2 files changed, 28 insertions, 0 deletions
diff --git a/techlibs/common/simlib.v b/techlibs/common/simlib.v
index 465efc0a..c170945e 100644
--- a/techlibs/common/simlib.v
+++ b/techlibs/common/simlib.v
@@ -443,6 +443,22 @@ endmodule
 
 // --------------------------------------------------------
 
+module \$fa (A, B, C, X, Y);
+
+parameter WIDTH = 1;
+
+input [WIDTH-1:0] A, B, C;
+output [WIDTH-1:0] X, Y;
+
+wire [WIDTH-1:0] t1, t2, t3;
+
+assign t1 = A ^ B, t2 = A & B, t3 = C & t1;
+assign Y = t1 ^ C, X = t2 | t3;
+
+endmodule
+
+// --------------------------------------------------------
+
 module \$alu (A, B, CI, BI, X, Y, CO);
 
 parameter A_SIGNED = 0;
diff --git a/techlibs/common/techmap.v b/techlibs/common/techmap.v
index dc52ca5f..05074637 100644
--- a/techlibs/common/techmap.v
+++ b/techlibs/common/techmap.v
@@ -246,6 +246,18 @@ endmodule
 // ALU Infrastructure
 // --------------------------------------------------------
 
+module \$fa (A, B, C, X, Y);
+	parameter WIDTH = 1;
+
+	input [WIDTH-1:0] A, B, C;
+	output [WIDTH-1:0] X, Y;
+
+	wire [WIDTH-1:0] t1, t2, t3;
+
+	assign t1 = A ^ B, t2 = A & B, t3 = C & t1;
+	assign Y = t1 ^ C, X = t2 | t3;
+endmodule
+
 module \$__alu_ripple (A, B, CI, X, Y, CO);
 	parameter WIDTH = 1;