D[6:3] == 4'b0100)&OpD[4]) ? Rs2D[1:0] : Funct7D[1:0];
 
+      
+//     // signals to help readability
+//     assign IntToFp = OpCtrl[2];
+//     assign CvtOp = (PostProcSelE == 2'b00)&(FResSelE == 2'b01);
+//     assign FmaOp = (PostProcSelE == 2'b10)&(FResSelE == 2'b01);
+//     assign Sqrt =  OpCtrl[0];
+
+//     // is there an input of infinity or NaN being used
+//     assign InfIn = (XInf&~(IntToFp&CvtOp))|(YInf&~CvtOp)|(ZInf&FmaOp);
+//     assign NaNIn = (XNaN&~(IntToFp&CvtOp))|(YNaN&~CvtOp)|(ZNaN&FmaOp);
+
+// // enables:
+// //    X - all except int->fp, store, load, mv int->fp
+// //    Y - all except cvt, mv, load, class
+// //    Z - fma ops only
+//     assign XEnE = ;
+//     assign YEnE = ~((FResSel==2'b10));
+//     assign ZEnE = FmaOp&~OpCtrlE[2];
+
 //  Final Res Sel:
 //        fp      int
 //  00  other     cmp
@@ -228,10 +248,14 @@ module fctrl (
    flopenrc #(15) DEAdrReg(clk, reset, FlushE, ~StallE, {InstrD[19:15], InstrD[24:20], InstrD[31:27]}, 
                            {Adr1E, Adr2E, Adr3E});
   flopenrc #(1) DEDivStartReg(clk, reset, FlushE, ~StallE|FDivBusyE, DivStartD, DivStartE);
+  if(`FLEN>`XLEN)
+    flopenrc #(1) DEIllegalReg(clk, reset, FlushE, ~StallE, IllegalFPUInstrD, IllegalFPUInstrE);
   // E/M pipleine register
   flopenrc #(12+int'(`FMTBITS)) EMCtrlReg (clk, reset, FlushM, ~StallM,
               {FRegWriteE, FResSelE, PostProcSelE, FrmE, FmtE, OpCtrlE, FWriteIntE},
               {FRegWriteM, FResSelM, PostProcSelM, FrmM, FmtM, OpCtrlM, FWriteIntM});
+  if(`FLEN>`XLEN)
+    flopenrc #(1) EMIllegalReg(clk, reset, FlushM, ~StallM, IllegalFPUInstrE, IllegalFPUInstrM);
   // M/W pipleine register
   flopenrc #(3)  MWCtrlReg(clk, reset, FlushW, ~StallW,
           {FRegWriteM, FResSelM},

pipelined/src/fpu/fpu.sv

@@ -72,6 +72,7 @@ module fpu (
    logic [1:0] 	      FResSelE, FResSelM;       // Select one of the results that finish in the memory stage
    logic [1:0] 	      PostProcSelE, PostProcSelM; // select result in the post processing unit
    logic [4:0] 	      Adr1E, Adr2E, Adr3E;                // adresses of each input
+   logic                IllegalFPUInstrM;
 
    // regfile signals
    logic [`FLEN-1:0] FRD1D, FRD2D, FRD3D;                // Read Data from FP register - decode stage
@@ -163,7 +164,7 @@ module fpu (
    fctrl fctrl (.Funct7D(InstrD[31:25]), .OpD(InstrD[6:0]), .Rs2D(InstrD[24:20]), .Funct3D(InstrD[14:12]), .InstrD,
                .StallE, .StallM, .StallW, .FlushE, .FlushM, .FlushW, .FRM_REGW, .STATUS_FS, .FDivBusyE,
                .reset, .clk, .IllegalFPUInstrD, .FRegWriteM, .FRegWriteW, .FrmM, .FmtE, .FmtM,
-               .DivStartE, .FWriteIntE, .FWriteIntM, .OpCtrlE, .OpCtrlM,
+               .DivStartE, .FWriteIntE, .FWriteIntM, .OpCtrlE, .OpCtrlM, .IllegalFPUInstrM,
                .FResSelE, .FResSelM, .FResSelW, .PostProcSelE, .PostProcSelM, .Adr1E, .Adr2E, .Adr3E);
 
    // FP register file
@@ -290,8 +291,8 @@ module fpu (
       assign FWriteDataE = YE[`XLEN-1:0]; 
    end else begin
       logic [`FLEN-1:0] FWriteDataE;
-      if(`FMTBITS == 2) assign FStore2 = FmtM == `FMT;
-      else assign FStore2 = FmtM;
+      if(`FMTBITS == 2) assign FStore2 = (FmtM == `FMT)&~IllegalFPUInstrM;
+      else assign FStore2 = FmtM&~IllegalFPUInstrM;
 
       if (`FPSIZES==1) assign FWriteDataE = YE;
       else if (`FPSIZES==2) assign FWriteDataE = FmtE ? YE : {2{YE[`LEN1-1:0]}};

pipelined/src/fpu/unpackinput.sv

@@ -30,6 +30,7 @@
 
 module unpackinput ( 
     input logic  [`FLEN-1:0]        In,    // inputs from register file
+    // input logic                     En,     // enable the input
     input logic  [`FMTBITS-1:0]     Fmt,       // format signal 00 - single 01 - double 11 - quad 10 - half
     output logic                    Sgn,    // sign bits of XYZ
     output logic [`NE-1:0]          Exp,    // exponents of XYZ (converted to largest supported precision)