machxo2: Initial support for carry chains (CCU2D)

4 files changed, 127 insertions, 5 deletions

diff --git a/techlibs/machxo2/Makefile.inc b/techlibs/machxo2/Makefile.inc
index acc32659d..35fb79fc5 100644
--- a/techlibs/machxo2/Makefile.inc
+++ b/techlibs/machxo2/Makefile.inc
@@ -9,3 +9,4 @@ $(eval $(call add_share_file,share/machxo2,techlibs/machxo2/lutrams.txt))
 $(eval $(call add_share_file,share/machxo2,techlibs/machxo2/lutrams_map.v))
 $(eval $(call add_share_file,share/machxo2,techlibs/machxo2/brams.txt))
 $(eval $(call add_share_file,share/machxo2,techlibs/machxo2/brams_map.v))
+$(eval $(call add_share_file,share/machxo2,techlibs/machxo2/arith_map.v))
diff --git a/techlibs/machxo2/arith_map.v b/techlibs/machxo2/arith_map.v
new file mode 100644
index 000000000..ab4a6b1da
--- /dev/null
+++ b/techlibs/machxo2/arith_map.v
@@ -0,0 +1,90 @@
+/*
+ *  yosys -- Yosys Open SYnthesis Suite
+ *
+ *  Copyright (C) 2012  Claire Xenia Wolf <claire@yosyshq.com>
+ *  Copyright (C) 2018  gatecat <gatecat@ds0.me>
+ *
+ *  Permission to use, copy, modify, and/or distribute this software for any
+ *  purpose with or without fee is hereby granted, provided that the above
+ *  copyright notice and this permission notice appear in all copies.
+ *
+ *  THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ *  WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ *  MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ *  ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ *  WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ *  ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ *  OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ *
+ */
+
+(* techmap_celltype = "$alu" *)
+module _80_ecp5_alu (A, B, CI, BI, X, Y, CO);
+	parameter A_SIGNED = 0;
+	parameter B_SIGNED = 0;
+	parameter A_WIDTH = 1;
+	parameter B_WIDTH = 1;
+	parameter Y_WIDTH = 1;
+
+	(* force_downto *)
+	input [A_WIDTH-1:0] A;
+	(* force_downto *)
+	input [B_WIDTH-1:0] B;
+	(* force_downto *)
+	output [Y_WIDTH-1:0] X, Y;
+
+	input CI, BI;
+	(* force_downto *)
+	output [Y_WIDTH-1:0] CO;
+
+	wire _TECHMAP_FAIL_ = Y_WIDTH <= 4;
+
+	(* force_downto *)
+	wire [Y_WIDTH-1:0] A_buf, B_buf;
+	\$pos #(.A_SIGNED(A_SIGNED), .A_WIDTH(A_WIDTH), .Y_WIDTH(Y_WIDTH)) A_conv (.A(A), .Y(A_buf));
+	\$pos #(.A_SIGNED(B_SIGNED), .A_WIDTH(B_WIDTH), .Y_WIDTH(Y_WIDTH)) B_conv (.A(B), .Y(B_buf));
+
+	function integer round_up2;
+		input integer N;
+		begin
+			round_up2 = ((N + 1) / 2) * 2;
+		end
+	endfunction
+
+	localparam Y_WIDTH2 = round_up2(Y_WIDTH);
+
+	(* force_downto *)
+	wire [Y_WIDTH2-1:0] AA = A_buf;
+	(* force_downto *)
+	wire [Y_WIDTH2-1:0] BB = BI ? ~B_buf : B_buf;
+	(* force_downto *)
+	wire [Y_WIDTH2-1:0] BX = B_buf;
+	(* force_downto *)
+	wire [Y_WIDTH2-1:0] C = {CO, CI};
+	(* force_downto *)
+	wire [Y_WIDTH2-1:0] FCO, Y1;
+
+	genvar i;
+	generate for (i = 0; i < Y_WIDTH2; i = i + 2) begin:slice
+		CCU2D #(
+			.INIT0(16'b0101_1010_1001_0110),
+			.INIT1(16'b0101_1010_1001_0110),
+			.INJECT1_0("NO"),
+			.INJECT1_1("NO")
+		) ccu2d_i (
+			.CIN(C[i]),
+			.A0(AA[i]), .B0(BX[i]), .C0(BI), .D0(1'b0),
+			.A1(AA[i+1]), .B1(BX[i+1]), .C1(BI), .D1(1'b0),
+			.S0(Y[i]), .S1(Y1[i]),
+			.COUT(FCO[i])
+		);
+
+		assign CO[i] = (AA[i] && BB[i]) || (C[i] && (AA[i] || BB[i]));
+		if (i+1 < Y_WIDTH) begin
+			assign CO[i+1] = FCO[i];
+			assign Y[i+1] = Y1[i];
+		end
+	end endgenerate
+
+	assign X = AA ^ BB;
+endmodule
diff --git a/techlibs/machxo2/cells_sim.v b/techlibs/machxo2/cells_sim.v
index 86fc0cd8e..f69c6d1e9 100644
--- a/techlibs/machxo2/cells_sim.v
+++ b/techlibs/machxo2/cells_sim.v
@@ -255,6 +255,26 @@ module DPR16X4C (
 	assign DO = ram[RAD];
 endmodule
 
+// ---------------------------------------
+(* blackbox *)
+module CCU2D (
+   CIN,
+   A0, B0, C0, D0,
+   A1, B1, C1, D1,
+   S0, S1, COUT
+);
+
+input CIN;
+input A0, B0, C0, D0;
+input A1, B1, C1, D1;
+output S0, S1, COUT;
+
+parameter [15:0] INIT0 = 16'h0000;
+parameter [15:0] INIT1 = 16'h0000;
+parameter INJECT1_0 = "YES";
+parameter INJECT1_1 = "YES";
+endmodule
+
 (* blackbox *)
 module DP8KC(
   input DIA8, DIA7, DIA6, DIA5, DIA4, DIA3, DIA2, DIA1, DIA0,
diff --git a/techlibs/machxo2/synth_machxo2.cc b/techlibs/machxo2/synth_machxo2.cc
index 4ca6351bd..3008527e0 100644
--- a/techlibs/machxo2/synth_machxo2.cc
+++ b/techlibs/machxo2/synth_machxo2.cc
@@ -69,6 +69,9 @@ struct SynthMachXO2Pass : public ScriptPass
 		log("    -noiopad\n");
 		log("        do not insert IO buffers\n");
 		log("\n");
+		log("    -ccu2\n");
+		log("        use CCU2 cells in output netlist\n");
+		log("\n");
 		log("    -vpr\n");
 		log("        generate an output netlist (and BLIF file) suitable for VPR\n");
 		log("        (this feature is experimental and incomplete)\n");
@@ -80,7 +83,7 @@ struct SynthMachXO2Pass : public ScriptPass
 	}
 
 	string top_opt, blif_file, edif_file, json_file;
-	bool nobram, nolutram, flatten, vpr, noiopad;
+	bool ccu2, nobram, nolutram, flatten, vpr, noiopad;
 
 	void clear_flags() override
 	{
@@ -88,6 +91,7 @@ struct SynthMachXO2Pass : public ScriptPass
 		blif_file = "";
 		edif_file = "";
 		json_file = "";
+		ccu2 = false;
 		nobram = false;
 		nolutram = false;
 		flatten = true;
@@ -147,6 +151,10 @@ struct SynthMachXO2Pass : public ScriptPass
 				noiopad = true;
 				continue;
 			}
+			if (args[argidx] == "-ccu2") {
+				ccu2 = true;
+				continue;
+			}
 			if (args[argidx] == "-vpr") {
 				vpr = true;
 				continue;
@@ -204,14 +212,17 @@ struct SynthMachXO2Pass : public ScriptPass
 
 		if (check_label("fine"))
 		{
+			run("opt -fast -mux_undef -undriven -fine");
 			run("memory_map");
-			run("opt -full");
-			run("techmap -map +/techmap.v");
-			run("opt -fast");
+			run("opt -undriven -fine");
 		}
 
-		if (check_label("map_ios", "(unless -noiopad)"))
+		if (check_label("map_gates", "(unless -noiopad)"))
 		{
+			if (!ccu2)
+				run("techmap");
+			else
+				run("techmap -map +/techmap.v -map +/machxo2/arith_map.v");
 			if (!noiopad || help_mode)
 			{
 				run("iopadmap -bits -outpad OB I:O -inpad IB O:I -toutpad OBZ ~T:I:O -tinoutpad BB ~T:O:I:B A:top", "(only if '-iopad')");