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Update compressed decoder to RVC 1.9

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Sven Stucki 2015-10-27 12:39:59 +01:00
parent ad57e4effa
commit bdb70cd4cc
1 changed files with 23 additions and 19 deletions
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42
compressed_decoder.sv
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@ -44,7 +44,7 @@ module riscv_compressed_decoder
always_comb
begin
illegal_instr_o = 1'b0;
instr_o = 'X;
instr_o = 'x;
unique case (instr_i[1:0])
// C0
@ -126,30 +126,34 @@ module riscv_compressed_decoder
2'b11: begin
unique case ({instr_i[12], instr_i[6:5]})
3'b001,
3'b000: begin
// c.sub -> sub rd', rd', rs2'
instr_o = {2'b01, 5'b0, 2'b01, instr_i[4:2], 2'b01, instr_i[9:7], 3'b000, 2'b01, instr_i[9:7], `OPCODE_OP};
end
3'b001: begin
// c.xor -> xor rd', rd', rs2'
instr_o = {7'b0, 2'b01, instr_i[4:2], 2'b01, instr_i[9:7], 3'b100, 2'b01, instr_i[9:7], `OPCODE_OP};
end
3'b010: begin
// c.or -> or rd', rd', rs2'
instr_o = {7'b0, 2'b01, instr_i[4:2], 2'b01, instr_i[9:7], 3'b110, 2'b01, instr_i[9:7], `OPCODE_OP};
end
3'b011: begin
// c.and -> and rd', rd', rs2'
instr_o = {7'b0, 2'b01, instr_i[4:2], 2'b01, instr_i[9:7], 3'b111, 2'b01, instr_i[9:7], `OPCODE_OP};
end
3'b100,
3'b101,
3'b110,
3'b111: begin
// 001: c.sll -> sll rd', rd', rs2'
// 100: c.xor -> xor rd', rd', rs2'
// 101: c.srl -> srl rd', rd', rs2'
// 110: c.or -> or rd', rd', rs2'
// 111: c.and -> and rd', rd', rs2'
instr_o = {7'b0, 2'b01, instr_i[4:2], 2'b01, instr_i[9:7], instr_i[12], instr_i[6:5], 2'b01, instr_i[9:7], `OPCODE_OP};
end
3'b000,
3'b010: begin
// 000: c.addw
// 010: c.subw
// 100: c.subw
// 101: c.addw
illegal_instr_o = 1'b1;
end
3'b011: begin
// c.sub -> sub rd', rd', rs2'
instr_o = {2'b01, 5'b0, 2'b01, instr_i[4:2], 2'b01, instr_i[9:7], 3'b000, 2'b01, instr_i[9:7], `OPCODE_OP};
end
endcase
end
endcase