Merge remote-tracking branch 'origin/master' into xc7srl

33 files changed, 1656 insertions, 402 deletions

diff --git a/techlibs/achronix/speedster22i/cells_sim.v b/techlibs/achronix/speedster22i/cells_sim.v
index a94dce9b1..a0c60b4be 100755
--- a/techlibs/achronix/speedster22i/cells_sim.v
+++ b/techlibs/achronix/speedster22i/cells_sim.v
@@ -30,7 +30,7 @@ endmodule
 module PADOUT (output padout, input padin, input oe);
    assign padout  = padin;
    assign oe = oe;
-endmodule 
+endmodule
 
 module LUT4 (output dout,
              input  din0, din1, din2, din3);
@@ -66,14 +66,14 @@ always @(dataa_w or datab_w or datac_w or datad_w) begin
                          datac_w, datad_w);
 end
 assign dout = combout_rt & 1'b1;
-endmodule 
+endmodule
 
 module DFF (output q,
             input  d, ck);
    reg             q;
    always @(posedge ck)
      q <= d;
-   
+
 endmodule
 
 
diff --git a/techlibs/anlogic/anlogic_eqn.cc b/techlibs/anlogic/anlogic_eqn.cc
index c025c65c4..741bf04cc 100644
--- a/techlibs/anlogic/anlogic_eqn.cc
+++ b/techlibs/anlogic/anlogic_eqn.cc
@@ -52,13 +52,13 @@ struct AnlogicEqnPass : public Pass {
 						eqn += names[j];
 					else
 						eqn += std::string("~") + names[j];
-					
+
 					if (j!=(inputs-1)) eqn += "*";
 				}
 				eqn += ")+";
 			}
 		}
-		if (eqn.empty()) return Const("0");		
+		if (eqn.empty()) return Const("0");
 		eqn = eqn.substr(0, eqn.length()-1);
 		return Const(eqn);
 	}
diff --git a/techlibs/ecp5/Makefile.inc b/techlibs/ecp5/Makefile.inc
index 8df02be5f..4db087e87 100644
--- a/techlibs/ecp5/Makefile.inc
+++ b/techlibs/ecp5/Makefile.inc
@@ -1,5 +1,5 @@
 
-OBJS += techlibs/ecp5/synth_ecp5.o
+OBJS += techlibs/ecp5/synth_ecp5.o techlibs/ecp5/ecp5_ffinit.o
 
 $(eval $(call add_share_file,share/ecp5,techlibs/ecp5/cells_map.v))
 $(eval $(call add_share_file,share/ecp5,techlibs/ecp5/cells_sim.v))
diff --git a/techlibs/ecp5/arith_map.v b/techlibs/ecp5/arith_map.v
index 1094c5f8a..eb7947601 100644
--- a/techlibs/ecp5/arith_map.v
+++ b/techlibs/ecp5/arith_map.v
@@ -33,7 +33,7 @@ module _80_ecp5_alu (A, B, CI, BI, X, Y, CO);
 	input CI, BI;
 	output [Y_WIDTH-1:0] CO;
 
-	wire _TECHMAP_FAIL_ = Y_WIDTH <= 2;
+	wire _TECHMAP_FAIL_ = Y_WIDTH <= 4;
 
 	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));
diff --git a/techlibs/ecp5/cells_bb.v b/techlibs/ecp5/cells_bb.v
index 425d62d24..223e19b9e 100644
--- a/techlibs/ecp5/cells_bb.v
+++ b/techlibs/ecp5/cells_bb.v
@@ -156,6 +156,41 @@ module OSCG(
 parameter DIV = 128;
 endmodule
 
+(* blackbox *) (* keep *)
+module USRMCLK(
+	input USRMCLKI, USRMCLKTS,
+	output USRMCLKO
+);
+endmodule
+
+(* blackbox *) (* keep *)
+module JTAGG(
+	input TCK, TMS, TDI, JTDO2, JTDO1,
+	output TDO, JTDI, JTCK, JRTI2, JRTI1,
+	output JSHIFT, JUPDATE, JRSTN, JCE2, JCE1
+);
+parameter ER1 = "ENABLED";
+parameter ER2 = "ENABLED";
+endmodule
+
+(* blackbox *)
+module DELAYF(
+	input A, LOADN, MOVE, DIRECTION,
+	output Z, CFLAG
+);
+	parameter DEL_MODE = "USER_DEFINED";
+	parameter DEL_VALUE = 0;
+endmodule
+
+(* blackbox *)
+module DELAYG(
+	input A,
+	output Z
+);
+	parameter DEL_MODE = "USER_DEFINED";
+	parameter DEL_VALUE = 0;
+endmodule
+
 (* blackbox *)
 module IDDRX1F(
 	input D, SCLK, RST,
@@ -165,6 +200,31 @@ module IDDRX1F(
 endmodule
 
 (* blackbox *)
+module IDDRX2F(
+	input D, SCLK, ECLK, RST,
+	output Q0, Q1, Q2, Q3
+);
+	parameter GSR = "ENABLED";
+endmodule
+
+(* blackbox *)
+module IDDR71B(
+	input D, SCLK, ECLK, RST, ALIGNWD,
+	output Q0, Q1, Q2, Q3, Q4, Q5, Q6
+);
+	parameter GSR = "ENABLED";
+endmodule
+
+(* blackbox *)
+module IDDRX2DQA(
+	input D, DQSR90, ECLK, SCLK, RST,
+	input RDPNTR2, RDPNTR1, RDPNTR0, WRPNTR2, WRPNTR1, WRPNTR0,
+	output Q0, Q1, Q2, Q3, QWL
+);
+	parameter GSR = "ENABLED";
+endmodule
+
+(* blackbox *)
 module ODDRX1F(
 	input SCLK, RST, D0, D1,
 	output Q
@@ -173,6 +233,91 @@ module ODDRX1F(
 endmodule
 
 (* blackbox *)
+module ODDRX2F(
+	input SCLK, ECLK, RST, D0, D1, D2, D3,
+	output Q
+);
+	parameter GSR = "ENABLED";
+endmodule
+
+(* blackbox *)
+module ODDR71B(
+	input SCLK, ECLK, RST, D0, D1, D2, D3, D4, D5, D6,
+	output Q
+);
+	parameter GSR = "ENABLED";
+endmodule
+
+(* blackbox *)
+module OSHX2A(
+	input D0, D1, RST, ECLK, SCLK,
+	output Q
+);
+	parameter GSR = "ENABLED";
+endmodule
+
+(* blackbox *)
+module ODDRX2DQA(
+	input D0, D1, D2, D3, RST, ECLK, SCLK, DQSW270,
+	output Q
+);
+	parameter GSR = "ENABLED";
+endmodule
+
+(* blackbox *)
+module ODDRX2DQSB(
+	input D0, D1, D2, D3, RST, ECLK, SCLK, DQSW,
+	output Q
+);
+	parameter GSR = "ENABLED";
+endmodule
+
+(* blackbox *)
+module TSHX2DQA(
+	input T0, T1, SCLK, ECLK, DQSW270, RST,
+	output Q
+);
+	parameter GSR = "ENABLED";
+	parameter REGSET = "SET";
+endmodule
+
+(* blackbox *)
+module TSHX2DQSA(
+	input T0, T1, SCLK, ECLK, DQSW, RST,
+	output Q
+);
+	parameter GSR = "ENABLED";
+	parameter REGSET = "SET";
+endmodule
+
+(* blackbox *)
+module DQSBUFM(
+	input DQSI, READ1, READ0, READCLKSEL2, READCLKSEL1, READCLKSEL0, DDRDEL,
+	input ECLK, SCLK,
+	input DYNDELAY7, DYNDELAY6, DYNDELAY5, DYNDELAY4,
+	input DYNDELAY3, DYNDELAY2, DYNDELAY1, DYNDELAY0, 
+	input RST, RDLOADN, RDMOVE, RDDIRECTION, WRLOADN, WRMOVE, WRDIRECTION, PAUSE,
+	output DQSR90, DQSW, DQSW270,
+	output RDPNTR2, RDPNTR1, RDPNTR0, WRPNTR2, WRPNTR1, WRPNTR0,
+	output DATAVALID, BURSTDET, RDCFLAG, WRCFLAG
+);
+	parameter DQS_LI_DEL_ADJ = "FACTORYONLY";
+	parameter DQS_LI_DEL_VAL = 0;
+	parameter DQS_LO_DEL_ADJ = "FACTORYONLY";
+	parameter DQS_LO_DEL_VAL = 0;
+	parameter GSR = "ENABLED";
+endmodule
+
+(* blackbox *)
+module DDRDLLA(
+	input CLK, RST, UDDCNTLN, FREEZE,
+	output LOCK, DDRDEL, DCNTL7, DCNTL6, DCNTL5, DCNTL4, DCNTL3, DCNTL2, DCNTL1, DCNTL0
+);
+	parameter FORCE_MAX_DELAY = "NO";
+	parameter GSR = "ENABLED";
+endmodule
+
+(* blackbox *)
 module CLKDIVF(
 	input CLKI, RST, ALIGNWD,
 	output CDIVX
@@ -182,6 +327,13 @@ module CLKDIVF(
 endmodule
 
 (* blackbox *)
+module ECLKSYNCB(
+	input ECLKI, STOP,
+	output ECLKO
+);
+endmodule
+
+(* blackbox *)
 module DCCA(
 	input CLKI, CE,
 	output CLKO
diff --git a/techlibs/ecp5/cells_map.v b/techlibs/ecp5/cells_map.v
index 23182bdeb..6ab4b69f2 100644
--- a/techlibs/ecp5/cells_map.v
+++ b/techlibs/ecp5/cells_map.v
@@ -47,6 +47,9 @@ module  \$__DFFSE_NP1 (input D, C, E, R, output Q); TRELLIS_FF #(.GSR("DISABLED"
 module  \$__DFFSE_PP0 (input D, C, E, R, output Q); TRELLIS_FF #(.GSR("DISABLED"), .CEMUX("CE"), .CLKMUX("CLK"), .LSRMUX("LSR"), .REGSET("RESET"), .SRMODE("LSR_OVER_CE"))  _TECHMAP_REPLACE_ (.CLK(C), .CE(E), .LSR(R), .DI(D), .Q(Q)); endmodule
 module  \$__DFFSE_PP1 (input D, C, E, R, output Q); TRELLIS_FF #(.GSR("DISABLED"), .CEMUX("CE"), .CLKMUX("CLK"), .LSRMUX("LSR"), .REGSET("SET"), .SRMODE("LSR_OVER_CE"))  _TECHMAP_REPLACE_ (.CLK(C), .CE(E), .LSR(R), .DI(D), .Q(Q)); endmodule
 
+// For Diamond compatibility, FIXME: add all Diamond flipflop mappings
+module FD1S3BX(input PD, D, CK, output Q); TRELLIS_FF #(.GSR("DISABLED"), .CEMUX("1"), .CLKMUX("CLK"), .LSRMUX("LSR"), .REGSET("SET"), .SRMODE("ASYNC"))  _TECHMAP_REPLACE_ (.CLK(CK), .LSR(PD), .DI(D), .Q(Q)); endmodule
+
 `ifndef NO_LUT
 module \$lut (A, Y);
     parameter WIDTH = 0;
diff --git a/techlibs/ecp5/cells_sim.v b/techlibs/ecp5/cells_sim.v
index 507ab1beb..1e4002ee0 100644
--- a/techlibs/ecp5/cells_sim.v
+++ b/techlibs/ecp5/cells_sim.v
@@ -57,7 +57,7 @@ module TRELLIS_RAM16X2 (
 	input RAD0, RAD1, RAD2, RAD3,
 	output DO0, DO1
 );
-  	parameter WCKMUX = "WCK";
+	parameter WCKMUX = "WCK";
 	parameter WREMUX = "WRE";
 	parameter INITVAL_0 = 16'h0000;
 	parameter INITVAL_1 = 16'h0000;
@@ -104,7 +104,7 @@ module TRELLIS_DPR16X4 (
 	input [3:0] RAD,
 	output [3:0] DO
 );
-  	parameter WCKMUX = "WCK";
+	parameter WCKMUX = "WCK";
 	parameter WREMUX = "WRE";
 	parameter [63:0] INITVAL = 64'h0000000000000000;
 
@@ -203,13 +203,14 @@ endmodule
 
 // ---------------------------------------
 
-module TRELLIS_FF(input CLK, LSR, CE, DI, output reg Q);
+module TRELLIS_FF(input CLK, LSR, CE, DI, M, output reg Q);
 	parameter GSR = "ENABLED";
 	parameter [127:0] CEMUX = "1";
 	parameter CLKMUX = "CLK";
 	parameter LSRMUX = "LSR";
 	parameter SRMODE = "LSR_OVER_CE";
 	parameter REGSET = "RESET";
+	parameter [127:0] LSRMODE = "LSR";
 
 	reg muxce;
 	always @(*)
@@ -222,8 +223,13 @@ module TRELLIS_FF(input CLK, LSR, CE, DI, output reg Q);
 
 	wire muxlsr = (LSRMUX == "INV") ? ~LSR : LSR;
 	wire muxclk = (CLKMUX == "INV") ? ~CLK : CLK;
-
-	localparam srval = (REGSET == "SET") ? 1'b1 : 1'b0;
+	wire srval;
+	generate
+		if (LSRMODE == "PRLD")
+			assign srval = M;
+		else
+			assign srval = (REGSET == "SET") ? 1'b1 : 1'b0;
+	endgenerate
 
 	initial Q = srval;
 
@@ -339,6 +345,8 @@ module TRELLIS_SLICE(
 	parameter REG1_SD = "0";
 	parameter REG0_REGSET = "RESET";
 	parameter REG1_REGSET = "RESET";
+	parameter REG0_LSRMODE = "LSR";
+	parameter REG1_LSRMODE = "LSR";
 	parameter [127:0] CCU2_INJECT1_0 = "NO";
 	parameter [127:0] CCU2_INJECT1_1 = "NO";
 	parameter WREMUX = "WRE";
@@ -428,10 +436,11 @@ module TRELLIS_SLICE(
 		.CLKMUX(CLKMUX),
 		.LSRMUX(LSRMUX),
 		.SRMODE(SRMODE),
-		.REGSET(REG0_REGSET)
+		.REGSET(REG0_REGSET),
+		.LSRMODE(REG0_LSRMODE)
 	) ff_0 (
 		.CLK(CLK), .LSR(LSR), .CE(CE),
-		.DI(muxdi0),
+		.DI(muxdi0), .M(M0),
 		.Q(Q0)
 	);
 	TRELLIS_FF #(
@@ -440,10 +449,11 @@ module TRELLIS_SLICE(
 		.CLKMUX(CLKMUX),
 		.LSRMUX(LSRMUX),
 		.SRMODE(SRMODE),
-		.REGSET(REG1_REGSET)
+		.REGSET(REG1_REGSET),
+		.LSRMODE(REG1_LSRMODE)
 	) ff_1 (
 		.CLK(CLK), .LSR(LSR), .CE(CE),
-		.DI(muxdi1),
+		.DI(muxdi1), .M(M1),
 		.Q(Q1)
 	);
 endmodule
@@ -547,3 +557,20 @@ module DP16KD(
   parameter INITVAL_3E = 320'h00000000000000000000000000000000000000000000000000000000000000000000000000000000;
   parameter INITVAL_3F = 320'h00000000000000000000000000000000000000000000000000000000000000000000000000000000;
 endmodule
+
+// For Diamond compatibility, FIXME: add all Diamond flipflop mappings
+module FD1S3BX(input PD, D, CK, output Q);
+	TRELLIS_FF #(
+		.GSR("DISABLED"),
+		.CEMUX("1"),
+		.CLKMUX("CLK"),
+		.LSRMUX("LSR"),
+		.REGSET("SET"),
+		.SRMODE("ASYNC")
+	) tff_i (
+		.CLK(CK),
+		.LSR(PD),
+		.DI(D),
+		.Q(Q)
+	);
+endmodule
diff --git a/techlibs/ecp5/ecp5_ffinit.cc b/techlibs/ecp5/ecp5_ffinit.cc
new file mode 100644
index 000000000..dbd16cac9
--- /dev/null
+++ b/techlibs/ecp5/ecp5_ffinit.cc
@@ -0,0 +1,203 @@
+/*
+ *  yosys -- Yosys Open SYnthesis Suite
+ *
+ *  Copyright (C) 2012  Clifford Wolf <clifford@clifford.at>
+ *  Copyright (C) 2018-19  David Shah <david@symbioticeda.com>
+ *
+ *  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.
+ *
+ */
+
+#include "kernel/yosys.h"
+#include "kernel/sigtools.h"
+
+USING_YOSYS_NAMESPACE
+PRIVATE_NAMESPACE_BEGIN
+
+struct Ecp5FfinitPass : public Pass {
+	Ecp5FfinitPass() : Pass("ecp5_ffinit", "ECP5: handle FF init values") { }
+	void help() YS_OVERRIDE
+	{
+		//   |---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|
+		log("\n");
+		log("    ecp5_ffinit [options] [selection]\n");
+		log("\n");
+		log("Remove init values for FF output signals when equal to reset value.\n");
+		log("If reset is not used, set the reset value to the init value, otherwise\n");
+		log("unmap out the reset (if not an async reset).\n");
+	}
+	void execute(std::vector<std::string> args, RTLIL::Design *design) YS_OVERRIDE
+	{
+		log_header(design, "Executing ECP5_FFINIT pass (implement FF init values).\n");
+
+		size_t argidx;
+		for (argidx = 1; argidx < args.size(); argidx++)
+		{
+			// if (args[argidx] == "-singleton") {
+			// 	singleton_mode = true;
+			// 	continue;
+			// }
+			break;
+		}
+		extra_args(args, argidx, design);
+
+		for (auto module : design->selected_modules())
+		{
+			log("Handling FF init values in %s.\n", log_id(module));
+
+			SigMap sigmap(module);
+			pool<Wire*> init_wires;
+			dict<SigBit, State> initbits;
+			dict<SigBit, SigBit> initbit_to_wire;
+			pool<SigBit> handled_initbits;
+
+			for (auto wire : module->selected_wires())
+			{
+				if (wire->attributes.count("\\init") == 0)
+					continue;
+
+				SigSpec wirebits = sigmap(wire);
+				Const initval = wire->attributes.at("\\init");
+				init_wires.insert(wire);
+
+				for (int i = 0; i < GetSize(wirebits) && i < GetSize(initval); i++)
+				{
+					SigBit bit = wirebits[i];
+					State val = initval[i];
+
+					if (val != State::S0 && val != State::S1)
+						continue;
+
+					if (initbits.count(bit)) {
+						if (initbits.at(bit) != val) {
+							log_warning("Conflicting init values for signal %s (%s = %s, %s = %s).\n",
+									log_signal(bit), log_signal(SigBit(wire, i)), log_signal(val),
+									log_signal(initbit_to_wire[bit]), log_signal(initbits.at(bit)));
+							initbits.at(bit) = State::Sx;
+						}
+						continue;
+					}
+
+					initbits[bit] = val;
+					initbit_to_wire[bit] = SigBit(wire, i);
+				}
+			}
+			for (auto cell : module->selected_cells())
+			{
+				if (cell->type != "\\TRELLIS_FF")
+					continue;
+				SigSpec sig_d = cell->getPort("\\DI");
+				SigSpec sig_q = cell->getPort("\\Q");
+				SigSpec sig_lsr = cell->getPort("\\LSR");
+
+				if (GetSize(sig_d) < 1 || GetSize(sig_q) < 1)
+					continue;
+
+				SigBit bit_d = sigmap(sig_d[0]);
+				SigBit bit_q = sigmap(sig_q[0]);
+
+				std::string regset = "RESET";
+				if (cell->hasParam("\\REGSET"))
+					regset = cell->getParam("\\REGSET").decode_string();
+				State resetState;
+				if (regset == "SET")
+					resetState = State::S1;
+				else if (regset == "RESET")
+					resetState = State::S0;
+				else
+					log_error("FF cell %s has illegal REGSET value %s.\n",
+						log_id(cell), regset.c_str());
+
+				if (!initbits.count(bit_q))
+					continue;
+
+				State val = initbits.at(bit_q);
+
+				if (val == State::Sx)
+					continue;
+
+				log("FF init value for cell %s (%s): %s = %c\n", log_id(cell), log_id(cell->type),
+						log_signal(bit_q), val != State::S0 ? '1' : '0');
+				// Initval is the same as the reset state. Matches hardware, nowt more to do
+				if (val == resetState) {
+					handled_initbits.insert(bit_q);
+					continue;
+				}
+
+				if (GetSize(sig_lsr) >= 1 && sig_lsr[0] != State::S0) {
+					std::string srmode = "LSR_OVER_CE";
+					if (cell->hasParam("\\SRMODE"))
+						srmode = cell->getParam("\\SRMODE").decode_string();
+					if (srmode == "ASYNC") {
+						log("Async reset value %c for FF cell %s inconsistent with init value %c.\n",
+							resetState != State::S0 ? '1' : '0', log_id(cell), val != State::S0 ? '1' : '0');
+					} else {
+						SigBit bit_lsr = sigmap(sig_lsr[0]);
+						Wire *new_bit_d = module->addWire(NEW_ID);
+						if (resetState == State::S0) {
+							module->addAndnotGate(NEW_ID, bit_d, bit_lsr, new_bit_d);
+						} else {
+							module->addOrGate(NEW_ID, bit_d, bit_lsr, new_bit_d);
+						}
+
+						cell->setPort("\\DI", new_bit_d);
+						cell->setPort("\\LSR", State::S0);
+
+						if(cell->hasPort("\\CE")) {
+							std::string cemux = "CE";
+							if (cell->hasParam("\\CEMUX"))
+								cemux = cell->getParam("\\CEMUX").decode_string();
+							SigSpec sig_ce = cell->getPort("\\CE");
+							if (GetSize(sig_ce) >= 1) {
+								SigBit bit_ce = sigmap(sig_ce[0]);
+								Wire *new_bit_ce = module->addWire(NEW_ID);
+								if (cemux == "INV")
+									module->addAndnotGate(NEW_ID, bit_ce, bit_lsr, new_bit_ce);
+								else
+									module->addOrGate(NEW_ID, bit_ce, bit_lsr, new_bit_ce);
+								cell->setPort("\\CE", new_bit_ce);
+							}
+						}
+						cell->setParam("\\REGSET", val != State::S0 ? Const("SET") : Const("RESET"));
+						handled_initbits.insert(bit_q);
+					}
+				} else {
+					cell->setParam("\\REGSET", val != State::S0 ? Const("SET") : Const("RESET"));
+					handled_initbits.insert(bit_q);
+				}
+			}
+
+			for (auto wire : init_wires)
+			{
+				if (wire->attributes.count("\\init") == 0)
+					continue;
+
+				SigSpec wirebits = sigmap(wire);
+				Const &initval = wire->attributes.at("\\init");
+				bool remove_attribute = true;
+
+				for (int i = 0; i < GetSize(wirebits) && i < GetSize(initval); i++) {
+					if (handled_initbits.count(wirebits[i]))
+						initval[i] = State::Sx;
+					else if (initval[i] != State::Sx)
+						remove_attribute = false;
+				}
+
+				if (remove_attribute)
+					wire->attributes.erase("\\init");
+			}
+		}
+	}
+} Ecp5FfinitPass;
+
+PRIVATE_NAMESPACE_END
diff --git a/techlibs/ecp5/synth_ecp5.cc b/techlibs/ecp5/synth_ecp5.cc
index bda03d251..4b889d672 100644
--- a/techlibs/ecp5/synth_ecp5.cc
+++ b/techlibs/ecp5/synth_ecp5.cc
@@ -255,10 +255,7 @@ struct SynthEcp5Pass : public ScriptPass
 			run("techmap -D NO_LUT -map +/ecp5/cells_map.v");
 			run("opt_expr -mux_undef");
 			run("simplemap");
-			// TODO
-#if 0
 			run("ecp5_ffinit");
-#endif
 		}
 
 		if (check_label("map_luts"))
diff --git a/techlibs/gowin/arith_map.v b/techlibs/gowin/arith_map.v
index 25e789e4a..e15de6423 100644
--- a/techlibs/gowin/arith_map.v
+++ b/techlibs/gowin/arith_map.v
@@ -25,24 +25,24 @@ module _80_gw1n_alu(A, B, CI, BI, X, Y, CO);
    parameter A_WIDTH = 1;
    parameter B_WIDTH = 1;
    parameter Y_WIDTH = 1;
-   
+
    input [A_WIDTH-1:0] A;
    input [B_WIDTH-1:0] B;
    output [Y_WIDTH-1:0] X, Y;
-   
+
    input 		CI, BI;
    output [Y_WIDTH-1:0] CO;
-   
+
    wire 		_TECHMAP_FAIL_ = Y_WIDTH <= 2;
-   
+
    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));
-   
+
    wire [Y_WIDTH-1:0] 	AA = A_buf;
    wire [Y_WIDTH-1:0] 	BB = BI ? ~B_buf : B_buf;
    wire [Y_WIDTH-1:0] 	C = {CO, CI};
-   
+
    genvar 		i;
    generate for (i = 0; i < Y_WIDTH; i = i + 1) begin:slice
       ALU #(.ALU_MODE(32'b0))
diff --git a/techlibs/gowin/synth_gowin.cc b/techlibs/gowin/synth_gowin.cc
index 96128a680..9a3fcdbb6 100644
--- a/techlibs/gowin/synth_gowin.cc
+++ b/techlibs/gowin/synth_gowin.cc
@@ -111,7 +111,7 @@ struct SynthGowinPass : public ScriptPass
 			if (args[argidx] == "-noflatten") {
 				flatten = false;
 				continue;
-			}			
+			}
 			break;
 		}
 		extra_args(args, argidx, design);
diff --git a/techlibs/greenpak4/cells_map.v b/techlibs/greenpak4/cells_map.v
index b971a51fa..51c85183d 100644
--- a/techlibs/greenpak4/cells_map.v
+++ b/techlibs/greenpak4/cells_map.v
@@ -112,14 +112,14 @@ module GP_OBUFT(input IN, input OE, output OUT);
 endmodule
 
 module \$lut (A, Y);
-  parameter WIDTH = 0;
-  parameter LUT = 0;
+	parameter WIDTH = 0;
+	parameter LUT = 0;
 
-  input [WIDTH-1:0] A;
-  output Y;
+	input [WIDTH-1:0] A;
+	output Y;
 
-  generate
-    if (WIDTH == 1) begin
+	generate
+		if (WIDTH == 1) begin
 		if(LUT == 2'b01) begin
 			GP_INV _TECHMAP_REPLACE_ (.OUT(Y), .IN(A[0]) );
 		end
@@ -127,22 +127,22 @@ module \$lut (A, Y);
 			GP_2LUT #(.INIT({2'b00, LUT})) _TECHMAP_REPLACE_ (.OUT(Y),
 				.IN0(A[0]), .IN1(1'b0));
 		end
-    end else
-    if (WIDTH == 2) begin
-      GP_2LUT #(.INIT(LUT)) _TECHMAP_REPLACE_ (.OUT(Y),
-      	.IN0(A[0]), .IN1(A[1]));
-    end else
-    if (WIDTH == 3) begin
-      GP_3LUT #(.INIT(LUT)) _TECHMAP_REPLACE_ (.OUT(Y),
-      	.IN0(A[0]), .IN1(A[1]), .IN2(A[2]));
-    end else
-    if (WIDTH == 4) begin
-      GP_4LUT #(.INIT(LUT)) _TECHMAP_REPLACE_ (.OUT(Y),
-      	.IN0(A[0]), .IN1(A[1]), .IN2(A[2]), .IN3(A[3]));
-    end else begin
-      wire _TECHMAP_FAIL_ = 1;
-    end
-  endgenerate
+		end else
+		if (WIDTH == 2) begin
+			GP_2LUT #(.INIT(LUT)) _TECHMAP_REPLACE_ (.OUT(Y),
+				.IN0(A[0]), .IN1(A[1]));
+		end else
+		if (WIDTH == 3) begin
+			GP_3LUT #(.INIT(LUT)) _TECHMAP_REPLACE_ (.OUT(Y),
+				.IN0(A[0]), .IN1(A[1]), .IN2(A[2]));
+		end else
+		if (WIDTH == 4) begin
+			GP_4LUT #(.INIT(LUT)) _TECHMAP_REPLACE_ (.OUT(Y),
+				.IN0(A[0]), .IN1(A[1]), .IN2(A[2]), .IN3(A[3]));
+		end else begin
+			wire _TECHMAP_FAIL_ = 1;
+		end
+	endgenerate
 endmodule
 
 module \$__COUNT_ (CE, CLK, OUT, POUT, RST, UP);
diff --git a/techlibs/ice40/Makefile.inc b/techlibs/ice40/Makefile.inc
index 2750901c8..723b59d6f 100644
--- a/techlibs/ice40/Makefile.inc
+++ b/techlibs/ice40/Makefile.inc
@@ -1,5 +1,6 @@
 
 OBJS += techlibs/ice40/synth_ice40.o
+OBJS += techlibs/ice40/ice40_braminit.o
 OBJS += techlibs/ice40/ice40_ffssr.o
 OBJS += techlibs/ice40/ice40_ffinit.o
 OBJS += techlibs/ice40/ice40_opt.o
diff --git a/techlibs/ice40/brams_map.v b/techlibs/ice40/brams_map.v
index 19a61d73b..ad3bccd21 100644
--- a/techlibs/ice40/brams_map.v
+++ b/techlibs/ice40/brams_map.v
@@ -7,8 +7,8 @@ module \$__ICE40_RAM4K (
 	input  [10:0] WADDR,
 	input  [15:0] MASK, WDATA
 );
-	parameter integer READ_MODE = 0;
-	parameter integer WRITE_MODE = 0;
+	parameter [1:0] READ_MODE = 0;
+	parameter [1:0] WRITE_MODE = 0;
 	parameter [0:0] NEGCLK_R = 0;
 	parameter [0:0] NEGCLK_W = 0;
 
diff --git a/techlibs/ice40/cells_sim.v b/techlibs/ice40/cells_sim.v
index 2041693cc..62a28364b 100644
--- a/techlibs/ice40/cells_sim.v
+++ b/techlibs/ice40/cells_sim.v
@@ -326,6 +326,8 @@ module SB_RAM40_4K (
 	parameter INIT_E = 256'h0000000000000000000000000000000000000000000000000000000000000000;
 	parameter INIT_F = 256'h0000000000000000000000000000000000000000000000000000000000000000;
 
+	parameter INIT_FILE = "";
+
 `ifndef BLACKBOX
 	wire [15:0] WMASK_I;
 	wire [15:0] RMASK_I;
@@ -408,43 +410,27 @@ module SB_RAM40_4K (
 	reg [15:0] memory [0:255];
 
 	initial begin
-		for (i=0; i<16; i=i+1) begin
-`ifdef YOSYS
-			memory[ 0*16 + i] <= INIT_0[16*i +: 16];
-			memory[ 1*16 + i] <= INIT_1[16*i +: 16];
-			memory[ 2*16 + i] <= INIT_2[16*i +: 16];
-			memory[ 3*16 + i] <= INIT_3[16*i +: 16];
-			memory[ 4*16 + i] <= INIT_4[16*i +: 16];
-			memory[ 5*16 + i] <= INIT_5[16*i +: 16];
-			memory[ 6*16 + i] <= INIT_6[16*i +: 16];
-			memory[ 7*16 + i] <= INIT_7[16*i +: 16];
-			memory[ 8*16 + i] <= INIT_8[16*i +: 16];
-			memory[ 9*16 + i] <= INIT_9[16*i +: 16];
-			memory[10*16 + i] <= INIT_A[16*i +: 16];
-			memory[11*16 + i] <= INIT_B[16*i +: 16];
-			memory[12*16 + i] <= INIT_C[16*i +: 16];
-			memory[13*16 + i] <= INIT_D[16*i +: 16];
-			memory[14*16 + i] <= INIT_E[16*i +: 16];
-			memory[15*16 + i] <= INIT_F[16*i +: 16];
-`else
-			memory[ 0*16 + i] = INIT_0[16*i +: 16];
-			memory[ 1*16 + i] = INIT_1[16*i +: 16];
-			memory[ 2*16 + i] = INIT_2[16*i +: 16];
-			memory[ 3*16 + i] = INIT_3[16*i +: 16];
-			memory[ 4*16 + i] = INIT_4[16*i +: 16];
-			memory[ 5*16 + i] = INIT_5[16*i +: 16];
-			memory[ 6*16 + i] = INIT_6[16*i +: 16];
-			memory[ 7*16 + i] = INIT_7[16*i +: 16];
-			memory[ 8*16 + i] = INIT_8[16*i +: 16];
-			memory[ 9*16 + i] = INIT_9[16*i +: 16];
-			memory[10*16 + i] = INIT_A[16*i +: 16];
-			memory[11*16 + i] = INIT_B[16*i +: 16];
-			memory[12*16 + i] = INIT_C[16*i +: 16];
-			memory[13*16 + i] = INIT_D[16*i +: 16];
-			memory[14*16 + i] = INIT_E[16*i +: 16];
-			memory[15*16 + i] = INIT_F[16*i +: 16];
-`endif
-		end
+		if (INIT_FILE != "")
+			$readmemh(INIT_FILE, memory);
+		else
+			for (i=0; i<16; i=i+1) begin
+				memory[ 0*16 + i] = INIT_0[16*i +: 16];
+				memory[ 1*16 + i] = INIT_1[16*i +: 16];
+				memory[ 2*16 + i] = INIT_2[16*i +: 16];
+				memory[ 3*16 + i] = INIT_3[16*i +: 16];
+				memory[ 4*16 + i] = INIT_4[16*i +: 16];
+				memory[ 5*16 + i] = INIT_5[16*i +: 16];
+				memory[ 6*16 + i] = INIT_6[16*i +: 16];
+				memory[ 7*16 + i] = INIT_7[16*i +: 16];
+				memory[ 8*16 + i] = INIT_8[16*i +: 16];
+				memory[ 9*16 + i] = INIT_9[16*i +: 16];
+				memory[10*16 + i] = INIT_A[16*i +: 16];
+				memory[11*16 + i] = INIT_B[16*i +: 16];
+				memory[12*16 + i] = INIT_C[16*i +: 16];
+				memory[13*16 + i] = INIT_D[16*i +: 16];
+				memory[14*16 + i] = INIT_E[16*i +: 16];
+				memory[15*16 + i] = INIT_F[16*i +: 16];
+			end
 	end
 
 	always @(posedge WCLK) begin
@@ -504,6 +490,8 @@ module SB_RAM40_4KNR (
 	parameter INIT_E = 256'h0000000000000000000000000000000000000000000000000000000000000000;
 	parameter INIT_F = 256'h0000000000000000000000000000000000000000000000000000000000000000;
 
+	parameter INIT_FILE = "";
+
 	SB_RAM40_4K #(
 		.WRITE_MODE(WRITE_MODE),
 		.READ_MODE (READ_MODE ),
@@ -522,7 +510,8 @@ module SB_RAM40_4KNR (
 		.INIT_C    (INIT_C    ),
 		.INIT_D    (INIT_D    ),
 		.INIT_E    (INIT_E    ),
-		.INIT_F    (INIT_F    )
+		.INIT_F    (INIT_F    ),
+		.INIT_FILE (INIT_FILE )
 	) RAM (
 		.RDATA(RDATA),
 		.RCLK (~RCLKN),
@@ -566,6 +555,8 @@ module SB_RAM40_4KNW (
 	parameter INIT_E = 256'h0000000000000000000000000000000000000000000000000000000000000000;
 	parameter INIT_F = 256'h0000000000000000000000000000000000000000000000000000000000000000;
 
+	parameter INIT_FILE = "";
+
 	SB_RAM40_4K #(
 		.WRITE_MODE(WRITE_MODE),
 		.READ_MODE (READ_MODE ),
@@ -584,7 +575,8 @@ module SB_RAM40_4KNW (
 		.INIT_C    (INIT_C    ),
 		.INIT_D    (INIT_D    ),
 		.INIT_E    (INIT_E    ),
-		.INIT_F    (INIT_F    )
+		.INIT_F    (INIT_F    ),
+		.INIT_FILE (INIT_FILE )
 	) RAM (
 		.RDATA(RDATA),
 		.RCLK (RCLK ),
@@ -628,6 +620,8 @@ module SB_RAM40_4KNRNW (
 	parameter INIT_E = 256'h0000000000000000000000000000000000000000000000000000000000000000;
 	parameter INIT_F = 256'h0000000000000000000000000000000000000000000000000000000000000000;
 
+	parameter INIT_FILE = "";
+
 	SB_RAM40_4K #(
 		.WRITE_MODE(WRITE_MODE),
 		.READ_MODE (READ_MODE ),
@@ -646,7 +640,8 @@ module SB_RAM40_4KNRNW (
 		.INIT_C    (INIT_C    ),
 		.INIT_D    (INIT_D    ),
 		.INIT_E    (INIT_E    ),
-		.INIT_F    (INIT_F    )
+		.INIT_F    (INIT_F    ),
+		.INIT_FILE (INIT_FILE )
 	) RAM (
 		.RDATA(RDATA),
 		.RCLK (~RCLKN),
diff --git a/techlibs/ice40/ice40_braminit.cc b/techlibs/ice40/ice40_braminit.cc
new file mode 100644
index 000000000..4fa6b0792
--- /dev/null
+++ b/techlibs/ice40/ice40_braminit.cc
@@ -0,0 +1,159 @@
+/*
+ *  yosys -- Yosys Open SYnthesis Suite
+ *
+ *  Copyright (C) 2012  Clifford Wolf <clifford@clifford.at>
+ *
+ *  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.
+ *
+ */
+
+#include "kernel/yosys.h"
+#include "kernel/sigtools.h"
+#include <stdlib.h>
+#include <stdio.h>
+#include <bitset>
+
+USING_YOSYS_NAMESPACE
+PRIVATE_NAMESPACE_BEGIN
+
+static void run_ice40_braminit(Module *module)
+{
+	for (auto cell : module->selected_cells())
+	{
+		uint16_t mem[256];
+
+		/* Only consider cells we're interested in */
+		if (cell->type != "\\SB_RAM40_4K" &&
+		    cell->type != "\\SB_RAM40_4KNR" &&
+		    cell->type != "\\SB_RAM40_4KNW" &&
+		    cell->type != "\\SB_RAM40_4KNRNW")
+			continue;
+		if (!cell->hasParam("\\INIT_FILE"))
+			continue;
+		std::string init_file = cell->getParam("\\INIT_FILE").decode_string();
+		cell->unsetParam("\\INIT_FILE");
+		if (init_file == "")
+			continue;
+
+		/* Open file */
+		log("Processing %s : %s\n", RTLIL::id2cstr(cell->name), init_file.c_str());
+
+		std::ifstream f;
+		f.open(init_file.c_str());
+		if (f.fail()) {
+			log("Can not open file `%s`.\n", init_file.c_str());
+			continue;
+		}
+
+		/* Defaults to 0 */
+		memset(mem, 0x00, sizeof(mem));
+
+		/* Process each line */
+		bool in_comment = false;
+		int cursor = 0;
+
+		while (!f.eof())
+		{
+			std::string line, token;
+			std::getline(f, line);
+
+			for (int i = 0; i < GetSize(line); i++)
+			{
+				if (in_comment && line.substr(i, 2) == "*/") {
+					line[i] = ' ';
+					line[i+1] = ' ';
+					in_comment = false;
+					continue;
+				}
+				if (!in_comment && line.substr(i, 2) == "/*")
+					in_comment = true;
+				if (in_comment)
+					line[i] = ' ';
+			}
+
+			while (1)
+			{
+				bool set_cursor = false;
+				long value;
+
+				token = next_token(line, " \t\r\n");
+				if (token.empty() || token.substr(0, 2) == "//")
+					break;
+
+				if (token[0] == '@') {
+					token = token.substr(1);
+					set_cursor = true;
+				}
+
+				const char *nptr = token.c_str();
+				char *endptr;
+				value = strtol(nptr, &endptr, 16);
+				if (!*nptr || *endptr) {
+					log("Can not parse %s `%s` for %s.\n",
+						set_cursor ? "address" : "value",
+						nptr, token.c_str()
+					);
+					continue;
+				}
+
+				if (set_cursor)
+					cursor = value;
+				else if (cursor >= 0 && cursor < 256)
+					mem[cursor++] = value;
+				else
+					log("Attempt to initialize non existent address %d\n", cursor);
+			}
+		}
+
+		/* Set attributes */
+		const char *hex = "0123456789ABCDEF";
+		for (int i=0; i<16; i++) {
+			std::string val = "";
+			for (int j=15; j>=0; j--)
+				val += std::bitset<16>(mem[i*16+j]).to_string();
+			cell->setParam("\\INIT_" + std::string(1, hex[i]), RTLIL::Const::from_string(val));
+		}
+	}
+}
+
+struct Ice40BRAMInitPass : public Pass {
+	Ice40BRAMInitPass() : Pass("ice40_braminit", "iCE40: perform SB_RAM40_4K initialization from file") { }
+	void help() YS_OVERRIDE
+	{
+		//   |---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|
+		log("\n");
+		log("    ice40_braminit\n");
+		log("\n");
+		log("This command processes all SB_RAM40_4K blocks with a non-empty INIT_FILE\n");
+		log("parameter and converts it into the required INIT_x attributes\n");
+		log("\n");
+	}
+	void execute(std::vector<std::string> args, RTLIL::Design *design) YS_OVERRIDE
+	{
+		log_header(design, "Executing ICE40_BRAMINIT pass.\n");
+
+		size_t argidx;
+		for (argidx = 1; argidx < args.size(); argidx++) {
+			// if (args[argidx] == "-???") {
+			//  continue;
+			// }
+			break;
+		}
+		extra_args(args, argidx, design);
+
+		for (auto module : design->selected_modules())
+			run_ice40_braminit(module);
+	}
+} Ice40BRAMInitPass;
+
+PRIVATE_NAMESPACE_END
diff --git a/techlibs/ice40/synth_ice40.cc b/techlibs/ice40/synth_ice40.cc
index 34501b335..8899bfcc4 100644
--- a/techlibs/ice40/synth_ice40.cc
+++ b/techlibs/ice40/synth_ice40.cc
@@ -257,6 +257,7 @@ struct SynthIce40Pass : public ScriptPass
 		{
 			run("memory_bram -rules +/ice40/brams.txt");
 			run("techmap -map +/ice40/brams_map.v");
+			run("ice40_braminit");
 		}
 
 		if (check_label("map"))
diff --git a/techlibs/intel/cycloneive/arith_map.v b/techlibs/intel/cycloneive/arith_map.v
index b3a11272b..49e36aa25 100644
--- a/techlibs/intel/cycloneive/arith_map.v
+++ b/techlibs/intel/cycloneive/arith_map.v
@@ -32,7 +32,7 @@ module fa
    wire   VCC;
 
    assign VCC = 1'b1;
-   
+
    cycloneiv_lcell_comb gen_sum_0 (.combout(sum_x),
                                    .dataa(a_c),
                                    .datab(b_c),
@@ -40,7 +40,7 @@ module fa
                                    .datad(VCC));
    defparam syn__05_.lut_mask = 16'b1001011010010110;
    defparam syn__05_.sum_lutc_input = "datac";
-   
+
    cycloneiv_lcell_comb gen_cout_0 (.combout(cout_t),
                                     .dataa(cin_c),
                                     .datab(b_c),
@@ -48,11 +48,11 @@ module fa
                                     .datad(VCC));
    defparam syn__06_.lut_mask = 16'b1110000011100000;
    defparam syn__06_.sum_lutc_input = "datac";
-   
+
 endmodule // fa
 
 module f_stage();
-   
+
 endmodule // f_stage
 
 module f_end();
@@ -88,7 +88,7 @@ module _80_cycloneive_alu (A, B, CI, BI, X, Y, CO);
           .cin_c(C[0]),
           .cout_t(C0[1]),
           .sum_x(Y[0]));
-   
+
    genvar i;
    generate for (i = 1; i < Y_WIDTH; i = i + 1) begin:slice
       cycloneive_lcell_comb #(.lut_mask(16'b0101_1010_0101_0000), .sum_lutc_input("cin")) arith_cell (.combout(Y[i]), .cout(CO[i]), .dataa(BB[i]), .datab(1'b1), .datac(1'b1), .datad(1'b1), .cin(C[i]));
diff --git a/techlibs/intel/cyclonev/cells_map.v b/techlibs/intel/cyclonev/cells_map.v
index bd60d4e17..f8d142bc9 100644
--- a/techlibs/intel/cyclonev/cells_map.v
+++ b/techlibs/intel/cyclonev/cells_map.v
@@ -76,7 +76,7 @@ module \$lut (A, Y);
    wire              VCC;
    wire              GND;
    assign {VCC,GND} = {1'b1,1'b0};
-   
+
    generate
       if (WIDTH == 1) begin
 	 assign Y = ~A[0]; // Not need to spend 1 logic cell for such an easy function
@@ -151,7 +151,7 @@ module \$lut (A, Y);
                     TODO: There's not a just 7-input function on Cyclone V, see the following note:
                     **Extended LUT Mode**
                     Use extended LUT mode to implement a specific set of 7-input functions. The set must
-                    be a 2-to-1 multiplexer fed by two arbitrary 5-input functions sharing four inputs. 
+                    be a 2-to-1 multiplexer fed by two arbitrary 5-input functions sharing four inputs.
                     [source](Device Interfaces and Integration Basics for Cyclone V Devices).
                   end*/
                   else
diff --git a/techlibs/sf2/cells_map.v b/techlibs/sf2/cells_map.v
index 5b8888294..6ad7807d2 100644
--- a/techlibs/sf2/cells_map.v
+++ b/techlibs/sf2/cells_map.v
@@ -1,40 +1,54 @@
-// module  \$_DFF_N_ (input D, C, output Q); SB_DFFN _TECHMAP_REPLACE_ (.D(D), .Q(Q), .C(C)); endmodule
+module  \$_DFF_N_ (input D, C, output Q);
+  SLE _TECHMAP_REPLACE_ (.D(D), .CLK(!C), .EN(1'b1), .ALn(1'b1), .ADn(1'b1), .SLn(1'b1), .SD(1'b0), .LAT(1'b0), .Q(Q));
+endmodule
 
 module  \$_DFF_P_ (input D, C, output Q);
-  SLE _TECHMAP_REPLACE_ (
-    .D(D),
-    .CLK(C),
-    .EN(1'b1),
-    .ALn(1'b1),
-    .ADn(1'b1),
-    .SLn(1'b1),
-    .SD(1'b0),
-    .LAT(1'b0),
-    .Q(Q)
-  );
+  SLE _TECHMAP_REPLACE_ (.D(D), .CLK(C), .EN(1'b1), .ALn(1'b1), .ADn(1'b1), .SLn(1'b1), .SD(1'b0), .LAT(1'b0), .Q(Q));
+endmodule
+
+module \$_DFF_NN0_ (input D, C, R, output Q);
+  SLE _TECHMAP_REPLACE_ (.D(D), .CLK(!C), .EN(1'b1), .ALn(R), .ADn(1'b1), .SLn(1'b1), .SD(1'b0), .LAT(1'b0), .Q(Q));
+endmodule
+
+module \$_DFF_NN1_ (input D, C, R, output Q);
+  SLE _TECHMAP_REPLACE_ (.D(D), .CLK(!C), .EN(1'b1), .ALn(R), .ADn(1'b0), .SLn(1'b1), .SD(1'b0), .LAT(1'b0), .Q(Q));
+endmodule
+
+module \$_DFF_NP0_ (input D, C, R, output Q);
+  SLE _TECHMAP_REPLACE_ (.D(D), .CLK(!C), .EN(1'b1), .ALn(!R), .ADn(1'b1), .SLn(1'b1), .SD(1'b0), .LAT(1'b0), .Q(Q));
+endmodule
+
+module \$_DFF_NP1_ (input D, C, R, output Q);
+  SLE _TECHMAP_REPLACE_ (.D(D), .CLK(!C), .EN(1'b1), .ALn(!R), .ADn(1'b0), .SLn(1'b1), .SD(1'b0), .LAT(1'b0), .Q(Q));
+endmodule
+
+module \$_DFF_PN0_ (input D, C, R, output Q);
+  SLE _TECHMAP_REPLACE_ (.D(D), .CLK(C), .EN(1'b1), .ALn(R), .ADn(1'b1), .SLn(1'b1), .SD(1'b0), .LAT(1'b0), .Q(Q));
+endmodule
+
+module \$_DFF_PN1_ (input D, C, R, output Q);
+  SLE _TECHMAP_REPLACE_ (.D(D), .CLK(C), .EN(1'b1), .ALn(R), .ADn(1'b0), .SLn(1'b1), .SD(1'b0), .LAT(1'b0), .Q(Q));
+endmodule
+
+module \$_DFF_PP0_ (input D, C, R, output Q);
+  SLE _TECHMAP_REPLACE_ (.D(D), .CLK(C), .EN(1'b1), .ALn(!R), .ADn(1'b1), .SLn(1'b1), .SD(1'b0), .LAT(1'b0), .Q(Q));
+endmodule
+
+module \$_DFF_PP1_ (input D, C, R, output Q);
+  SLE _TECHMAP_REPLACE_ (.D(D), .CLK(C), .EN(1'b1), .ALn(!R), .ADn(1'b0), .SLn(1'b1), .SD(1'b0), .LAT(1'b0), .Q(Q));
 endmodule
 
 // module  \$_DFFE_NN_ (input D, C, E, output Q); SB_DFFNE _TECHMAP_REPLACE_ (.D(D), .Q(Q), .C(C), .E(!E)); endmodule
 // module  \$_DFFE_PN_ (input D, C, E, output Q); SB_DFFE  _TECHMAP_REPLACE_ (.D(D), .Q(Q), .C(C), .E(!E)); endmodule
-// 
+//
 // module  \$_DFFE_NP_ (input D, C, E, output Q); SB_DFFNE _TECHMAP_REPLACE_ (.D(D), .Q(Q), .C(C), .E(E)); endmodule
 // module  \$_DFFE_PP_ (input D, C, E, output Q); SB_DFFE  _TECHMAP_REPLACE_ (.D(D), .Q(Q), .C(C), .E(E)); endmodule
-// 
-// module  \$_DFF_NN0_ (input D, C, R, output Q); SB_DFFNR _TECHMAP_REPLACE_ (.D(D), .Q(Q), .C(C), .R(!R)); endmodule
-// module  \$_DFF_NN1_ (input D, C, R, output Q); SB_DFFNS _TECHMAP_REPLACE_ (.D(D), .Q(Q), .C(C), .S(!R)); endmodule
-// module  \$_DFF_PN0_ (input D, C, R, output Q); SB_DFFR  _TECHMAP_REPLACE_ (.D(D), .Q(Q), .C(C), .R(!R)); endmodule
-// module  \$_DFF_PN1_ (input D, C, R, output Q); SB_DFFS  _TECHMAP_REPLACE_ (.D(D), .Q(Q), .C(C), .S(!R)); endmodule
-// 
-// module  \$_DFF_NP0_ (input D, C, R, output Q); SB_DFFNR _TECHMAP_REPLACE_ (.D(D), .Q(Q), .C(C), .R(R)); endmodule
-// module  \$_DFF_NP1_ (input D, C, R, output Q); SB_DFFNS _TECHMAP_REPLACE_ (.D(D), .Q(Q), .C(C), .S(R)); endmodule
-// module  \$_DFF_PP0_ (input D, C, R, output Q); SB_DFFR  _TECHMAP_REPLACE_ (.D(D), .Q(Q), .C(C), .R(R)); endmodule
-// module  \$_DFF_PP1_ (input D, C, R, output Q); SB_DFFS  _TECHMAP_REPLACE_ (.D(D), .Q(Q), .C(C), .S(R)); endmodule
-// 
+//
 // module  \$__DFFE_NN0 (input D, C, E, R, output Q); SB_DFFNER _TECHMAP_REPLACE_ (.D(D), .Q(Q), .C(C), .E(E), .R(!R)); endmodule
 // module  \$__DFFE_NN1 (input D, C, E, R, output Q); SB_DFFNES _TECHMAP_REPLACE_ (.D(D), .Q(Q), .C(C), .E(E), .S(!R)); endmodule
 // module  \$__DFFE_PN0 (input D, C, E, R, output Q); SB_DFFER  _TECHMAP_REPLACE_ (.D(D), .Q(Q), .C(C), .E(E), .R(!R)); endmodule
 // module  \$__DFFE_PN1 (input D, C, E, R, output Q); SB_DFFES  _TECHMAP_REPLACE_ (.D(D), .Q(Q), .C(C), .E(E), .S(!R)); endmodule
-// 
+//
 // module  \$__DFFE_NP0 (input D, C, E, R, output Q); SB_DFFNER _TECHMAP_REPLACE_ (.D(D), .Q(Q), .C(C), .E(E), .R(R)); endmodule
 // module  \$__DFFE_NP1 (input D, C, E, R, output Q); SB_DFFNES _TECHMAP_REPLACE_ (.D(D), .Q(Q), .C(C), .E(E), .S(R)); endmodule
 // module  \$__DFFE_PP0 (input D, C, E, R, output Q); SB_DFFER  _TECHMAP_REPLACE_ (.D(D), .Q(Q), .C(C), .E(E), .R(R)); endmodule
diff --git a/techlibs/sf2/cells_sim.v b/techlibs/sf2/cells_sim.v
index f967068af..c62748b11 100644
--- a/techlibs/sf2/cells_sim.v
+++ b/techlibs/sf2/cells_sim.v
@@ -1,3 +1,114 @@
+// https://coredocs.s3.amazonaws.com/Libero/12_0_0/Tool/sf2_mlg.pdf
+
+module ADD2 (
+
+	input A, B,
+	output Y
+);
+	assign Y = A & B;
+endmodule
+
+module ADD3 (
+	input A, B, C,
+	output Y
+);
+	assign Y = A & B & C;
+endmodule
+
+module ADD4 (
+	input A, B, C, D,
+	output Y
+);
+	assign Y = A & B & C & D;
+endmodule
+
+module CFG1 (
+	output Y,
+	input A
+);
+	parameter [1:0] INIT = 2'h0;
+	assign Y = INIT >> A;
+endmodule
+
+module CFG2 (
+	output Y,
+	input A,
+	input B
+);
+	parameter [3:0] INIT = 4'h0;
+	assign Y = INIT >> {B, A};
+endmodule
+
+module CFG3 (
+	output Y,
+	input A,
+	input B,
+	input C
+);
+	parameter [7:0] INIT = 8'h0;
+	assign Y = INIT >> {C, B, A};
+endmodule
+
+module CFG4 (
+	output Y,
+	input A,
+	input B,
+	input C,
+	input D
+);
+	parameter [15:0] INIT = 16'h0;
+	assign Y = INIT >> {D, C, B, A};
+endmodule
+
+module BUFF (
+	input A,
+	output Y
+);
+	assign Y = A;
+endmodule
+
+module BUFD (
+	input A,
+	output Y
+);
+	assign Y = A;
+endmodule
+
+module CLKINT (
+	input A,
+	output Y
+);
+	assign Y = A;
+endmodule
+
+module CLKINT_PRESERVE (
+	input A,
+	output Y
+);
+	assign Y = A;
+endmodule
+
+module GCLKINT (
+	input A, EN,
+	output Y
+);
+	assign Y = A & EN;
+endmodule
+
+module RCLKINT (
+	input A,
+	output Y
+);
+	assign Y = A;
+endmodule
+
+module RGCLKINT (
+	input A, EN,
+	output Y
+);
+	assign Y = A & EN;
+endmodule
+
 module SLE (
 	output Q,
 	input ADn,
@@ -36,44 +147,151 @@ module SLE (
 	assign Q = LAT ? q_latch : q_ff;
 endmodule
 
-module CFG1 (
-	output Y,
-	input A
+// module AR1
+// module FCEND_BUFF
+// module FCINIT_BUFF
+// module FLASH_FREEZE
+// module OSCILLATOR
+// module SYSRESET
+// module SYSCTRL_RESET_STATUS
+// module LIVE_PROBE_FB
+// module GCLKBUF
+// module GCLKBUF_DIFF
+// module GCLKBIBUF
+// module DFN1
+// module DFN1C0
+// module DFN1E1
+// module DFN1E1C0
+// module DFN1E1P0
+// module DFN1P0
+// module DLN1
+// module DLN1C0
+// module DLN1P0
+
+module INV (
+	input A,
+	output Y
 );
-	parameter [1:0] INIT = 2'h0;
-	assign Y = INIT >> A;
+	assign Y = !A;
 endmodule
 
-module CFG2 (
-	output Y,
+module INVD (
 	input A,
-	input B
+	output Y
 );
-	parameter [3:0] INIT = 4'h0;
-	assign Y = INIT >> {B, A};
+	assign Y = !A;
 endmodule
 
-module CFG3 (
-	output Y,
-	input A,
-	input B,
-	input C
+module MX2 (
+	input A, B, S,
+	output Y
 );
-	parameter [7:0] INIT = 8'h0;
-	assign Y = INIT >> {C, B, A};
+	assign Y = S ? B : A;
 endmodule
 
-module CFG4 (
-	output Y,
-	input A,
-	input B,
-	input C,
-	input D
+module MX4 (
+	input D0, D1, D2, D3, S0, S1,
+	output Y
 );
-	parameter [15:0] INIT = 16'h0;
-	assign Y = INIT >> {D, C, B, A};
+	assign Y = S1 ? (S0 ? D3 : D2) : (S0 ? D1 : D0);
+endmodule
+
+module NAND2 (
+	input A, B,
+	output Y
+);
+	assign Y = !(A & B);
+endmodule
+
+module NAND3 (
+	input A, B, C,
+	output Y
+);
+	assign Y = !(A & B & C);
+endmodule
+
+module NAND4 (
+	input A, B, C, D,
+	output Y
+);
+	assign Y = !(A & B & C & D);
+endmodule
+
+module NOR2 (
+	input A, B,
+	output Y
+);
+	assign Y = !(A | B);
+endmodule
+
+module NOR3 (
+	input A, B, C,
+	output Y
+);
+	assign Y = !(A | B | C);
+endmodule
+
+module NOR4 (
+	input A, B, C, D,
+	output Y
+);
+	assign Y = !(A | B | C | D);
 endmodule
 
+module OR2 (
+	input A, B,
+	output Y
+);
+	assign Y = A | B;
+endmodule
+
+module OR3 (
+	input A, B, C,
+	output Y
+);
+	assign Y = A | B | C;
+endmodule
+
+module OR4 (
+	input A, B, C, D,
+	output Y
+);
+	assign Y = A | B | C | D;
+endmodule
+
+module XOR2 (
+	input A, B,
+	output Y
+);
+	assign Y = A ^ B;
+endmodule
+
+module XOR3 (
+	input A, B, C,
+	output Y
+);
+	assign Y = A ^ B ^ C;
+endmodule
+
+module XOR4 (
+	input A, B, C, D,
+	output Y
+);
+	assign Y = A ^ B ^ C ^ D;
+endmodule
+
+module XOR8 (
+	input A, B, C, D, E, F, G, H,
+	output Y
+);
+	assign Y = A ^ B ^ C ^ D ^ E ^ F ^ G ^ H;
+endmodule
+
+// module UJTAG
+// module BIBUF
+// module BIBUF_DIFF
+// module CLKBIBUF
+
 module CLKBUF (
 	input PAD,
 	output Y
@@ -81,6 +299,8 @@ module CLKBUF (
 	assign Y = PAD;
 endmodule
 
+// module CLKBUF_DIFF
+
 module INBUF (
 	input PAD,
 	output Y
@@ -88,9 +308,20 @@ module INBUF (
 	assign Y = PAD;
 endmodule
 
+// module INBUF_DIFF
+
 module OUTBUF (
 	input D,
 	output PAD
 );
 	assign PAD = D;
 endmodule
+
+// module OUTBUF_DIFF
+// module TRIBUFF
+// module TRIBUFF_DIFF
+// module DDR_IN
+// module DDR_OUT
+// module RAM1K18
+// module RAM64x18
+// module MACC
diff --git a/techlibs/sf2/sf2_iobs.cc b/techlibs/sf2/sf2_iobs.cc
index 27141430c..3d43332e2 100644
--- a/techlibs/sf2/sf2_iobs.cc
+++ b/techlibs/sf2/sf2_iobs.cc
@@ -23,6 +23,136 @@
 USING_YOSYS_NAMESPACE
 PRIVATE_NAMESPACE_BEGIN
 
+static void handle_iobufs(Module *module, bool clkbuf_mode)
+{
+	SigMap sigmap(module);
+
+	pool<SigBit> clk_bits;
+	pool<SigBit> handled_io_bits;
+	dict<SigBit, SigBit> rewrite_bits;
+	vector<pair<Cell*, SigBit>> pad_bits;
+
+	for (auto cell : module->cells())
+	{
+		if (clkbuf_mode && cell->type == "\\SLE") {
+			for (auto bit : sigmap(cell->getPort("\\CLK")))
+				clk_bits.insert(bit);
+		}
+		if (cell->type.in("\\INBUF", "\\OUTBUF", "\\TRIBUFF", "\\BIBUF", "\\CLKBUF", "\\CLKBIBUF",
+				"\\INBUF_DIFF", "\\OUTBUF_DIFF", "\\BIBUFF_DIFF", "\\TRIBUFF_DIFF", "\\CLKBUF_DIFF",
+				"\\GCLKBUF", "\\GCLKBUF_DIFF", "\\GCLKBIBUF")) {
+			for (auto bit : sigmap(cell->getPort("\\PAD")))
+				handled_io_bits.insert(bit);
+		}
+	}
+
+	for (auto wire : vector<Wire*>(module->wires()))
+	{
+		if (!wire->port_input && !wire->port_output)
+			continue;
+
+		for (int index = 0; index < GetSize(wire); index++)
+		{
+			SigBit bit(wire, index);
+			SigBit canonical_bit = sigmap(bit);
+
+			if (handled_io_bits.count(canonical_bit))
+				continue;
+
+			if (wire->port_input && wire->port_output)
+				log_error("Failed to add buffer for inout port bit %s.\n", log_signal(bit));
+
+			IdString buf_type, buf_port;
+
+			if (wire->port_output) {
+				buf_type = "\\OUTBUF";
+				buf_port = "\\D";
+			} else if (clkbuf_mode && clk_bits.count(canonical_bit)) {
+				buf_type = "\\CLKBUF";
+				buf_port = "\\Y";
+			} else {
+				buf_type = "\\INBUF";
+				buf_port = "\\Y";
+			}
+
+			Cell *c = module->addCell(NEW_ID, buf_type);
+			SigBit new_bit = module->addWire(NEW_ID);
+			c->setPort(buf_port, new_bit);
+			pad_bits.push_back(make_pair(c, bit));
+			rewrite_bits[canonical_bit] = new_bit;
+
+			log("Added %s cell %s for port bit %s.\n", log_id(c->type), log_id(c), log_signal(bit));
+		}
+	}
+
+	auto rewrite_function = [&](SigSpec &s) {
+		for (auto &bit : s) {
+			SigBit canonical_bit = sigmap(bit);
+			if (rewrite_bits.count(canonical_bit))
+				bit = rewrite_bits.at(canonical_bit);
+		}
+	};
+
+	module->rewrite_sigspecs(rewrite_function);
+
+	for (auto &it : pad_bits)
+		it.first->setPort("\\PAD", it.second);
+}
+
+static void handle_clkint(Module *module)
+{
+	SigMap sigmap(module);
+
+	pool<SigBit> clk_bits;
+	vector<SigBit> handled_clk_bits;
+
+	for (auto cell : module->cells())
+	{
+		if (cell->type == "\\SLE") {
+			for (auto bit : sigmap(cell->getPort("\\CLK")))
+				clk_bits.insert(bit);
+		}
+		if (cell->type.in("\\CLKBUF", "\\CLKBIBUF", "\\CLKBUF_DIFF", "\\GCLKBUF", "\\GCLKBUF_DIFF", "\\GCLKBIBUF",
+				"\\CLKINT", "\\CLKINT_PRESERVE", "\\GCLKINT", "\\RCLKINT", "\\RGCLKINT")) {
+			for (auto bit : sigmap(cell->getPort("\\Y")))
+				handled_clk_bits.push_back(bit);
+		}
+	}
+
+	for (auto bit : handled_clk_bits)
+		clk_bits.erase(bit);
+
+	for (auto cell : vector<Cell*>(module->cells()))
+	for (auto &conn : cell->connections())
+	{
+		if (!cell->output(conn.first))
+			continue;
+
+		SigSpec sig = conn.second;
+		bool did_something = false;
+
+		for (auto &bit : sig) {
+			SigBit canonical_bit = sigmap(bit);
+			if (clk_bits.count(canonical_bit)) {
+				Cell *c = module->addCell(NEW_ID, "\\CLKINT");
+				SigBit new_bit = module->addWire(NEW_ID);
+				c->setPort("\\A", new_bit);
+				c->setPort("\\Y", bit);
+				log("Added %s cell %s for clock signal %s.\n", log_id(c->type), log_id(c), log_signal(bit));
+				clk_bits.erase(canonical_bit);
+				did_something = true;
+				bit = new_bit;
+			}
+		}
+
+		if (did_something)
+			cell->setPort(conn.first, sig);
+	}
+
+	for (auto bit : clk_bits)
+		log_error("Failed to insert CLKINT for clock signal %s.\n", log_signal(bit));
+}
+
 struct Sf2IobsPass : public Pass {
 	Sf2IobsPass() : Pass("sf2_iobs", "SF2: insert IO buffers") { }
 	void help() YS_OVERRIDE
@@ -31,20 +161,25 @@ struct Sf2IobsPass : public Pass {
 		log("\n");
 		log("    sf2_iobs [options] [selection]\n");
 		log("\n");
-		log("Add SF2 I/O buffers to top module IOs as needed.\n");
+		log("Add SF2 I/O buffers and global buffers to top module as needed.\n");
+		log("\n");
+		log("    -clkbuf\n");
+		log("        Insert PAD->global_net clock buffers\n");
 		log("\n");
 	}
 	void execute(std::vector<std::string> args, RTLIL::Design *design) YS_OVERRIDE
 	{
+		bool clkbuf_mode = false;
+
 		log_header(design, "Executing sf2_iobs pass (insert IO buffers).\n");
 
 		size_t argidx;
 		for (argidx = 1; argidx < args.size(); argidx++)
 		{
-			// if (args[argidx] == "-singleton") {
-			// 	singleton_mode = true;
-			// 	continue;
-			// }
+			if (args[argidx] == "-clkbuf") {
+				clkbuf_mode = true;
+				continue;
+			}
 			break;
 		}
 		extra_args(args, argidx, design);
@@ -54,76 +189,8 @@ struct Sf2IobsPass : public Pass {
 		if (module == nullptr)
 			log_cmd_error("No top module found.\n");
 
-		SigMap sigmap(module);
-
-		pool<SigBit> clk_bits;
-		pool<SigBit> handled_io_bits;
-		dict<SigBit, SigBit> rewrite_bits;
-		vector<pair<Cell*, SigBit>> pad_bits;
-
-		for (auto cell : module->cells())
-		{
-			if (cell->type == "\\SLE") {
-				for (auto bit : sigmap(cell->getPort("\\CLK")))
-					clk_bits.insert(bit);
-			}
-			if (cell->type.in("\\INBUF", "\\OUTBUF", "\\CLKBUF")) {
-				for (auto bit : sigmap(cell->getPort("\\PAD")))
-					handled_io_bits.insert(bit);
-			}
-		}
-
-		for (auto wire : vector<Wire*>(module->wires()))
-		{
-			if (!wire->port_input && !wire->port_output)
-				continue;
-
-			for (int index = 0; index < GetSize(wire); index++)
-			{
-				SigBit bit(wire, index);
-				SigBit canonical_bit = sigmap(bit);
-
-				if (handled_io_bits.count(canonical_bit))
-					continue;
-
-				if (wire->port_input && wire->port_output)
-					log_error("Failed to add buffer for inout port bit %s.\n", log_signal(bit));
-
-				IdString buf_type, buf_port;
-
-				if (wire->port_output) {
-					buf_type = "\\OUTBUF";
-					buf_port = "\\D";
-				} else if (clk_bits.count(canonical_bit)) {
-					buf_type = "\\CLKBUF";
-					buf_port = "\\Y";
-				} else {
-					buf_type = "\\INBUF";
-					buf_port = "\\Y";
-				}
-
-				Cell *c = module->addCell(NEW_ID, buf_type);
-				SigBit new_bit = module->addWire(NEW_ID);
-				c->setPort(buf_port, new_bit);
-				pad_bits.push_back(make_pair(c, bit));
-				rewrite_bits[canonical_bit] = new_bit;
-
-				log("Added %s cell %s for port bit %s.\n", log_id(c->type), log_id(c), log_signal(bit));
-			}
-		}
-
-		auto rewrite_function = [&](SigSpec &s) {
-			for (auto &bit : s) {
-				SigBit canonical_bit = sigmap(bit);
-				if (rewrite_bits.count(canonical_bit))
-					bit = rewrite_bits.at(canonical_bit);
-			}
-		};
-
-		module->rewrite_sigspecs(rewrite_function);
-
-		for (auto &it : pad_bits)
-			it.first->setPort("\\PAD", it.second);
+		handle_iobufs(module, clkbuf_mode);
+		handle_clkint(module);
 	}
 } Sf2IobsPass;
 
diff --git a/techlibs/sf2/synth_sf2.cc b/techlibs/sf2/synth_sf2.cc
index bdc20456d..0924df7a6 100644
--- a/techlibs/sf2/synth_sf2.cc
+++ b/techlibs/sf2/synth_sf2.cc
@@ -63,6 +63,9 @@ struct SynthSf2Pass : public ScriptPass
 		log("    -noiobs\n");
 		log("        run synthesis in \"block mode\", i.e. do not insert IO buffers\n");
 		log("\n");
+		log("    -clkbuf\n");
+		log("        insert direct PAD->global_net buffers\n");
+		log("\n");
 		log("    -retime\n");
 		log("        run 'abc' with -dff option\n");
 		log("\n");
@@ -73,7 +76,7 @@ struct SynthSf2Pass : public ScriptPass
 	}
 
 	string top_opt, edif_file, vlog_file, json_file;
-	bool flatten, retime, iobs;
+	bool flatten, retime, iobs, clkbuf;
 
 	void clear_flags() YS_OVERRIDE
 	{
@@ -84,6 +87,7 @@ struct SynthSf2Pass : public ScriptPass
 		flatten = true;
 		retime = false;
 		iobs = true;
+		clkbuf = false;
 	}
 
 	void execute(std::vector<std::string> args, RTLIL::Design *design) YS_OVERRIDE
@@ -130,6 +134,10 @@ struct SynthSf2Pass : public ScriptPass
 				iobs = false;
 				continue;
 			}
+			if (args[argidx] == "-clkbuf") {
+				clkbuf = true;
+				continue;
+			}
 			break;
 		}
 		extra_args(args, argidx, design);
@@ -201,8 +209,10 @@ struct SynthSf2Pass : public ScriptPass
 
 		if (check_label("map_iobs"))
 		{
-			if (iobs || help_mode)
-				run("sf2_iobs", "(unless -noiobs)");
+			if (help_mode)
+				run("sf2_iobs [-clkbuf]", "(unless -noiobs)");
+			else if (iobs)
+				run(clkbuf ? "sf2_iobs -clkbuf" : "sf2_iobs");
 			run("clean");
 		}
 
diff --git a/techlibs/xilinx/Makefile.inc b/techlibs/xilinx/Makefile.inc
index 887ea27d9..d68f03bb4 100644
--- a/techlibs/xilinx/Makefile.inc
+++ b/techlibs/xilinx/Makefile.inc
@@ -28,7 +28,8 @@ $(eval $(call add_share_file,share/xilinx,techlibs/xilinx/brams_bb.v))
 $(eval $(call add_share_file,share/xilinx,techlibs/xilinx/drams.txt))
 $(eval $(call add_share_file,share/xilinx,techlibs/xilinx/drams_map.v))
 $(eval $(call add_share_file,share/xilinx,techlibs/xilinx/arith_map.v))
-$(eval $(call add_share_file,share/xilinx,techlibs/xilinx/lut2lut.v))
+$(eval $(call add_share_file,share/xilinx,techlibs/xilinx/ff_map.v))
+$(eval $(call add_share_file,share/xilinx,techlibs/xilinx/lut_map.v))
 
 $(eval $(call add_gen_share_file,share/xilinx,techlibs/xilinx/brams_init_36.vh))
 $(eval $(call add_gen_share_file,share/xilinx,techlibs/xilinx/brams_init_32.vh))
diff --git a/techlibs/xilinx/arith_map.v b/techlibs/xilinx/arith_map.v
index 03719659b..09a5f07e8 100644
--- a/techlibs/xilinx/arith_map.v
+++ b/techlibs/xilinx/arith_map.v
@@ -17,6 +17,9 @@
  *
  */
 
+// ============================================================================
+// LCU
+
 (* techmap_celltype = "$lcu" *)
 module _80_xilinx_lcu (P, G, CI, CO);
 	parameter WIDTH = 2;
@@ -28,10 +31,78 @@ module _80_xilinx_lcu (P, G, CI, CO);
 
 	wire _TECHMAP_FAIL_ = WIDTH <= 2;
 
+	genvar i;
+
+`ifdef _CLB_CARRY
+
+	localparam CARRY4_COUNT = (WIDTH + 3) / 4;
+	localparam MAX_WIDTH    = CARRY4_COUNT * 4;
+	localparam PAD_WIDTH    = MAX_WIDTH - WIDTH;
+
+	wire [MAX_WIDTH-1:0] S  = {{PAD_WIDTH{1'b0}}, P & ~G};
+	wire [MAX_WIDTH-1:0] C  = CO;
+
+	generate for (i = 0; i < CARRY4_COUNT; i = i + 1) begin:slice
+
+		// Partially occupied CARRY4
+		if ((i+1)*4 > WIDTH) begin
+
+			// First one
+			if (i == 0) begin
+				CARRY4 carry4_1st_part
+				(
+				.CYINIT(CI),
+				.CI    (1'd0),
+				.DI    (G [(Y_WIDTH - 1):i*4]),
+				.S     (S [(Y_WIDTH - 1):i*4]),
+				.CO    (CO[(Y_WIDTH - 1):i*4]),
+				);
+			// Another one
+			end else begin
+				CARRY4 carry4_part
+				(
+				.CYINIT(1'd0),
+				.CI    (C [i*4 - 1]),
+				.DI    (G [(Y_WIDTH - 1):i*4]),
+				.S     (S [(Y_WIDTH - 1):i*4]),
+				.CO    (CO[(Y_WIDTH - 1):i*4]),
+				);
+			end
+
+		// Fully occupied CARRY4
+		end else begin
+
+			// First one
+			if (i == 0) begin
+				CARRY4 carry4_1st_full
+				(
+				.CYINIT(CI),
+				.CI    (1'd0),
+				.DI    (G [((i+1)*4 - 1):i*4]),
+				.S     (S [((i+1)*4 - 1):i*4]),
+				.CO    (CO[((i+1)*4 - 1):i*4]),
+				);
+			// Another one
+			end else begin
+				CARRY4 carry4_full
+				(
+				.CYINIT(1'd0),
+				.CI    (C [i*4 - 1]),
+				.DI    (G [((i+1)*4 - 1):i*4]),
+				.S     (S [((i+1)*4 - 1):i*4]),
+				.CO    (CO[((i+1)*4 - 1):i*4]),
+				);
+			end
+
+		end
+
+	end endgenerate
+
+`elsif _EXPLICIT_CARRY
+
 	wire [WIDTH-1:0] C = {CO, CI};
 	wire [WIDTH-1:0] S = P & ~G;
 
-	genvar i;
 	generate for (i = 0; i < WIDTH; i = i + 1) begin:slice
 		MUXCY muxcy (
 			.CI(C[i]),
@@ -40,8 +111,28 @@ module _80_xilinx_lcu (P, G, CI, CO);
 			.O(CO[i])
 		);
 	end endgenerate
+
+`else
+
+	wire [WIDTH-1:0] C = {CO, CI};
+	wire [WIDTH-1:0] S = P & ~G;
+
+	generate for (i = 0; i < WIDTH; i = i + 1) begin:slice
+		MUXCY muxcy (
+			.CI(C[i]),
+			.DI(G[i]),
+			.S(S[i]),
+			.O(CO[i])
+		);
+	end endgenerate
+`endif
+
 endmodule
 
+
+// ============================================================================
+// ALU
+
 (* techmap_celltype = "$alu" *)
 module _80_xilinx_alu (A, B, CI, BI, X, Y, CO);
 	parameter A_SIGNED = 0;
@@ -49,6 +140,8 @@ module _80_xilinx_alu (A, B, CI, BI, X, Y, CO);
 	parameter A_WIDTH = 1;
 	parameter B_WIDTH = 1;
 	parameter Y_WIDTH = 1;
+	parameter _TECHMAP_CONSTVAL_CI_ = 0;
+	parameter _TECHMAP_CONSTMSK_CI_ = 0;
 
 	input [A_WIDTH-1:0] A;
 	input [B_WIDTH-1:0] B;
@@ -66,16 +159,189 @@ module _80_xilinx_alu (A, B, CI, BI, X, Y, CO);
 	wire [Y_WIDTH-1:0] AA = A_buf;
 	wire [Y_WIDTH-1:0] BB = BI ? ~B_buf : B_buf;
 
-	wire [Y_WIDTH-1:0] P = AA ^ BB;
-	wire [Y_WIDTH-1:0] G = AA & BB;
-	wire [Y_WIDTH-1:0] C = {CO, CI};
-	wire [Y_WIDTH-1:0] S = P & ~G;
+	genvar i;
+
+`ifdef _CLB_CARRY
+
+	localparam CARRY4_COUNT = (Y_WIDTH + 3) / 4;
+	localparam MAX_WIDTH    = CARRY4_COUNT * 4;
+	localparam PAD_WIDTH    = MAX_WIDTH - Y_WIDTH;
+
+	wire [MAX_WIDTH-1:0] S  = {{PAD_WIDTH{1'b0}}, AA ^ BB};
+	wire [MAX_WIDTH-1:0] DI = {{PAD_WIDTH{1'b0}}, AA & BB};
+
+	wire [MAX_WIDTH-1:0] C  = CO;
 
 	genvar i;
+	generate for (i = 0; i < CARRY4_COUNT; i = i + 1) begin:slice
+
+		// Partially occupied CARRY4
+		if ((i+1)*4 > Y_WIDTH) begin
+
+			// First one
+			if (i == 0) begin
+				CARRY4 #(.IS_INITIALIZED(1'd1)) carry4_1st_part
+				(
+				.CYINIT(CI),
+				.CI    (1'd0),
+				.DI    (DI[(Y_WIDTH - 1):i*4]),
+				.S     (S [(Y_WIDTH - 1):i*4]),
+				.O     (Y [(Y_WIDTH - 1):i*4]),
+				.CO    (CO[(Y_WIDTH - 1):i*4])
+				);
+			// Another one
+			end else begin
+				CARRY4 carry4_part
+				(
+				.CYINIT(1'd0),
+				.CI    (C [i*4 - 1]),
+				.DI    (DI[(Y_WIDTH - 1):i*4]),
+				.S     (S [(Y_WIDTH - 1):i*4]),
+				.O     (Y [(Y_WIDTH - 1):i*4]),
+				.CO    (CO[(Y_WIDTH - 1):i*4])
+				);
+			end
+
+		// Fully occupied CARRY4
+		end else begin
+
+			// First one
+			if (i == 0) begin
+				CARRY4 #(.IS_INITIALIZED(1'd1)) carry4_1st_full
+				(
+				.CYINIT(CI),
+				.CI    (1'd0),
+				.DI    (DI[((i+1)*4 - 1):i*4]),
+				.S     (S [((i+1)*4 - 1):i*4]),
+				.O     (Y [((i+1)*4 - 1):i*4]),
+				.CO    (CO[((i+1)*4 - 1):i*4])
+				);
+			// Another one
+			end else begin
+				CARRY4 carry4_full
+				(
+				.CYINIT(1'd0),
+				.CI    (C [i*4 - 1]),
+				.DI    (DI[((i+1)*4 - 1):i*4]),
+				.S     (S [((i+1)*4 - 1):i*4]),
+				.O     (Y [((i+1)*4 - 1):i*4]),
+				.CO    (CO[((i+1)*4 - 1):i*4])
+				);
+			end
+
+		end
+
+	end endgenerate
+
+`elsif _EXPLICIT_CARRY
+
+	wire [Y_WIDTH-1:0] S = AA ^ BB;
+	wire [Y_WIDTH-1:0] DI = AA & BB;
+
+	wire CINIT;
+	// Carry chain.
+	//
+	// VPR requires that the carry chain never hit the fabric.	The CO input
+	// to this techmap is the carry outputs for synthesis, e.g. might hit the
+	// fabric.
+	//
+	// So we maintain two wire sets, CO_CHAIN is the carry that is for VPR,
+	// e.g. off fabric dedicated chain.  CO is the carry outputs that are
+	// available to the fabric.
+	wire [Y_WIDTH-1:0] CO_CHAIN;
+	wire [Y_WIDTH-1:0] C = {CO_CHAIN, CINIT};
+
+	// If carry chain is being initialized to a constant, techmap the constant
+	// source.	Otherwise techmap the fabric source.
+	generate for (i = 0; i < 1; i = i + 1) begin:slice
+		CARRY0 #(.CYINIT_FABRIC(1)) carry(
+			.CI_INIT(CI),
+			.DI(DI[0]),
+			.S(S[0]),
+			.CO_CHAIN(CO_CHAIN[0]),
+			.CO_FABRIC(CO[0]),
+			.O(Y[0])
+		);
+	end endgenerate
+
+	generate for (i = 1; i < Y_WIDTH-1; i = i + 1) begin:slice
+		if(i % 4 == 0) begin
+			CARRY0 carry (
+				.CI(C[i]),
+				.DI(DI[i]),
+				.S(S[i]),
+				.CO_CHAIN(CO_CHAIN[i]),
+				.CO_FABRIC(CO[i]),
+				.O(Y[i])
+			);
+		end
+		else
+		begin
+			CARRY carry (
+				.CI(C[i]),
+				.DI(DI[i]),
+				.S(S[i]),
+				.CO_CHAIN(CO_CHAIN[i]),
+				.CO_FABRIC(CO[i]),
+				.O(Y[i])
+			);
+		end
+	end endgenerate
+
+	generate for (i = Y_WIDTH-1; i < Y_WIDTH; i = i + 1) begin:slice
+		if(i % 4 == 0) begin
+			CARRY0 top_of_carry (
+				.CI(C[i]),
+				.DI(DI[i]),
+				.S(S[i]),
+				.CO_CHAIN(CO_CHAIN[i]),
+				.O(Y[i])
+			);
+		end
+		else
+		begin
+			CARRY top_of_carry (
+				.CI(C[i]),
+				.DI(DI[i]),
+				.S(S[i]),
+				.CO_CHAIN(CO_CHAIN[i]),
+				.O(Y[i])
+			);
+		end
+		// Turns out CO_FABRIC and O both use [ABCD]MUX, so provide
+		// a non-congested path to output the top of the carry chain.
+		// Registering the output of the CARRY block would solve this, but not
+		// all designs do that.
+		if((i+1) % 4 == 0) begin
+			CARRY0 carry_output (
+				.CI(CO_CHAIN[i]),
+				.DI(0),
+				.S(0),
+				.O(CO[i])
+			);
+		end
+		else
+		begin
+			CARRY carry_output (
+				.CI(CO_CHAIN[i]),
+				.DI(0),
+				.S(0),
+				.O(CO[i])
+			);
+		end
+	end endgenerate
+
+`else
+
+	wire [Y_WIDTH-1:0] S = AA ^ BB;
+	wire [Y_WIDTH-1:0] DI = AA & BB;
+
+	wire [Y_WIDTH-1:0] C = {CO, CI};
+
 	generate for (i = 0; i < Y_WIDTH; i = i + 1) begin:slice
 		MUXCY muxcy (
 			.CI(C[i]),
-			.DI(G[i]),
+			.DI(DI[i]),
 			.S(S[i]),
 			.O(CO[i])
 		);
@@ -86,6 +352,8 @@ module _80_xilinx_alu (A, B, CI, BI, X, Y, CO);
 		);
 	end endgenerate
 
-	assign X = P;
+`endif
+
+	assign X = S;
 endmodule
 
diff --git a/techlibs/xilinx/cells_map.v b/techlibs/xilinx/cells_map.v
index 0ace369d1..0c5c5a26f 100644
--- a/techlibs/xilinx/cells_map.v
+++ b/techlibs/xilinx/cells_map.v
@@ -1,89 +1,21 @@
-
-module  \$_DFF_N_ (input D, C, output Q); FDRE #(.INIT(|0), .IS_C_INVERTED(|1), .IS_D_INVERTED(|0), .IS_R_INVERTED(|0)) _TECHMAP_REPLACE_ (.D(D), .Q(Q), .C(C), .CE(1'b1), .R(1'b0)); endmodule
-module  \$_DFF_P_ (input D, C, output Q); FDRE #(.INIT(|0), .IS_C_INVERTED(|0), .IS_D_INVERTED(|0), .IS_R_INVERTED(|0)) _TECHMAP_REPLACE_ (.D(D), .Q(Q), .C(C), .CE(1'b1), .R(1'b0)); endmodule
-
-module  \$_DFFE_NP_ (input D, C, E, output Q); FDRE #(.INIT(|0), .IS_C_INVERTED(|1), .IS_D_INVERTED(|0), .IS_R_INVERTED(|0)) _TECHMAP_REPLACE_ (.D(D), .Q(Q), .C(C), .CE(E), .R(1'b0)); endmodule
-module  \$_DFFE_PP_ (input D, C, E, output Q); FDRE #(.INIT(|0), .IS_C_INVERTED(|0), .IS_D_INVERTED(|0), .IS_R_INVERTED(|0)) _TECHMAP_REPLACE_ (.D(D), .Q(Q), .C(C), .CE(E), .R(1'b0)); endmodule
-
-module  \$_DFF_NN0_ (input D, C, R, output Q); FDCE #(.INIT(|0), .IS_C_INVERTED(|1), .IS_D_INVERTED(|0), .IS_CLR_INVERTED(|1)) _TECHMAP_REPLACE_ (.D(D), .Q(Q), .C(C), .CE(1'b1), .CLR(R)); endmodule
-module  \$_DFF_NP0_ (input D, C, R, output Q); FDCE #(.INIT(|0), .IS_C_INVERTED(|1), .IS_D_INVERTED(|0), .IS_CLR_INVERTED(|0)) _TECHMAP_REPLACE_ (.D(D), .Q(Q), .C(C), .CE(1'b1), .CLR(R)); endmodule
-module  \$_DFF_PN0_ (input D, C, R, output Q); FDCE #(.INIT(|0), .IS_C_INVERTED(|0), .IS_D_INVERTED(|0), .IS_CLR_INVERTED(|1)) _TECHMAP_REPLACE_ (.D(D), .Q(Q), .C(C), .CE(1'b1), .CLR(R)); endmodule
-module  \$_DFF_PP0_ (input D, C, R, output Q); FDCE #(.INIT(|0), .IS_C_INVERTED(|0), .IS_D_INVERTED(|0), .IS_CLR_INVERTED(|0)) _TECHMAP_REPLACE_ (.D(D), .Q(Q), .C(C), .CE(1'b1), .CLR(R)); endmodule
-
-module  \$_DFF_NN1_ (input D, C, R, output Q); FDPE #(.INIT(|0), .IS_C_INVERTED(|1), .IS_D_INVERTED(|0), .IS_PRE_INVERTED(|1)) _TECHMAP_REPLACE_ (.D(D), .Q(Q), .C(C), .CE(1'b1), .PRE(R)); endmodule
-module  \$_DFF_NP1_ (input D, C, R, output Q); FDPE #(.INIT(|0), .IS_C_INVERTED(|1), .IS_D_INVERTED(|0), .IS_PRE_INVERTED(|0)) _TECHMAP_REPLACE_ (.D(D), .Q(Q), .C(C), .CE(1'b1), .PRE(R)); endmodule
-module  \$_DFF_PN1_ (input D, C, R, output Q); FDPE #(.INIT(|0), .IS_C_INVERTED(|0), .IS_D_INVERTED(|0), .IS_PRE_INVERTED(|1)) _TECHMAP_REPLACE_ (.D(D), .Q(Q), .C(C), .CE(1'b1), .PRE(R)); endmodule
-module  \$_DFF_PP1_ (input D, C, R, output Q); FDPE #(.INIT(|0), .IS_C_INVERTED(|0), .IS_D_INVERTED(|0), .IS_PRE_INVERTED(|0)) _TECHMAP_REPLACE_ (.D(D), .Q(Q), .C(C), .CE(1'b1), .PRE(R)); endmodule
-
-`ifndef NO_LUT
-module \$lut (A, Y);
-  parameter WIDTH = 0;
-  parameter LUT = 0;
-
-  input [WIDTH-1:0] A;
-  output Y;
-
-  generate
-    if (WIDTH == 1) begin
-      LUT1 #(.INIT(LUT)) _TECHMAP_REPLACE_ (.O(Y),
-        .I0(A[0]));
-    end else
-    if (WIDTH == 2) begin
-      LUT2 #(.INIT(LUT)) _TECHMAP_REPLACE_ (.O(Y),
-        .I0(A[0]), .I1(A[1]));
-    end else
-    if (WIDTH == 3) begin
-      LUT3 #(.INIT(LUT)) _TECHMAP_REPLACE_ (.O(Y),
-        .I0(A[0]), .I1(A[1]), .I2(A[2]));
-    end else
-    if (WIDTH == 4) begin
-      LUT4 #(.INIT(LUT)) _TECHMAP_REPLACE_ (.O(Y),
-        .I0(A[0]), .I1(A[1]), .I2(A[2]),
-        .I3(A[3]));
-    end else
-    if (WIDTH == 5) begin
-      LUT5 #(.INIT(LUT)) _TECHMAP_REPLACE_ (.O(Y),
-        .I0(A[0]), .I1(A[1]), .I2(A[2]),
-        .I3(A[3]), .I4(A[4]));
-    end else
-    if (WIDTH == 6) begin
-      LUT6 #(.INIT(LUT)) _TECHMAP_REPLACE_ (.O(Y),
-        .I0(A[0]), .I1(A[1]), .I2(A[2]),
-        .I3(A[3]), .I4(A[4]), .I5(A[5]));
-    end else
-    if (WIDTH == 7) begin
-      wire T0, T1;
-      LUT6 #(.INIT(LUT[63:0])) fpga_lut_0 (.O(T0),
-        .I0(A[0]), .I1(A[1]), .I2(A[2]),
-        .I3(A[3]), .I4(A[4]), .I5(A[5]));
-      LUT6 #(.INIT(LUT[127:64])) fpga_lut_1 (.O(T1),
-        .I0(A[0]), .I1(A[1]), .I2(A[2]),
-        .I3(A[3]), .I4(A[4]), .I5(A[5]));
-      MUXF7 fpga_mux_0 (.O(Y), .I0(T0), .I1(T1), .S(A[6]));
-    end else
-    if (WIDTH == 8) begin
-      wire T0, T1, T2, T3, T4, T5;
-      LUT6 #(.INIT(LUT[63:0])) fpga_lut_0 (.O(T0),
-        .I0(A[0]), .I1(A[1]), .I2(A[2]),
-        .I3(A[3]), .I4(A[4]), .I5(A[5]));
-      LUT6 #(.INIT(LUT[127:64])) fpga_lut_1 (.O(T1),
-        .I0(A[0]), .I1(A[1]), .I2(A[2]),
-        .I3(A[3]), .I4(A[4]), .I5(A[5]));
-      LUT6 #(.INIT(LUT[191:128])) fpga_lut_2 (.O(T2),
-        .I0(A[0]), .I1(A[1]), .I2(A[2]),
-        .I3(A[3]), .I4(A[4]), .I5(A[5]));
-      LUT6 #(.INIT(LUT[255:192])) fpga_lut_3 (.O(T3),
-        .I0(A[0]), .I1(A[1]), .I2(A[2]),
-        .I3(A[3]), .I4(A[4]), .I5(A[5]));
-      MUXF7 fpga_mux_0 (.O(T4), .I0(T0), .I1(T1), .S(A[6]));
-      MUXF7 fpga_mux_1 (.O(T5), .I0(T2), .I1(T3), .S(A[6]));
-      MUXF8 fpga_mux_2 (.O(Y), .I0(T4), .I1(T5), .S(A[7]));
-    end else begin
-      wire _TECHMAP_FAIL_ = 1;
-    end
-  endgenerate
-endmodule
-`endif
+/*
+ *  yosys -- Yosys Open SYnthesis Suite
+ *
+ *  Copyright (C) 2012  Clifford Wolf <clifford@clifford.at>
+ *
+ *  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.
+ *
+ */
 
 module \$__SHREG_ (input C, input D, input E, output Q);
   parameter DEPTH = 0;
diff --git a/techlibs/xilinx/cells_sim.v b/techlibs/xilinx/cells_sim.v
index 68f678385..c756115f6 100644
--- a/techlibs/xilinx/cells_sim.v
+++ b/techlibs/xilinx/cells_sim.v
@@ -1,3 +1,21 @@
+/*
+ *  yosys -- Yosys Open SYnthesis Suite
+ *
+ *  Copyright (C) 2012  Clifford Wolf <clifford@clifford.at>
+ *
+ *  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.
+ *
+ */
 
 // See Xilinx UG953 and UG474 for a description of the cell types below.
 // http://www.xilinx.com/support/documentation/user_guides/ug474_7Series_CLB.pdf
@@ -104,6 +122,29 @@ module CARRY4(output [3:0] CO, O, input CI, CYINIT, input [3:0] DI, S);
   assign CO[3] = S[3] ? CO[2] : DI[3];
 endmodule
 
+`ifdef _EXPLICIT_CARRY
+
+module CARRY0(output CO_CHAIN, CO_FABRIC, O, input CI, CI_INIT, DI, S);
+  parameter CYINIT_FABRIC = 0;
+  wire CI_COMBINE;
+  if(CYINIT_FABRIC) begin
+    assign CI_COMBINE = CI_INIT;
+  end else begin
+    assign CI_COMBINE = CI;
+  end
+  assign CO_CHAIN = S ? CI_COMBINE : DI;
+  assign CO_FABRIC = S ? CI_COMBINE : DI;
+  assign O = S ^ CI_COMBINE;
+endmodule
+
+module CARRY(output CO_CHAIN, CO_FABRIC, O, input CI, DI, S);
+  assign CO_CHAIN = S ? CI : DI;
+  assign CO_FABRIC = S ? CI : DI;
+  assign O = S ^ CI;
+endmodule
+
+`endif
+
 module FDRE (output reg Q, input C, CE, D, R);
   parameter [0:0] INIT = 1'b0;
   parameter [0:0] IS_C_INVERTED = 1'b0;
@@ -156,6 +197,30 @@ module FDPE (output reg Q, input C, CE, D, PRE);
   endcase endgenerate
 endmodule
 
+module FDRE_1 (output reg Q, input C, CE, D, R);
+  parameter [0:0] INIT = 1'b0;
+  initial Q <= INIT;
+  always @(negedge C) if (R) Q <= 1'b0; else if(CE) Q <= D;
+endmodule
+
+module FDSE_1 (output reg Q, input C, CE, D, S);
+  parameter [0:0] INIT = 1'b1;
+  initial Q <= INIT;
+  always @(negedge C) if (S) Q <= 1'b1; else if(CE) Q <= D;
+endmodule
+
+module FDCE_1 (output reg Q, input C, CE, D, CLR);
+  parameter [0:0] INIT = 1'b0;
+  initial Q <= INIT;
+  always @(negedge C, posedge CLR) if (CLR) Q <= 1'b0; else if (CE) Q <= D;
+endmodule
+
+module FDPE_1 (output reg Q, input C, CE, D, PRE);
+  parameter [0:0] INIT = 1'b1;
+  initial Q <= INIT;
+  always @(negedge C, posedge PRE) if (PRE) Q <= 1'b1; else if (CE) Q <= D;
+endmodule
+
 module RAM64X1D (
   output DPO, SPO,
   input  D, WCLK, WE,
diff --git a/techlibs/xilinx/cells_xtra.sh b/techlibs/xilinx/cells_xtra.sh
index 8cc90d1f2..46ababdea 100644
--- a/techlibs/xilinx/cells_xtra.sh
+++ b/techlibs/xilinx/cells_xtra.sh
@@ -115,7 +115,7 @@ function xtract_cell_decl()
 	xtract_cell_decl PS7
 	xtract_cell_decl PULLDOWN
 	xtract_cell_decl PULLUP
-	# xtract_cell_decl RAM128X1D
+	xtract_cell_decl RAM128X1D
 	xtract_cell_decl RAM128X1S
 	xtract_cell_decl RAM256X1S
 	xtract_cell_decl RAM32M
@@ -124,7 +124,7 @@ function xtract_cell_decl()
 	xtract_cell_decl RAM32X1S_1
 	xtract_cell_decl RAM32X2S
 	xtract_cell_decl RAM64M
-	# xtract_cell_decl RAM64X1D
+	xtract_cell_decl RAM64X1D
 	xtract_cell_decl RAM64X1S
 	xtract_cell_decl RAM64X1S_1
 	xtract_cell_decl RAM64X2S
diff --git a/techlibs/xilinx/cells_xtra.v b/techlibs/xilinx/cells_xtra.v
index 21db6a6bd..6adad35ae 100644
--- a/techlibs/xilinx/cells_xtra.v
+++ b/techlibs/xilinx/cells_xtra.v
@@ -3695,6 +3695,25 @@ module RAM128X1S (...);
     input A0, A1, A2, A3, A4, A5, A6, D, WCLK, WE;
 endmodule
 
+module RAM128X1D (
+  output       DPO, SPO,
+  input        D, WCLK, WE,
+  input  [6:0] A, DPRA
+);
+	parameter [127:0] INIT = 128'bx;
+	parameter IS_WCLK_INVERTED = 0;
+endmodule
+
+module RAM64X1D (
+  output DPO, SPO,
+  input  D, WCLK, WE,
+  input  A0, A1, A2, A3, A4, A5,
+  input  DPRA0, DPRA1, DPRA2, DPRA3, DPRA4, DPRA5
+);
+	parameter [63:0] INIT = 64'bx;
+	parameter IS_WCLK_INVERTED = 0;
+endmodule
+
 module RAM256X1S (...);
     parameter [255:0] INIT = 256'h0;
     parameter [0:0] IS_WCLK_INVERTED = 1'b0;
diff --git a/techlibs/xilinx/ff_map.v b/techlibs/xilinx/ff_map.v
new file mode 100644
index 000000000..13beaa6ae
--- /dev/null
+++ b/techlibs/xilinx/ff_map.v
@@ -0,0 +1,42 @@
+/*
+ *  yosys -- Yosys Open SYnthesis Suite
+ *
+ *  Copyright (C) 2012  Clifford Wolf <clifford@clifford.at>
+ *
+ *  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.
+ *
+ */
+
+// ============================================================================
+// FF mapping
+
+`ifndef _NO_FFS
+
+module  \$_DFF_N_   (input D, C, output Q);    FDRE_1 #(.INIT(|0)) _TECHMAP_REPLACE_ (.D(D), .Q(Q), .C(C), .CE(1'b1), .R(1'b0)); endmodule
+module  \$_DFF_P_   (input D, C, output Q);    FDRE   #(.INIT(|0)) _TECHMAP_REPLACE_ (.D(D), .Q(Q), .C(C), .CE(1'b1), .R(1'b0)); endmodule
+
+module  \$_DFFE_NP_ (input D, C, E, output Q); FDRE_1 #(.INIT(|0)) _TECHMAP_REPLACE_ (.D(D), .Q(Q), .C(C), .CE(E),    .R(1'b0)); endmodule
+module  \$_DFFE_PP_ (input D, C, E, output Q); FDRE   #(.INIT(|0)) _TECHMAP_REPLACE_ (.D(D), .Q(Q), .C(C), .CE(E),    .R(1'b0)); endmodule
+
+module  \$_DFF_NN0_ (input D, C, R, output Q); FDCE_1 #(.INIT(|0)) _TECHMAP_REPLACE_ (.D(D), .Q(Q), .C(C), .CE(1'b1), .CLR(!R)); endmodule
+module  \$_DFF_NP0_ (input D, C, R, output Q); FDCE_1 #(.INIT(|0)) _TECHMAP_REPLACE_ (.D(D), .Q(Q), .C(C), .CE(1'b1), .CLR( R)); endmodule
+module  \$_DFF_PN0_ (input D, C, R, output Q); FDCE   #(.INIT(|0)) _TECHMAP_REPLACE_ (.D(D), .Q(Q), .C(C), .CE(1'b1), .CLR(!R)); endmodule
+module  \$_DFF_PP0_ (input D, C, R, output Q); FDCE   #(.INIT(|0)) _TECHMAP_REPLACE_ (.D(D), .Q(Q), .C(C), .CE(1'b1), .CLR( R)); endmodule
+
+module  \$_DFF_NN1_ (input D, C, R, output Q); FDPE_1 #(.INIT(|0)) _TECHMAP_REPLACE_ (.D(D), .Q(Q), .C(C), .CE(1'b1), .PRE(!R)); endmodule
+module  \$_DFF_NP1_ (input D, C, R, output Q); FDPE_1 #(.INIT(|0)) _TECHMAP_REPLACE_ (.D(D), .Q(Q), .C(C), .CE(1'b1), .PRE( R)); endmodule
+module  \$_DFF_PN1_ (input D, C, R, output Q); FDPE   #(.INIT(|0)) _TECHMAP_REPLACE_ (.D(D), .Q(Q), .C(C), .CE(1'b1), .PRE(!R)); endmodule
+module  \$_DFF_PP1_ (input D, C, R, output Q); FDPE   #(.INIT(|0)) _TECHMAP_REPLACE_ (.D(D), .Q(Q), .C(C), .CE(1'b1), .PRE( R)); endmodule
+
+`endif
+
diff --git a/techlibs/xilinx/lut2lut.v b/techlibs/xilinx/lut2lut.v
deleted file mode 100644
index 061ad2041..000000000
--- a/techlibs/xilinx/lut2lut.v
+++ /dev/null
@@ -1,65 +0,0 @@
-module LUT1(output O, input I0);
-  parameter [1:0] INIT = 0;
-  \$lut #(
-    .WIDTH(1),
-    .LUT(INIT)
-  ) _TECHMAP_REPLACE_ (
-    .A(I0),
-    .Y(O)
-  );
-endmodule
-
-module LUT2(output O, input I0, I1);
-  parameter [3:0] INIT = 0;
-  \$lut #(
-    .WIDTH(2),
-    .LUT(INIT)
-  ) _TECHMAP_REPLACE_ (
-    .A({I1, I0}),
-    .Y(O)
-  );
-endmodule
-
-module LUT3(output O, input I0, I1, I2);
-  parameter [7:0] INIT = 0;
-  \$lut #(
-    .WIDTH(3),
-    .LUT(INIT)
-  ) _TECHMAP_REPLACE_ (
-    .A({I2, I1, I0}),
-    .Y(O)
-  );
-endmodule
-
-module LUT4(output O, input I0, I1, I2, I3);
-  parameter [15:0] INIT = 0;
-  \$lut #(
-    .WIDTH(4),
-    .LUT(INIT)
-  ) _TECHMAP_REPLACE_ (
-    .A({I3, I2, I1, I0}),
-    .Y(O)
-  );
-endmodule
-
-module LUT5(output O, input I0, I1, I2, I3, I4);
-  parameter [31:0] INIT = 0;
-  \$lut #(
-    .WIDTH(5),
-    .LUT(INIT)
-  ) _TECHMAP_REPLACE_ (
-    .A({I4, I3, I2, I1, I0}),
-    .Y(O)
-  );
-endmodule
-
-module LUT6(output O, input I0, I1, I2, I3, I4, I5);
-  parameter [63:0] INIT = 0;
-  \$lut #(
-    .WIDTH(6),
-    .LUT(INIT)
-  ) _TECHMAP_REPLACE_ (
-    .A({I5, I4, I3, I2, I1, I0}),
-    .Y(O)
-  );
-endmodule
diff --git a/techlibs/xilinx/lut_map.v b/techlibs/xilinx/lut_map.v
new file mode 100644
index 000000000..d07c59dee
--- /dev/null
+++ b/techlibs/xilinx/lut_map.v
@@ -0,0 +1,94 @@
+/*
+ *  yosys -- Yosys Open SYnthesis Suite
+ *
+ *  Copyright (C) 2012  Clifford Wolf <clifford@clifford.at>
+ *
+ *  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.
+ *
+ */
+
+// ============================================================================
+// LUT mapping
+
+`ifndef _NO_LUTS
+
+module \$lut (A, Y);
+  parameter WIDTH = 0;
+  parameter LUT = 0;
+
+  input [WIDTH-1:0] A;
+  output Y;
+
+  generate
+    if (WIDTH == 1) begin
+      LUT1 #(.INIT(LUT)) _TECHMAP_REPLACE_ (.O(Y),
+        .I0(A[0]));
+    end else
+    if (WIDTH == 2) begin
+      LUT2 #(.INIT(LUT)) _TECHMAP_REPLACE_ (.O(Y),
+        .I0(A[0]), .I1(A[1]));
+    end else
+    if (WIDTH == 3) begin
+      LUT3 #(.INIT(LUT)) _TECHMAP_REPLACE_ (.O(Y),
+        .I0(A[0]), .I1(A[1]), .I2(A[2]));
+    end else
+    if (WIDTH == 4) begin
+      LUT4 #(.INIT(LUT)) _TECHMAP_REPLACE_ (.O(Y),
+        .I0(A[0]), .I1(A[1]), .I2(A[2]),
+        .I3(A[3]));
+    end else
+    if (WIDTH == 5) begin
+      LUT5 #(.INIT(LUT)) _TECHMAP_REPLACE_ (.O(Y),
+        .I0(A[0]), .I1(A[1]), .I2(A[2]),
+        .I3(A[3]), .I4(A[4]));
+    end else
+    if (WIDTH == 6) begin
+      LUT6 #(.INIT(LUT)) _TECHMAP_REPLACE_ (.O(Y),
+        .I0(A[0]), .I1(A[1]), .I2(A[2]),
+        .I3(A[3]), .I4(A[4]), .I5(A[5]));
+    end else
+    if (WIDTH == 7) begin
+      wire T0, T1;
+      LUT6 #(.INIT(LUT[63:0])) fpga_lut_0 (.O(T0),
+        .I0(A[0]), .I1(A[1]), .I2(A[2]),
+        .I3(A[3]), .I4(A[4]), .I5(A[5]));
+      LUT6 #(.INIT(LUT[127:64])) fpga_lut_1 (.O(T1),
+        .I0(A[0]), .I1(A[1]), .I2(A[2]),
+        .I3(A[3]), .I4(A[4]), .I5(A[5]));
+      MUXF7 fpga_mux_0 (.O(Y), .I0(T0), .I1(T1), .S(A[6]));
+    end else
+    if (WIDTH == 8) begin
+      wire T0, T1, T2, T3, T4, T5;
+      LUT6 #(.INIT(LUT[63:0])) fpga_lut_0 (.O(T0),
+        .I0(A[0]), .I1(A[1]), .I2(A[2]),
+        .I3(A[3]), .I4(A[4]), .I5(A[5]));
+      LUT6 #(.INIT(LUT[127:64])) fpga_lut_1 (.O(T1),
+        .I0(A[0]), .I1(A[1]), .I2(A[2]),
+        .I3(A[3]), .I4(A[4]), .I5(A[5]));
+      LUT6 #(.INIT(LUT[191:128])) fpga_lut_2 (.O(T2),
+        .I0(A[0]), .I1(A[1]), .I2(A[2]),
+        .I3(A[3]), .I4(A[4]), .I5(A[5]));
+      LUT6 #(.INIT(LUT[255:192])) fpga_lut_3 (.O(T3),
+        .I0(A[0]), .I1(A[1]), .I2(A[2]),
+        .I3(A[3]), .I4(A[4]), .I5(A[5]));
+      MUXF7 fpga_mux_0 (.O(T4), .I0(T0), .I1(T1), .S(A[6]));
+      MUXF7 fpga_mux_1 (.O(T5), .I0(T2), .I1(T3), .S(A[6]));
+      MUXF8 fpga_mux_2 (.O(Y), .I0(T4), .I1(T5), .S(A[7]));
+    end else begin
+      wire _TECHMAP_FAIL_ = 1;
+    end
+  endgenerate
+endmodule
+
+`endif
+
diff --git a/techlibs/xilinx/synth_xilinx.cc b/techlibs/xilinx/synth_xilinx.cc
index 71b468e38..169f3b7ce 100644
--- a/techlibs/xilinx/synth_xilinx.cc
+++ b/techlibs/xilinx/synth_xilinx.cc
@@ -63,6 +63,12 @@ struct SynthXilinxPass : public Pass
 		log("        generate an output netlist (and BLIF file) suitable for VPR\n");
 		log("        (this feature is experimental and incomplete)\n");
 		log("\n");
+		log("    -nobram\n");
+		log("        disable infering of block rams\n");
+		log("\n");
+		log("    -nodram\n");
+		log("        disable infering of distributed rams\n");
+		log("\n");
 		log("    -run <from_label>:<to_label>\n");
 		log("        only run the commands between the labels (see below). an empty\n");
 		log("        from label is synonymous to 'begin', and empty to label is\n");
@@ -90,11 +96,11 @@ struct SynthXilinxPass : public Pass
 		log("    coarse:\n");
 		log("        synth -run coarse\n");
 		log("\n");
-		log("    bram:\n");
+		log("    bram: (only executed when '-nobram' is not given)\n");
 		log("        memory_bram -rules +/xilinx/brams.txt\n");
 		log("        techmap -map +/xilinx/brams_map.v\n");
 		log("\n");
-		log("    dram:\n");
+		log("    dram: (only executed when '-nodram' is not given)\n");
 		log("        memory_bram -rules +/xilinx/drams.txt\n");
 		log("        techmap -map +/xilinx/drams_map.v\n");
 		log("\n");
@@ -106,15 +112,17 @@ struct SynthXilinxPass : public Pass
 		log("        opt -full\n");
 		log("        techmap -map +/techmap.v -map +/xilinx/arith_map.v\n");
 		log("        shregmap -init_msb_first -params -enpol any_or_none\n");
+		log("        techmap -map +/xilinx/ff_map.v\n");
 		log("        opt -fast\n");
 		log("\n");
 		log("    map_luts:\n");
-		log("        abc -luts 2:2,3,6:5,10,20 [-dff]\n");
+		log("        abc -luts 2:2,3,6:5,10,20 [-dff] (without '-vpr' only!)\n");
+		log("        abc -lut 5 [-dff] (with '-vpr' only!)\n");
 		log("        clean\n");
 		log("\n");
 		log("    map_cells:\n");
-		log("        techmap -map +/xilinx/cells_map.v (with -D NO_LUT in vpr mode)\n");
-		log("        dffinit -ff FDRE Q INIT -ff FDCE Q INIT -ff FDPE Q INIT\n");
+		log("        techmap -map +/xilinx/cells_map.v\n");
+		log("        dffinit -ff FDRE Q INIT -ff FDCE Q INIT -ff FDPE Q INIT -ff FDSE Q INIT\n");
 		log("        clean\n");
 		log("\n");
 		log("    check:\n");
@@ -138,6 +146,8 @@ struct SynthXilinxPass : public Pass
 		bool flatten = false;
 		bool retime = false;
 		bool vpr = false;
+		bool nobram = false;
+		bool nodram = false;
 
 		size_t argidx;
 		for (argidx = 1; argidx < args.size(); argidx++)
@@ -174,6 +184,14 @@ struct SynthXilinxPass : public Pass
 				vpr = true;
 				continue;
 			}
+			if (args[argidx] == "-nobram") {
+				nobram = true;
+				continue;
+			}
+			if (args[argidx] == "-nodram") {
+				nodram = true;
+				continue;
+			}
 			break;
 		}
 		extra_args(args, argidx, design);
@@ -188,9 +206,18 @@ struct SynthXilinxPass : public Pass
 
 		if (check_label(active, run_from, run_to, "begin"))
 		{
-			Pass::call(design, "read_verilog -lib +/xilinx/cells_sim.v");
+			if (vpr) {
+				Pass::call(design, "read_verilog -lib -D_EXPLICIT_CARRY +/xilinx/cells_sim.v");
+			} else {
+				Pass::call(design, "read_verilog -lib +/xilinx/cells_sim.v");
+			}
+
 			Pass::call(design, "read_verilog -lib +/xilinx/cells_xtra.v");
-			Pass::call(design, "read_verilog -lib +/xilinx/brams_bb.v");
+
+			if (!nobram) {
+				Pass::call(design, "read_verilog -lib +/xilinx/brams_bb.v");
+			}
+
 			Pass::call(design, stringf("hierarchy -check %s", top_opt.c_str()));
 		}
 
@@ -207,14 +234,18 @@ struct SynthXilinxPass : public Pass
 
 		if (check_label(active, run_from, run_to, "bram"))
 		{
-			Pass::call(design, "memory_bram -rules +/xilinx/brams.txt");
-			Pass::call(design, "techmap -map +/xilinx/brams_map.v");
+			if (!nobram) {
+				Pass::call(design, "memory_bram -rules +/xilinx/brams.txt");
+				Pass::call(design, "techmap -map +/xilinx/brams_map.v");
+			}
 		}
 
 		if (check_label(active, run_from, run_to, "dram"))
 		{
-			Pass::call(design, "memory_bram -rules +/xilinx/drams.txt");
-			Pass::call(design, "techmap -map +/xilinx/drams_map.v");
+			if (!nodram) {
+				Pass::call(design, "memory_bram -rules +/xilinx/drams.txt");
+				Pass::call(design, "techmap -map +/xilinx/drams_map.v");
+			}
 		}
 
 		if (check_label(active, run_from, run_to, "fine"))
@@ -224,8 +255,16 @@ struct SynthXilinxPass : public Pass
 			Pass::call(design, "dffsr2dff");
 			Pass::call(design, "dff2dffe");
 			Pass::call(design, "opt -full");
-			Pass::call(design, "techmap -map +/techmap.v -map +/xilinx/arith_map.v");
+
+			if (vpr) {
+				Pass::call(design, "techmap -map +/techmap.v -map +/xilinx/arith_map.v -D _EXPLICIT_CARRY");
+			} else {
+				Pass::call(design, "techmap -map +/techmap.v -map +/xilinx/arith_map.v");
+			}
+
 			Pass::call(design, "shregmap -init_msb_first -params -enpol any_or_none");
+			Pass::call(design, "techmap -map +/xilinx/ff_map.v");
+			Pass::call(design, "hierarchy -check");
 			Pass::call(design, "opt -fast");
 		}
 
@@ -233,14 +272,13 @@ struct SynthXilinxPass : public Pass
 		{
 			Pass::call(design, "abc -luts 2:2,3,6:5,10,20" + string(retime ? " -dff" : ""));
 			Pass::call(design, "clean");
+			Pass::call(design, "techmap -map +/xilinx/lut_map.v");
 		}
 
 		if (check_label(active, run_from, run_to, "map_cells"))
 		{
 			Pass::call(design, "techmap -map +/xilinx/cells_map.v");
-			if (vpr)
-			    Pass::call(design, "techmap -map +/xilinx/lut2lut.v");
-			Pass::call(design, "dffinit -ff FDRE Q INIT -ff FDCE Q INIT -ff FDPE Q INIT");
+			Pass::call(design, "dffinit -ff FDRE Q INIT -ff FDCE Q INIT -ff FDPE Q INIT -ff FDSE Q INIT");
 			Pass::call(design, "clean");
 		}
 
@@ -254,7 +292,7 @@ struct SynthXilinxPass : public Pass
 		if (check_label(active, run_from, run_to, "edif"))
 		{
 			if (!edif_file.empty())
-				Pass::call(design, stringf("write_edif %s", edif_file.c_str()));
+				Pass::call(design, stringf("write_edif -pvector bra %s", edif_file.c_str()));
 		}
 		if (check_label(active, run_from, run_to, "blif"))
 		{