Generic RISC-V ISS
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326 lines
12 KiB

InsructionSet RV32IBase {
constants {
XLEN,
PCLEN,
XLEN_BIT_MASK:=0x1f,
fence:=0,
fencei:=1,
fencevmal:=2,
fencevmau:=3
}
address_spaces {
MEM[8], CSR[XLEN], FENCE[XLEN]
}
registers {
[31:0] X[XLEN],
PC[XLEN](is_pc),
alias ZERO[XLEN] is X[0]
}
instructions {
LUI{
encoding: imm[31:12]s | rd[4:0] | b0110111;
args_disass: "x%rd$d, 0x%imm$05x";
if(rd!=0) X[rd] <= imm;
}
AUIPC{
encoding: imm[31:12]s | rd[4:0] | b0010111;
args_disass: "x%rd%, 0x%imm$08x";
if(rd!=0) X[rd] <= PC's+imm;
}
JAL(no_cont){
encoding: imm[20:20]s | imm[10:1]s | imm[11:11]s | imm[19:12]s | rd[4:0] | b1101111;
args_disass: "x%rd$d, 0x%imm$x";
if(rd!=0) X[rd] <= PC+4;
PC<=PC's+imm;
}
JALR(no_cont){
encoding: imm[11:0]s | rs1[4:0] | b000 | rd[4:0] | b1100111;
args_disass: "x%rd$d, x%rs1$d, 0x%imm$x";
val new_pc[XLEN] <= X[rs1]'s+ imm;
val align[XLEN] <= new_pc & 0x2;
if(align != 0){
raise(0, 0);
} else {
if(rd!=0) X[rd] <= PC+4;
PC<=new_pc & ~0x1;
}
}
BEQ(no_cont,cond){
encoding: imm[12:12]s |imm[10:5]s | rs2[4:0] | rs1[4:0] | b000 | imm[4:1]s | imm[11:11]s | b1100011;
args_disass:"x%rs1$d, x%rs2$d, 0x%imm$x";
PC<=choose(X[rs1]==X[rs2], PC's+imm, PC+4);
}
BNE(no_cont,cond){
encoding: imm[12:12]s |imm[10:5]s | rs2[4:0] | rs1[4:0] | b001 | imm[4:1]s | imm[11:11]s | b1100011;
args_disass:"x%rs1$d, x%rs2$d, 0x%imm$x";
PC<=choose(X[rs1]!=X[rs2], PC's+imm, PC+4);
}
BLT(no_cont,cond){
encoding: imm[12:12]s |imm[10:5]s | rs2[4:0] | rs1[4:0] | b100 | imm[4:1]s | imm[11:11]s | b1100011;
args_disass:"x%rs1$d, x%rs2$d, 0x%imm$x";
PC<=choose(X[rs1]s<X[rs2]s, PC's+imm, PC+4);
}
BGE(no_cont,cond) {
encoding: imm[12:12]s |imm[10:5]s | rs2[4:0] | rs1[4:0] | b101 | imm[4:1]s | imm[11:11]s | b1100011;
args_disass:"x%rs1$d, x%rs2$d, 0x%imm$x";
PC<=choose(X[rs1]s>=X[rs2]s, PC's+imm, PC+4);
}
BLTU(no_cont,cond) {
encoding: imm[12:12]s |imm[10:5]s | rs2[4:0] | rs1[4:0] | b110 | imm[4:1]s | imm[11:11]s | b1100011;
args_disass:"x%rs1$d, x%rs2$d, 0x%imm$x";
PC<=choose(X[rs1]<X[rs2],PC's+imm, PC+4);
}
BGEU(no_cont,cond) {
encoding: imm[12:12]s |imm[10:5]s | rs2[4:0] | rs1[4:0] | b111 | imm[4:1]s | imm[11:11]s | b1100011;
args_disass:"x%rs1$d, x%rs2$d, 0x%imm$x";
PC<=choose(X[rs1]>=X[rs2], PC's+imm, PC+4);
}
LB {
encoding: imm[11:0]s | rs1[4:0] | b000 | rd[4:0] | b0000011;
args_disass:"x%rd$d, %imm%(x%rs1$d)";
val offs[XLEN] <= X[rs1]'s+imm;
if(rd!=0) X[rd]<=sext(MEM[offs]);
}
LH {
encoding: imm[11:0]s | rs1[4:0] | b001 | rd[4:0] | b0000011;
args_disass:"x%rd$d, %imm%(x%rs1$d)";
val offs[XLEN] <= X[rs1]'s+imm;
if(rd!=0) X[rd]<=sext(MEM[offs]{16});
}
LW {
encoding: imm[11:0]s | rs1[4:0] | b010 | rd[4:0] | b0000011;
args_disass:"x%rd$d, %imm%(x%rs1$d)";
val offs[XLEN] <= X[rs1]'s+imm;
if(rd!=0) X[rd]<=sext(MEM[offs]{32});
}
LBU {
encoding: imm[11:0]s | rs1[4:0] | b100 | rd[4:0] | b0000011;
args_disass:"x%rd$d, %imm%(x%rs1$d)";
val offs[XLEN] <= X[rs1]'s+imm;
if(rd!=0) X[rd]<=zext(MEM[offs]);
}
LHU {
encoding: imm[11:0]s | rs1[4:0] | b101 | rd[4:0] | b0000011;
args_disass:"x%rd$d, %imm%(x%rs1$d)";
val offs[XLEN] <= X[rs1]'s+imm;
if(rd!=0) X[rd]<=zext(MEM[offs]{16});
}
SB {
encoding: imm[11:5]s | rs2[4:0] | rs1[4:0] | b000 | imm[4:0]s | b0100011;
args_disass:"x%rs2$d, %imm%(x%rs1$d)";
val offs[XLEN] <= X[rs1]'s + imm;
MEM[offs] <= X[rs2];
}
SH {
encoding: imm[11:5]s | rs2[4:0] | rs1[4:0] | b001 | imm[4:0]s | b0100011;
args_disass:"x%rs2$d, %imm%(x%rs1$d)";
val offs[XLEN] <= X[rs1]'s + imm;
MEM[offs]{16} <= X[rs2];
}
SW {
encoding: imm[11:5]s | rs2[4:0] | rs1[4:0] | b010 | imm[4:0]s | b0100011;
args_disass:"x%rs2$d, %imm%(x%rs1$d)";
val offs[XLEN] <= X[rs1]'s + imm;
MEM[offs]{32} <= X[rs2];
}
ADDI {
encoding: imm[11:0]s | rs1[4:0] | b000 | rd[4:0] | b0010011;
args_disass:"x%rd$d, x%rs1$d, %imm%";
if(rd != 0) X[rd] <= X[rs1]'s + imm;
}
SLTI {
encoding: imm[11:0]s | rs1[4:0] | b010 | rd[4:0] | b0010011;
args_disass:"x%rd$d, x%rs1$d, %imm%";
if (rd != 0) X[rd] <= choose(X[rs1]s < imm's, 1, 0);
}
SLTIU {
encoding: imm[11:0]s | rs1[4:0] | b011 | rd[4:0] | b0010011;
args_disass:"x%rd$d, x%rs1$d, %imm%";
val full_imm[XLEN] <= imm's;
if (rd != 0) X[rd] <= choose(X[rs1]'u < full_imm'u, 1, 0);
}
XORI {
encoding: imm[11:0] | rs1[4:0] | b100 | rd[4:0] | b0010011;
args_disass:"x%rd$d, x%rs1$d, %imm%";
if(rd != 0) X[rd] <= X[rs1] ^ imm;
}
ORI {
encoding: imm[11:0] | rs1[4:0] | b110 | rd[4:0] | b0010011;
args_disass:"x%rd$d, x%rs1$d, %imm%";
if(rd != 0) X[rd] <= X[rs1] | imm;
}
ANDI {
encoding: imm[11:0] | rs1[4:0] | b111 | rd[4:0] | b0010011;
args_disass:"x%rd$d, x%rs1$d, %imm%";
if(rd != 0) X[rd] <= X[rs1] & imm;
}
SLLI {
encoding: b0000000 | shamt[4:0] | rs1[4:0] | b001 | rd[4:0] | b0010011;
args_disass:"x%rd$d, x%rs1$d, %shamt%";
if(shamt > 31){
raise(0,0);
} else {
if(rd != 0) X[rd] <= shll(X[rs1], shamt);
}
}
SRLI {
encoding: b0000000 | shamt[4:0] | rs1[4:0] | b101 | rd[4:0] | b0010011;
args_disass:"x%rd$d, x%rs1$d, %shamt%";
if(shamt > 31){
raise(0,0);
} else {
if(rd != 0) X[rd] <= shrl(X[rs1], shamt);
}
}
SRAI {
encoding: b0100000 | shamt[4:0] | rs1[4:0] | b101 | rd[4:0] | b0010011;
args_disass:"x%rd$d, x%rs1$d, %shamt%";
if(shamt > 31){
raise(0,0);
} else {
if(rd != 0) X[rd] <= shra(X[rs1], shamt);
}
}
ADD {
encoding: b0000000 | rs2[4:0] | rs1[4:0] | b000 | rd[4:0] | b0110011;
args_disass:"x%rd$d, x%rs1$d, x%rs2$d";
if(rd != 0) X[rd] <= X[rs1] + X[rs2];
}
SUB {
encoding: b0100000 | rs2[4:0] | rs1[4:0] | b000 | rd[4:0] | b0110011;
args_disass:"x%rd$d, x%rs1$d, x%rs2$d";
if(rd != 0) X[rd] <= X[rs1] - X[rs2];
}
SLL {
encoding: b0000000 | rs2[4:0] | rs1[4:0] | b001 | rd[4:0] | b0110011;
args_disass:"x%rd$d, x%rs1$d, x%rs2$d";
if(rd != 0) X[rd] <= shll(X[rs1], X[rs2]&XLEN_BIT_MASK);
}
SLT {
encoding: b0000000 | rs2[4:0] | rs1[4:0] | b010 | rd[4:0] | b0110011;
args_disass:"x%rd$d, x%rs1$d, x%rs2$d";
if (rd != 0) X[rd] <= choose(X[rs1]s < X[rs2]s, 1, 0);
}
SLTU {
encoding: b0000000 | rs2[4:0] | rs1[4:0] | b011 | rd[4:0] | b0110011;
args_disass:"x%rd$d, x%rs1$d, x%rs2$d";
if (rd != 0) X[rd] <= choose(zext(X[rs1]) < zext(X[rs2]), 1, 0);
}
XOR {
encoding: b0000000 | rs2[4:0] | rs1[4:0] | b100 | rd[4:0] | b0110011;
args_disass:"x%rd$d, x%rs1$d, x%rs2$d";
if(rd != 0) X[rd] <= X[rs1] ^ X[rs2];
}
SRL {
encoding: b0000000 | rs2[4:0] | rs1[4:0] | b101 | rd[4:0] | b0110011;
args_disass:"x%rd$d, x%rs1$d, x%rs2$d";
if(rd != 0) X[rd] <= shrl(X[rs1], X[rs2]&XLEN_BIT_MASK);
}
SRA {
encoding: b0100000 | rs2[4:0] | rs1[4:0] | b101 | rd[4:0] | b0110011;
args_disass:"x%rd$d, x%rs1$d, x%rs2$d";
if(rd != 0) X[rd] <= shra(X[rs1], X[rs2]&XLEN_BIT_MASK);
}
OR {
encoding: b0000000 | rs2[4:0] | rs1[4:0] | b110 | rd[4:0] | b0110011;
args_disass:"x%rd$d, x%rs1$d, x%rs2$d";
if(rd != 0) X[rd] <= X[rs1] | X[rs2];
}
AND {
encoding: b0000000 | rs2[4:0] | rs1[4:0] | b111 | rd[4:0] | b0110011;
args_disass:"x%rd$d, x%rs1$d, x%rs2$d";
if(rd != 0) X[rd] <= X[rs1] & X[rs2];
}
FENCE {
encoding: b0000 | pred[3:0] | succ[3:0] | rs1[4:0] | b000 | rd[4:0] | b0001111;
FENCE[fence] <= pred<<4 | succ;
}
FENCE_I(flush) {
encoding: imm[11:0] | rs1[4:0] | b001 | rd[4:0] | b0001111 ;
FENCE[fencei] <= imm;
}
ECALL(no_cont) {
encoding: b000000000000 | b00000 | b000 | b00000 | b1110011;
raise(0, 11);
}
EBREAK(no_cont) {
encoding: b000000000001 | b00000 | b000 | b00000 | b1110011;
raise(0, 3);
}
URET(no_cont) {
encoding: b0000000 | b00010 | b00000 | b000 | b00000 | b1110011;
leave(0);
}
SRET(no_cont) {
encoding: b0001000 | b00010 | b00000 | b000 | b00000 | b1110011;
leave(1);
}
MRET(no_cont) {
encoding: b0011000 | b00010 | b00000 | b000 | b00000 | b1110011;
leave(3);
}
WFI {
encoding: b0001000 | b00101 | b00000 | b000 | b00000 | b1110011;
wait(1);
}
SFENCE.VMA {
encoding: b0001001 | rs2[4:0] | rs1[4:0] | b000 | b00000 | b1110011;
FENCE[fencevmal] <= rs1;
FENCE[fencevmau] <= rs2;
}
CSRRW {
encoding: csr[11:0] | rs1[4:0] | b001 | rd[4:0] | b1110011;
args_disass:"x%rd$d, %csr$d, x%rs1$d";
val rs_val[XLEN] <= X[rs1];
if(rd!=0){
val csr_val[XLEN] <= CSR[csr];
CSR[csr] <= rs_val;
// make sure Xrd is updated once CSR write succeeds
X[rd] <= csr_val;
} else {
CSR[csr] <= rs_val;
}
}
CSRRS {
encoding: csr[11:0] | rs1[4:0] | b010 | rd[4:0] | b1110011;
args_disass:"x%rd$d, %csr$d, x%rs1$d";
val xrd[XLEN] <= CSR[csr];
val xrs1[XLEN] <= X[rs1];
if(rd!=0) X[rd] <= xrd;
if(rs1!=0) CSR[csr] <= xrd | xrs1;
}
CSRRC {
encoding: csr[11:0] | rs1[4:0] | b011 | rd[4:0] | b1110011;
args_disass:"x%rd$d, %csr$d, x%rs1$d";
val xrd[XLEN] <= CSR[csr];
val xrs1[XLEN] <= X[rs1];
if(rd!=0) X[rd] <= xrd;
if(rs1!=0) CSR[csr] <= xrd & ~xrs1;
}
CSRRWI {
encoding: csr[11:0] | zimm[4:0] | b101 | rd[4:0] | b1110011;
args_disass:"x%rd$d, %csr$d, 0x%zimm$x";
if(rd!=0) X[rd] <= CSR[csr];
CSR[csr] <= zext(zimm);
}
CSRRSI {
encoding: csr[11:0] | zimm[4:0] | b110 | rd[4:0] | b1110011;
args_disass:"x%rd$d, %csr$d, 0x%zimm$x";
val res[XLEN] <= CSR[csr];
if(zimm!=0) CSR[csr] <= res | zext(zimm);
// make sure rd is written after csr write succeeds
if(rd!=0) X[rd] <= res;
}
CSRRCI {
encoding: csr[11:0] | zimm[4:0] | b111 | rd[4:0] | b1110011;
args_disass:"x%rd$d, %csr$d, 0x%zimm$x";
val res[XLEN] <= CSR[csr];
if(rd!=0) X[rd] <= res;
if(zimm!=0) CSR[csr] <= res & ~zext(zimm, XLEN);
}
}
}