From e5535b9fe8e1899c6223e3082863914cc7b6386d Mon Sep 17 00:00:00 2001 From: Miodrag Milanovic Date: Mon, 22 Apr 2024 14:06:03 +0200 Subject: [PATCH] Made NX_CY model more robust --- techlibs/nanoxplore/cells_sim.v | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) diff --git a/techlibs/nanoxplore/cells_sim.v b/techlibs/nanoxplore/cells_sim.v index 9c3cace479a..3af9dd539a0 100644 --- a/techlibs/nanoxplore/cells_sim.v +++ b/techlibs/nanoxplore/cells_sim.v @@ -40,7 +40,15 @@ endmodule module NX_CY(input A1, A2, A3, A4, B1, B2, B3, B4, (* abc9_carry *) input CI, output S1, S2, S3, S4, (* abc9_carry *) output CO); parameter add_carry = 0; -assign {CO, S4, S3, S2, S1} = {A4, A3, A2, A1} + {B4, B3, B2, B1} + CI; +wire CI_1; +wire CO1, CO2, CO3; + +assign CI_1 = (add_carry==2) ? CI : ((add_carry==1) ? 1'b1 : 1'b0); + +assign { CO1, S1 } = A1 + B1 + CI_1; +assign { CO2, S2 } = A2 + B2 + CO1; +assign { CO3, S3 } = A3 + B3 + CO2; +assign { CO, S4 } = A4 + B4 + CO3; endmodule