Merge pull request #673 from daveshah1/ecp5_improve

Small ECP5 improvements

techlibs/ecp5/Makefile.inc

@@ -8,6 +8,7 @@ $(eval $(call add_share_file,share/ecp5,techlibs/ecp5/dram.txt))
 $(eval $(call add_share_file,share/ecp5,techlibs/ecp5/brams_map.v))
 $(eval $(call add_share_file,share/ecp5,techlibs/ecp5/bram.txt))
 $(eval $(call add_share_file,share/ecp5,techlibs/ecp5/arith_map.v))
+$(eval $(call add_share_file,share/ecp5,techlibs/ecp5/latches_map.v))
 
 EXTRA_OBJS += techlibs/ecp5/brams_init.mk techlibs/ecp5/brams_connect.mk
 .SECONDARY: techlibs/ecp5/brams_init.mk techlibs/ecp5/brams_connect.mk

techlibs/ecp5/cells_sim.v

@@ -265,16 +265,18 @@ module TRELLIS_IO(
 	output O
 );
 	parameter DIR = "INPUT";
+	reg T_pd;
+	always @(*) if (T === 1'bz) T_pd <= 1'b0; else T_pd <= T;
 
 	generate
 		if (DIR == "INPUT") begin
 			assign B = 1'bz;
 			assign O = B;
 		end else if (DIR == "OUTPUT") begin
-			assign B = T ? 1'bz : I;
+			assign B = T_pd ? 1'bz : I;
 			assign O = 1'bx;
-		end else if (DIR == "INOUT") begin
-			assign B = T ? 1'bz : I;
+		end else if (DIR == "BIDIR") begin
+			assign B = T_pd ? 1'bz : I;
 			assign O = B;
 		end else begin
 			ERROR_UNKNOWN_IO_MODE error();

techlibs/ecp5/latches_map.v

@@ -0,0 +1,11 @@
+module \$_DLATCH_N_ (E, D, Q);
+  wire [1023:0] _TECHMAP_DO_ = "simplemap; opt";
+  input E, D;
+  output Q = !E ? D : Q;
+endmodule
+
+module \$_DLATCH_P_ (E, D, Q);
+  wire [1023:0] _TECHMAP_DO_ = "simplemap; opt";
+  input E, D;
+  output Q = E ? D : Q;
+endmodule

techlibs/ecp5/synth_ecp5.cc

@@ -266,10 +266,7 @@ struct SynthEcp5Pass : public ScriptPass
 			if (abc2 || help_mode) {
 				run("abc", "      (only if -abc2)");
 			}
-			//TODO
-#if 0
 			run("techmap -map +/ecp5/latches_map.v");
-#endif
 			if (nomux)
 				run("abc -lut 4");
 			else