From 3eff2271d0fe25632f7e6b22cf0be078d2cd9990 Mon Sep 17 00:00:00 2001
From: Pepijn de Vos <pepijndevos@gmail.com>
Date: Thu, 5 Sep 2019 13:36:41 +0200
Subject: [PATCH] add MUX support
---
techlibs/gowin/cells_map.v | 3 +++
techlibs/gowin/cells_sim.v | 13 +++++++++++++
techlibs/gowin/synth_gowin.cc | 1 +
3 files changed, 17 insertions(+)
diff --git a/techlibs/gowin/cells_map.v b/techlibs/gowin/cells_map.v
index ebdc88a0a..c38805b91 100644
--- a/techlibs/gowin/cells_map.v
+++ b/techlibs/gowin/cells_map.v
@@ -5,6 +5,9 @@ module \$__DFFS_PN0_ (input D, C, R, output Q); DFFR _TECHMAP_REPLACE_ (.D(D),
module \$__DFFS_PP0_ (input D, C, R, output Q); DFFR _TECHMAP_REPLACE_ (.D(D), .Q(Q), .CLK(C), .RESET(R)); endmodule
module \$__DFFS_PP1_ (input D, C, R, output Q); DFFR _TECHMAP_REPLACE_ (.D(D), .Q(Q), .CLK(C), .RESET(R)); endmodule
+module \$_MUX_ (input A, B, S, output Y); MUX2 _TECHMAP_REPLACE_ (.I0(A), .I1(B), .S0(S), .O(Y)); endmodule
+module \$_MUX4_ (input A, B, C, D, S, T, output Y); MUX4 _TECHMAP_REPLACE_ (.I0(A), .I1(B), .I2(C), .I3(D), .S0(S), .S1(T), .O(Y)); endmodule
+
module \$lut (A, Y);
parameter WIDTH = 0;
parameter LUT = 0;
diff --git a/techlibs/gowin/cells_sim.v b/techlibs/gowin/cells_sim.v
index ebb238bad..98dfef9bf 100644
--- a/techlibs/gowin/cells_sim.v
+++ b/techlibs/gowin/cells_sim.v
@@ -24,6 +24,19 @@ module LUT4(output F, input I0, I1, I2, I3);
assign F = I0 ? s1[1] : s1[0];
endmodule
+module MUX2 (I0, I1, S0, O);
+input I0, I1, S0;
+output O;
+assign O = S0 ? I1 : I0;
+endmodule
+
+module MUX4 (I0, I1, I2, I3, S0, S1, O);
+input I0, I1, I2, I3, S0, S1;
+output O;
+assign O = S1 ? (S0 ? I3 : I2) :
+ (S0 ? I1 : I0);
+endmodule
+
module DFF (output reg Q, input CLK, D);
parameter [0:0] INIT = 1'b0;
initial Q = INIT;
diff --git a/techlibs/gowin/synth_gowin.cc b/techlibs/gowin/synth_gowin.cc
index f7a5006bc..4d32f62d4 100644
--- a/techlibs/gowin/synth_gowin.cc
+++ b/techlibs/gowin/synth_gowin.cc
@@ -196,6 +196,7 @@ struct SynthGowinPass : public ScriptPass
run("opt_clean");
if (!nodffe)
run("dff2dffe -direct-match $_DFF_* -direct-match $__DFFS_*");
+ run("muxcover -mux4");
run("techmap -map +/gowin/cells_map.v");
run("opt_expr -mux_undef");
run("simplemap");