Implement multiplication decode

1 files changed, 34 insertions, 0 deletions

diff --git a/rtl/core/decode/mul.sv b/rtl/core/decode/mul.sv
new file mode 100644
index 0000000..f67435c
--- /dev/null
+++ b/rtl/core/decode/mul.sv
@@ -0,0 +1,34 @@
+`include "core/decode/isa.sv"
+`include "core/uarch.sv"
+
+module core_decode_mul
+(
+	input  word       insn,
+
+	output mul_decode decode,
+	output reg_num    rd,
+	                  rs,
+	                  rm,
+	output logic      update_flags
+);
+
+	logic long_mul;
+	reg_num short_rd, rn;
+
+	assign rd = long_mul ? rn : short_rd;
+	assign rs = insn `FIELD_MUL_RS;
+	assign rm = insn `FIELD_MUL_RM;
+	assign update_flags = insn `FIELD_MUL_S;
+
+	assign decode.enable = 0;
+	assign decode.add = insn `FIELD_MUL_ACC;
+	assign decode.long_mul = long_mul;
+	assign decode.signed_mul = insn `FIELD_MUL_SIGNED;
+	assign decode.r_add_lo = long_mul ? rn : short_rd;
+	assign decode.r_add_hi = short_rd;
+
+	assign long_mul = insn `FIELD_MUL_LONG;
+	assign short_rd = insn `FIELD_MUL_RD;
+	assign rn = insn `FIELD_MUL_RN;
+
+endmodule