2 files changed, 11 insertions, 3 deletions
diff --git a/techlibs/xilinx/cells_sim.v b/techlibs/xilinx/cells_sim.v
index fa9be2c33..d863b2ad7 100644
--- a/techlibs/xilinx/cells_sim.v
+++ b/techlibs/xilinx/cells_sim.v
@@ -126,7 +126,11 @@ endmodule
 //   assign O = IO, IO = T ? 1'bz : I;
 // endmodule
 
-module INV(output O, input I);
+module INV(
+    (* clkbuf_inv = "I" *)
+    output O,
+    input I
+);
   assign O = !I;
 endmodule
 
diff --git a/techlibs/xilinx/lut_map.v b/techlibs/xilinx/lut_map.v
index 13d3c3268..62d501632 100644
--- a/techlibs/xilinx/lut_map.v
+++ b/techlibs/xilinx/lut_map.v
@@ -56,8 +56,12 @@ module \$lut (A, Y);
 
   generate
     if (WIDTH == 1) begin
-      LUT1 #(.INIT(P_LUT)) _TECHMAP_REPLACE_ (.O(Y),
-        .I0(A[0]));
+      if (P_LUT == 2'b01) begin
+        INV _TECHMAP_REPLACE_ (.O(Y), .I(A[0]));
+      end else begin
+        LUT1 #(.INIT(P_LUT)) _TECHMAP_REPLACE_ (.O(Y),
+          .I0(A[0]));
+      end
     end else
     if (WIDTH == 2) begin
       LUT2 #(.INIT(P_LUT)) _TECHMAP_REPLACE_ (.O(Y),