From 978c60e75bddcec8444c9adf2b9091f0d8f6ea4d Mon Sep 17 00:00:00 2001
From: tangxifan <tangxifan@gmail.com>
Date: Sat, 30 Oct 2021 13:29:38 -0700
Subject: [PATCH] [Flow] Disable DFFE and SDFF in no-ff Yosys scripts

---
 .../misc/ys_tmpl_yosys_vpr_bram_dsp_flow.ys         | 13 +++++++------
 1 file changed, 7 insertions(+), 6 deletions(-)

diff --git a/openfpga_flow/misc/ys_tmpl_yosys_vpr_bram_dsp_flow.ys b/openfpga_flow/misc/ys_tmpl_yosys_vpr_bram_dsp_flow.ys
index ea67a5918..8ecfe2cf0 100644
--- a/openfpga_flow/misc/ys_tmpl_yosys_vpr_bram_dsp_flow.ys
+++ b/openfpga_flow/misc/ys_tmpl_yosys_vpr_bram_dsp_flow.ys
@@ -25,12 +25,12 @@ opt_clean
 # demote inout ports to input or output port
 # with follow-up optimizations to clean up AST
 deminout
-opt
+opt -nodffe -nosdff
 
 opt_expr
 opt_clean
 check
-opt
+opt -nodffe -nosdff
 wreduce -keepdc
 peepopt
 pmuxtree
@@ -58,10 +58,10 @@ chtype -set $mul t:$__soft_mul# Extract arithmetic functions
 techmap
 alumacc
 share
-opt
+opt -nodffe -nosdff
 fsm
 # Run a quick follow-up optimization to sweep out unused nets/signals
-opt -fast
+opt -fast -nodffe -nosdff
 # Optimize any memory cells by merging share-able ports and collecting all the ports belonging to memorcy cells  
 memory -nomap
 opt_clean
@@ -78,14 +78,15 @@ opt -undriven -fine
 #########################
 # Map flip-flops
 #########################
+dfflegalize -cell $_DFF_P_ 0
 techmap -map +/adff2dff.v
 opt_expr -mux_undef
 simplemap
 opt_expr
 opt_merge
-opt_dff
+opt_dff -nodffe -nosdff
 opt_clean
-opt
+opt -nodffe -nosdff
 
 #########################
 # Map LUTs