From ca5a25cfbdbefada9dfb94a097b65e69226f3f9a Mon Sep 17 00:00:00 2001 From: Flavian Kaufmann Date: Wed, 1 May 2024 16:08:53 +0200 Subject: fixed alu bugs --- src/arithmetic_unit.v | 9 ++++----- 1 file changed, 4 insertions(+), 5 deletions(-) (limited to 'src/arithmetic_unit.v') diff --git a/src/arithmetic_unit.v b/src/arithmetic_unit.v index be087a7..64ec0f9 100644 --- a/src/arithmetic_unit.v +++ b/src/arithmetic_unit.v @@ -3,21 +3,20 @@ module arithmetic_unit #( )( input [N-1:0] A, B, input [1:0] OP, // 00: ADD, 01: SUB, 11: SLT - output [N-1:0] RESULT, - output OVERFLOW + output [N-1:0] RESULT ); wire [N-1:0] b, sum; -wire cin, altb; +wire cin, altb, overflow; assign b = OP[0] ? ~B : B; assign cin = OP[0]; assign sum = A + b + cin; -assign OVERFLOW = ~(A[N-1] ^ B[N-1] ^ OP[0]) & (A[N-1] ^ sum[N-1]); +assign overflow = ~(A[N-1] ^ B[N-1] ^ OP[0]) & (A[N-1] ^ sum[N-1]); -assign altb = OVERFLOW ^ sum[N-1]; +assign altb = overflow ^ sum[N-1]; assign RESULT = OP[1] ? {{(N-1){1'b0}}, altb} : sum; -- cgit v1.2.3