cvw/wally-pipelined/testbench/testbench-busybear.sv
2021-04-14 20:20:34 -04:00

634 lines
24 KiB
Systemverilog

`include "wally-config.vh"
module testbench_busybear();
logic clk, reset;
logic [31:0] GPIOPinsIn;
logic [31:0] GPIOPinsOut, GPIOPinsEn;
// instantiate device to be tested
logic [31:0] CheckInstrD;
logic [`AHBW-1:0] HRDATA;
logic [31:0] HADDR;
logic [`AHBW-1:0] HWDATA;
logic HWRITE;
logic [2:0] HSIZE;
logic [2:0] HBURST;
logic [3:0] HPROT;
logic [1:0] HTRANS;
logic HMASTLOCK;
logic HCLK, HRESETn;
logic [`AHBW-1:0] HRDATAEXT;
logic HREADYEXT, HRESPEXT;
logic UARTSout;
assign GPIOPinsIn = 0;
assign UARTSin = 1;
// instantiate processor and memories
wallypipelinedsoc dut(.*);
// initialize test
initial
begin
reset <= 1; # 22; reset <= 0;
end
// read pc trace file
integer data_file_PC, scan_file_PC;
initial begin
data_file_PC = $fopen("/courses/e190ax/busybear_boot_new/parsedPC.txt", "r");
if (data_file_PC == 0) begin
$display("file couldn't be opened");
$stop;
end
end
integer data_file_PCW, scan_file_PCW;
initial begin
data_file_PCW = $fopen("/courses/e190ax/busybear_boot_new/parsedPC.txt", "r");
if (data_file_PCW == 0) begin
$display("file couldn't be opened");
$stop;
end
end
// read register trace file
integer data_file_rf, scan_file_rf;
initial begin
data_file_rf = $fopen("/courses/e190ax/busybear_boot_new/parsedRegs.txt", "r");
if (data_file_rf == 0) begin
$display("file couldn't be opened");
$stop;
end
end
// read CSR trace file
integer data_file_csr, scan_file_csr;
initial begin
data_file_csr = $fopen("/courses/e190ax/busybear_boot_new/parsedCSRs.txt", "r");
if (data_file_csr == 0) begin
$display("file couldn't be opened");
$stop;
end
end
// read memreads trace file
integer data_file_memR, scan_file_memR;
initial begin
data_file_memR = $fopen("/courses/e190ax/busybear_boot_new/parsedMemRead.txt", "r");
if (data_file_memR == 0) begin
$display("file couldn't be opened");
$stop;
end
end
// read memwrite trace file
integer data_file_memW, scan_file_memW;
initial begin
data_file_memW = $fopen("/courses/e190ax/busybear_boot_new/parsedMemWrite.txt", "r");
if (data_file_memW == 0) begin
$display("file couldn't be opened");
$stop;
end
end
// initial loading of memories
initial begin
$readmemh("/courses/e190ax/busybear_boot_new/bootmem.txt", dut.uncore.bootdtim.RAM, 'h1000 >> 3);
$readmemh("/courses/e190ax/busybear_boot_new/ram.txt", dut.uncore.dtim.RAM);
$readmemb(`TWO_BIT_PRELOAD, dut.hart.ifu.bpred.Predictor.DirPredictor.PHT.memory);
$readmemb(`BTB_PRELOAD, dut.hart.ifu.bpred.TargetPredictor.memory.memory);
end
integer warningCount = 0;
integer instrs;
//logic[63:0] adrTranslation[4:0];
//string translationType[4:0] = {"rf", "writeAdr", "PCW", "PC", "readAdr"};
//initial begin
// for(int i=0; i<5; i++) begin
// adrTranslation[i] = 64'b0;
// end
//end
//function logic equal(logic[63:0] adr, logic[63:0] adrExpected, integer func);
// if (adr[11:0] !== adrExpected[11:0]) begin
// equal = 1'b0;
// end else begin
// equal = 1'b1;
// if ((adr+adrTranslation[func]) !== adrExpected) begin
// adrTranslation[func] = adrExpected - adr;
// $display("warning: probably new address translation %x for %s at instr %0d", adrTranslation[func], translationType[func], instrs);
// warningCount += 1;
// end
// end
//endfunction
// pretty sure this isn't necessary anymore, but keeping this for now since its easier
function logic equal(logic[63:0] adr, logic[63:0] adrExpected, integer func);
equal = adr === adrExpected;
endfunction
`define ERROR \
#10; \
$display("processed %0d instructions with %0d warnings", instrs, warningCount); \
$stop;
logic [63:0] pcExpected;
logic [63:0] regExpected;
integer regNumExpected;
logic [`XLEN-1:0] PCW;
flopenr #(`XLEN) PCWReg(clk, reset, ~dut.hart.ieu.dp.StallW, dut.hart.ifu.PCM, PCW);
genvar i;
generate
for(i=1; i<32; i++) begin
always @(dut.hart.ieu.dp.regf.rf[i]) begin
if ($time == 0) begin
scan_file_rf = $fscanf(data_file_rf, "%x\n", regExpected);
if (dut.hart.ieu.dp.regf.rf[i] != regExpected) begin
$display("%0t ps, instr %0d: rf[%0d] does not equal rf expected: %x, %x", $time, instrs, i, dut.hart.ieu.dp.regf.rf[i], regExpected);
`ERROR
end
end else begin
scan_file_rf = $fscanf(data_file_rf, "%d\n", regNumExpected);
scan_file_rf = $fscanf(data_file_rf, "%x\n", regExpected);
if (i != regNumExpected) begin
$display("%0t ps, instr %0d: wrong register changed: %0d, %0d expected to switch to %x from %x", $time, instrs, i, regNumExpected, regExpected, dut.hart.ieu.dp.regf.rf[regNumExpected]);
`ERROR
end
if (~equal(dut.hart.ieu.dp.regf.rf[i],regExpected, 0)) begin
$display("%0t ps, instr %0d: rf[%0d] does not equal rf expected: %x, %x", $time, instrs, i, dut.hart.ieu.dp.regf.rf[i], regExpected);
`ERROR
end
//if (dut.hart.ieu.dp.regf.rf[i] !== regExpected) begin
// force dut.hart.ieu.dp.regf.rf[i] = regExpected;
// release dut.hart.ieu.dp.regf.rf[i];
//end
end
end
end
endgenerate
// RAM and bootram are addressed in 64-bit blocks - this logic handles R/W
// including subwords. Brief explanation on signals:
//
// readMask: bitmask of bits to read / write, left-shifted to align with
// nearest 64-bit boundary - examples
// HSIZE = 0 -> readMask = 11111111
// HSIZE = 1 -> readMask = 1111111111111111
//
// In the linux boot, the processor spends the first ~5 instructions in
// bootram, before jr jumps to main RAM
logic [63:0] readMask;
assign readMask = ((1 << (8*(1 << HSIZE))) - 1) << 8 * HADDR[2:0];
logic [`XLEN-1:0] readAdrExpected;
always @(dut.HRDATA) begin
#2;
if (dut.hart.MemRWM[1] && ~HWRITE && HADDR[31:3] != dut.PCF[31:3] && dut.HRDATA !== {64{1'bx}}) begin
//$display("%0t", $time);
if($feof(data_file_memR)) begin
$display("no more memR data to read");
`ERROR
end
scan_file_memR = $fscanf(data_file_memR, "%x\n", readAdrExpected);
scan_file_memR = $fscanf(data_file_memR, "%x\n", HRDATA);
if (~equal(HADDR,readAdrExpected,4)) begin
$display("%0t ps, instr %0d: HADDR does not equal readAdrExpected: %x, %x", $time, instrs, HADDR, readAdrExpected);
`ERROR
end
if ((readMask & HRDATA) !== (readMask & dut.HRDATA)) begin
if (HADDR inside `BUSYBEAR_FIX_READ) begin
//$display("warning %0t ps, instr %0d, adr %0d: forcing HRDATA to expected: %x, %x", $time, instrs, HADDR, HRDATA, dut.HRDATA);
force dut.uncore.HRDATA = HRDATA;
#9;
release dut.uncore.HRDATA;
warningCount += 1;
end else begin
$display("%0t ps, instr %0d: ExpectedHRDATA does not equal dut.HRDATA: %x, %x from address %x, %x", $time, instrs, HRDATA, dut.HRDATA, HADDR, HSIZE);
`ERROR
end
end
//end else if(dut.hart.MemRWM[1]) begin
// $display("%x, %x, %x, %t", HADDR, dut.PCF, dut.HRDATA, $time);
end
end
logic [`XLEN-1:0] writeDataExpected, writeAdrExpected;
// this might need to change
//always @(HWDATA or HADDR or HSIZE or HWRITE) begin
always @(negedge HWRITE) begin
//#1;
if ($time != 0) begin
if($feof(data_file_memW)) begin
$display("no more memW data to read");
`ERROR
end
scan_file_memW = $fscanf(data_file_memW, "%x\n", writeDataExpected);
scan_file_memW = $fscanf(data_file_memW, "%x\n", writeAdrExpected);
if (writeDataExpected != HWDATA) begin
$display("%0t ps, instr %0d: HWDATA does not equal writeDataExpected: %x, %x", $time, instrs, HWDATA, writeDataExpected);
`ERROR
end
if (~equal(writeAdrExpected,HADDR,1)) begin
$display("%0t ps, instr %0d: HADDR does not equal writeAdrExpected: %x, %x", $time, instrs, HADDR, writeAdrExpected);
`ERROR
end
end
end
integer totalCSR = 0;
logic [99:0] StartCSRexpected[63:0];
string StartCSRname[99:0];
initial begin
while(1) begin
scan_file_csr = $fscanf(data_file_csr, "%s\n", StartCSRname[totalCSR]);
if(StartCSRname[totalCSR] == "---") begin
break;
end
scan_file_csr = $fscanf(data_file_csr, "%x\n", StartCSRexpected[totalCSR]);
totalCSR = totalCSR + 1;
end
end
always @(dut.hart.priv.csr.genblk1.csrm.MCAUSE_REGW) begin
if (dut.hart.priv.csr.genblk1.csrm.MCAUSE_REGW == 2 && instrs > 1) begin
$display("!!!!!! illegal instruction !!!!!!!!!!");
$display("(as a reminder, MCAUSE and MEPC are set by this)");
$display("at %0t ps, instr %0d, HADDR %x", $time, instrs, HADDR);
`ERROR
end
if (dut.hart.priv.csr.genblk1.csrm.MCAUSE_REGW == 5 && instrs != 0) begin
$display("!!!!!! illegal (physical) memory access !!!!!!!!!!");
$display("(as a reminder, MCAUSE and MEPC are set by this)");
$display("at %0t ps, instr %0d, HADDR %x", $time, instrs, HADDR);
`ERROR
end
end
`define CHECK_CSR2(CSR, PATH) \
string CSR; \
logic [63:0] expected``CSR``; \
//CSR checking \
always @(``PATH``.``CSR``_REGW) begin \
if ($time > 1) begin \
if ("SEPC" == `"CSR`") begin #1; end \
if ("SCAUSE" == `"CSR`") begin #2; end \
if ("SSTATUS" == `"CSR`") begin #3; end \
scan_file_csr = $fscanf(data_file_csr, "%s\n", CSR); \
scan_file_csr = $fscanf(data_file_csr, "%x\n", expected``CSR``); \
if(CSR.icompare(`"CSR`")) begin \
$display("%0t ps, instr %0d: %s changed, expected %s", $time, instrs, `"CSR`", CSR); \
end \
if(``PATH``.``CSR``_REGW != ``expected``CSR) begin \
$display("%0t ps, instr %0d: %s does not equal %s expected: %x, %x", $time, instrs, `"CSR`", CSR, ``PATH``.``CSR``_REGW, ``expected``CSR); \
`ERROR \
end \
end else begin \
for(integer j=0; j<totalCSR; j++) begin \
if(!StartCSRname[j].icompare(`"CSR`")) begin \
if(``PATH``.``CSR``_REGW != StartCSRexpected[j]) begin \
$display("%0t ps, instr %0d: %s does not equal %s expected: %x, %x", $time, instrs, `"CSR`", StartCSRname[j], ``PATH``.``CSR``_REGW, StartCSRexpected[j]); \
`ERROR \
end \
end \
end \
end \
end
`define CHECK_CSR(CSR) \
`CHECK_CSR2(CSR, dut.hart.priv.csr)
`define CSRM dut.hart.priv.csr.genblk1.csrm
`define CSRS dut.hart.priv.csr.genblk1.csrs.genblk1
//`CHECK_CSR(FCSR)
`CHECK_CSR2(MCAUSE, `CSRM)
`CHECK_CSR(MCOUNTEREN)
`CHECK_CSR(MEDELEG)
`CHECK_CSR(MEPC)
//`CHECK_CSR(MHARTID)
`CHECK_CSR(MIDELEG)
`CHECK_CSR(MIE)
//`CHECK_CSR(MIP)
`CHECK_CSR2(MISA, `CSRM)
`CHECK_CSR2(MSCRATCH, `CSRM)
`CHECK_CSR(MSTATUS)
`CHECK_CSR2(MTVAL, `CSRM)
`CHECK_CSR(MTVEC)
//`CHECK_CSR2(PMPADDR0, `CSRM)
//`CHECK_CSR2(PMdut.PCFG0, `CSRM)
`CHECK_CSR(SATP)
`CHECK_CSR2(SCAUSE, `CSRS)
`CHECK_CSR(SCOUNTEREN)
`CHECK_CSR(SEPC)
`CHECK_CSR(SIE)
`CHECK_CSR2(SSCRATCH, `CSRS)
`CHECK_CSR(SSTATUS)
`CHECK_CSR2(STVAL, `CSRS)
`CHECK_CSR(STVEC)
//$stop;
initial begin
#34140421;
$stop;
end
initial begin //this is temporary until the bug can be fixed!!!
#11130100;
force dut.hart.ieu.dp.regf.rf[5] = 64'h0000000080000004;
#100;
release dut.hart.ieu.dp.regf.rf[5];
end
logic speculative;
initial begin
speculative = 0;
end
logic [63:0] lastCheckInstrD, lastPC, lastPC2;
string PCtextW, PCtext2W;
logic [31:0] InstrWExpected;
logic [63:0] PCWExpected;
always @(PCW or dut.hart.ieu.InstrValidW) begin
if(dut.hart.ieu.InstrValidW && PCW != 0) begin
if($feof(data_file_PCW)) begin
$display("no more PC data to read");
`ERROR
end
scan_file_PCW = $fscanf(data_file_PCW, "%s\n", PCtextW);
if (PCtextW != "ret" && PCtextW != "fence" && PCtextW != "nop" && PCtextW != "mret" && PCtextW != "sfence.vma" && PCtextW != "unimp") begin
scan_file_PC = $fscanf(data_file_PCW, "%s\n", PCtext2W);
PCtextW = {PCtextW, " ", PCtext2W};
end
scan_file_PCW = $fscanf(data_file_PCW, "%x\n", InstrWExpected);
// then expected PC value
scan_file_PCW = $fscanf(data_file_PCW, "%x\n", PCWExpected);
if(~equal(PCW,PCWExpected,2)) begin
$display("%0t ps, instr %0d: PCW does not equal PCW expected: %x, %x", $time, instrs, PCW, PCWExpected);
`ERROR
end
//if(it.InstrW != InstrWExpected) begin
// $display("%0t ps, instr %0d: InstrW does not equal InstrW expected: %x, %x", $time, instrs, it.InstrW, InstrWExpected);
//end
end
end
string PCtext, PCtext2;
initial begin
instrs = 0;
end
logic [31:0] InstrMask;
logic forcedInstr;
logic [63:0] lastPCD;
always @(dut.hart.ifu.PCD or dut.hart.ifu.InstrRawD or reset or negedge dut.hart.ifu.StallE) begin
if(~HWRITE) begin
#2;
if (~reset && dut.hart.ifu.InstrRawD[15:0] !== {16{1'bx}} && dut.hart.ifu.PCD !== 64'h0 && ~dut.hart.ifu.StallE) begin
if (dut.hart.ifu.PCD !== lastPCD) begin
lastCheckInstrD = CheckInstrD;
lastPC <= dut.hart.ifu.PCD;
lastPC2 <= lastPC;
if (speculative && (lastPC != pcExpected)) begin
speculative = ~equal(dut.hart.ifu.PCD,pcExpected,3);
if(dut.hart.ifu.PCD===pcExpected) begin
if(dut.hart.ifu.InstrRawD[6:0] == 7'b1010011) begin // for now, NOP out any float instrs
force CheckInstrD = 32'b0010011;
release CheckInstrD;
force dut.hart.ifu.InstrRawD = 32'b0010011;
#7;
release dut.hart.ifu.InstrRawD;
$display("warning: NOPing out %s at PC=%0x, instr %0d, time %0t", PCtext, dut.hart.ifu.PCD, instrs, $time);
warningCount += 1;
forcedInstr = 1;
end
else begin
forcedInstr = 0;
end
end
end
else begin
if($feof(data_file_PC)) begin
$display("no more PC data to read");
`ERROR
end
scan_file_PC = $fscanf(data_file_PC, "%s\n", PCtext);
if (PCtext != "ret" && PCtext != "fence" && PCtext != "nop" && PCtext != "mret" && PCtext != "sfence.vma" && PCtext != "unimp") begin
scan_file_PC = $fscanf(data_file_PC, "%s\n", PCtext2);
PCtext = {PCtext, " ", PCtext2};
end
scan_file_PC = $fscanf(data_file_PC, "%x\n", CheckInstrD);
if(dut.hart.ifu.PCD === pcExpected) begin
if(dut.hart.ifu.InstrRawD[6:0] == 7'b1010011) begin // for now, NOP out any float instrs
force CheckInstrD = 32'b0010011;
release CheckInstrD;
force dut.hart.ifu.InstrRawD = 32'b0010011;
#7;
release dut.hart.ifu.InstrRawD;
$display("warning: NOPing out %s at PC=%0x, instr %0d, time %0t", PCtext, dut.hart.ifu.PCD, instrs, $time);
warningCount += 1;
forcedInstr = 1;
end
else begin
forcedInstr = 0;
end
end
// then expected PC value
scan_file_PC = $fscanf(data_file_PC, "%x\n", pcExpected);
if (instrs <= 10 || (instrs <= 100 && instrs % 10 == 0) ||
(instrs <= 1000 && instrs % 100 == 0) || (instrs <= 10000 && instrs % 1000 == 0) ||
(instrs <= 100000 && instrs % 10000 == 0) || (instrs <= 1000000 && instrs % 100000 == 0)) begin
$display("loaded %0d instructions", instrs);
end
instrs += 1;
// are we at a branch/jump?
casex (lastCheckInstrD[31:0])
32'b00000000001000000000000001110011, // URET
32'b00010000001000000000000001110011, // SRET
32'b00110000001000000000000001110011, // MRET
32'bXXXXXXXXXXXXXXXXXXXXXXXXX1101111, // JAL
32'bXXXXXXXXXXXXXXXXXXXXXXXXX1100111, // JALR
32'bXXXXXXXXXXXXXXXXXXXXXXXXX1100011, // B
32'bXXXXXXXXXXXXXXXX110XXXXXXXXXXX01, // C.BEQZ
32'bXXXXXXXXXXXXXXXX111XXXXXXXXXXX01, // C.BNEZ
32'bXXXXXXXXXXXXXXXX101XXXXXXXXXXX01: // C.J
speculative = 1;
32'bXXXXXXXXXXXXXXXX1001000000000010, // C.EBREAK:
32'bXXXXXXXXXXXXXXXXX000XXXXX1110011: // Something that's not CSRR*
speculative = 0; // tbh don't really know what should happen here
32'b000110000000XXXXXXXXXXXXX1110011, // CSR* SATP, *
32'bXXXXXXXXXXXXXXXX1000XXXXX0000010, // C.JR
32'bXXXXXXXXXXXXXXXX1001XXXXX0000010: // C.JALR //this is RV64 only so no C.JAL
speculative = 1;
default:
speculative = 0;
endcase
//check things!
if ((~speculative) && (~equal(dut.hart.ifu.PCD,pcExpected,3))) begin
$display("%0t ps, instr %0d: PC does not equal PC expected: %x, %x", $time, instrs, dut.hart.ifu.PCD, pcExpected);
`ERROR
end
InstrMask = CheckInstrD[1:0] == 2'b11 ? 32'hFFFFFFFF : 32'h0000FFFF;
if ((~forcedInstr) && (~speculative) && ((InstrMask & dut.hart.ifu.InstrRawD) !== (InstrMask & CheckInstrD))) begin
$display("%0t ps, instr %0d: InstrD does not equal CheckInstrD: %x, %x, PC: %x", $time, instrs, dut.hart.ifu.InstrRawD, CheckInstrD, dut.hart.ifu.PCD);
`ERROR
end
end
end
lastPCD = dut.hart.ifu.PCD;
end
end
end
// Track names of instructions
string InstrFName, InstrDName, InstrEName, InstrMName, InstrWName;
logic [31:0] InstrW;
instrNameDecTB dec(dut.hart.ifu.ic.InstrF, InstrFName);
instrTrackerTB it(clk, reset, dut.hart.ieu.dp.FlushE,
dut.hart.ifu.InstrD, dut.hart.ifu.InstrE,
dut.hart.ifu.InstrM, InstrW,
InstrDName, InstrEName, InstrMName, InstrWName);
// generate clock to sequence tests
always
begin
clk <= 1; # 5; clk <= 0; # 5;
end
endmodule
module instrTrackerTB(
input logic clk, reset, FlushE,
input logic [31:0] InstrD,
input logic [31:0] InstrE, InstrM,
output logic [31:0] InstrW,
output string InstrDName, InstrEName, InstrMName, InstrWName);
// stage Instr to Writeback for visualization
//flopr #(32) InstrWReg(clk, reset, InstrM, InstrW);
instrNameDecTB ddec(InstrD, InstrDName);
instrNameDecTB edec(InstrE, InstrEName);
instrNameDecTB mdec(InstrM, InstrMName);
instrNameDecTB wdec(InstrW, InstrWName);
endmodule
// decode the instruction name, to help the test bench
module instrNameDecTB(
input logic [31:0] instr,
output string name);
logic [6:0] op;
logic [2:0] funct3;
logic [6:0] funct7;
logic [11:0] imm;
assign op = instr[6:0];
assign funct3 = instr[14:12];
assign funct7 = instr[31:25];
assign imm = instr[31:20];
// it would be nice to add the operands to the name
// create another variable called decoded
always_comb
casez({op, funct3})
10'b0000000_000: name = "BAD";
10'b0000011_000: name = "LB";
10'b0000011_001: name = "LH";
10'b0000011_010: name = "LW";
10'b0000011_011: name = "LD";
10'b0000011_100: name = "LBU";
10'b0000011_101: name = "LHU";
10'b0000011_110: name = "LWU";
10'b0010011_000: if (instr[31:15] == 0 && instr[11:7] ==0) name = "NOP/FLUSH";
else name = "ADDI";
10'b0010011_001: if (funct7[6:1] == 6'b000000) name = "SLLI";
else name = "ILLEGAL";
10'b0010011_010: name = "SLTI";
10'b0010011_011: name = "SLTIU";
10'b0010011_100: name = "XORI";
10'b0010011_101: if (funct7[6:1] == 6'b000000) name = "SRLI";
else if (funct7[6:1] == 6'b010000) name = "SRAI";
else name = "ILLEGAL";
10'b0010011_110: name = "ORI";
10'b0010011_111: name = "ANDI";
10'b0010111_???: name = "AUIPC";
10'b0100011_000: name = "SB";
10'b0100011_001: name = "SH";
10'b0100011_010: name = "SW";
10'b0100011_011: name = "SD";
10'b0011011_000: name = "ADDIW";
10'b0011011_001: name = "SLLIW";
10'b0011011_101: if (funct7 == 7'b0000000) name = "SRLIW";
else if (funct7 == 7'b0100000) name = "SRAIW";
else name = "ILLEGAL";
10'b0111011_000: if (funct7 == 7'b0000000) name = "ADDW";
else if (funct7 == 7'b0100000) name = "SUBW";
else name = "ILLEGAL";
10'b0111011_001: name = "SLLW";
10'b0111011_101: if (funct7 == 7'b0000000) name = "SRLW";
else if (funct7 == 7'b0100000) name = "SRAW";
else name = "ILLEGAL";
10'b0110011_000: if (funct7 == 7'b0000000) name = "ADD";
else if (funct7 == 7'b0000001) name = "MUL";
else if (funct7 == 7'b0100000) name = "SUB";
else name = "ILLEGAL";
10'b0110011_001: if (funct7 == 7'b0000000) name = "SLL";
else if (funct7 == 7'b0000001) name = "MULH";
else name = "ILLEGAL";
10'b0110011_010: if (funct7 == 7'b0000000) name = "SLT";
else if (funct7 == 7'b0000001) name = "MULHSU";
else name = "ILLEGAL";
10'b0110011_011: if (funct7 == 7'b0000000) name = "SLTU";
else if (funct7 == 7'b0000001) name = "DIV";
else name = "ILLEGAL";
10'b0110011_100: if (funct7 == 7'b0000000) name = "XOR";
else if (funct7 == 7'b0000001) name = "MUL";
else name = "ILLEGAL";
10'b0110011_101: if (funct7 == 7'b0000000) name = "SRL";
else if (funct7 == 7'b0000001) name = "DIVU";
else if (funct7 == 7'b0100000) name = "SRA";
else name = "ILLEGAL";
10'b0110011_110: if (funct7 == 7'b0000000) name = "OR";
else if (funct7 == 7'b0000001) name = "REM";
else name = "ILLEGAL";
10'b0110011_111: if (funct7 == 7'b0000000) name = "AND";
else if (funct7 == 7'b0000001) name = "REMU";
else name = "ILLEGAL";
10'b0110111_???: name = "LUI";
10'b1100011_000: name = "BEQ";
10'b1100011_001: name = "BNE";
10'b1100011_100: name = "BLT";
10'b1100011_101: name = "BGE";
10'b1100011_110: name = "BLTU";
10'b1100011_111: name = "BGEU";
10'b1100111_000: name = "JALR";
10'b1101111_???: name = "JAL";
10'b1110011_000: if (imm == 0) name = "ECALL";
else if (imm == 1) name = "EBREAK";
else if (imm == 2) name = "URET";
else if (imm == 258) name = "SRET";
else if (imm == 770) name = "MRET";
else name = "ILLEGAL";
10'b1110011_001: name = "CSRRW";
10'b1110011_010: name = "CSRRS";
10'b1110011_011: name = "CSRRC";
10'b1110011_101: name = "CSRRWI";
10'b1110011_110: name = "CSRRSI";
10'b1110011_111: name = "CSRRCI";
10'b0001111_???: name = "FENCE";
default: name = "ILLEGAL";
endcase
endmodule