ecp5: Add GSR support

Signed-off-by: David Shah <dave@ds0.me>

6 files changed, 212 insertions, 54 deletions

diff --git a/techlibs/ecp5/Makefile.inc b/techlibs/ecp5/Makefile.inc
index 73e18112f..c41d16076 100644
--- a/techlibs/ecp5/Makefile.inc
+++ b/techlibs/ecp5/Makefile.inc
@@ -1,5 +1,6 @@
 
-OBJS += techlibs/ecp5/synth_ecp5.o techlibs/ecp5/ecp5_ffinit.o
+OBJS += techlibs/ecp5/synth_ecp5.o techlibs/ecp5/ecp5_ffinit.o \
+        techlibs/ecp5/ecp5_gsr.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/brams_map.v b/techlibs/ecp5/brams_map.v
index b2c136863..0353cbadb 100644
--- a/techlibs/ecp5/brams_map.v
+++ b/techlibs/ecp5/brams_map.v
@@ -33,7 +33,7 @@ module \$__ECP5_DP16KD (CLK2, CLK3, A1ADDR, A1DATA, A1EN, B1ADDR, B1DATA, B1EN);
 			.CLKBMUX(CLKBMUX),
 			.WRITEMODE_A(WRITEMODE_A),
 			.WRITEMODE_B("READBEFOREWRITE"),
-			.GSR("DISABLED")
+			.GSR("AUTO")
 		) _TECHMAP_REPLACE_ (
 			`include "bram_conn_1.vh"
 			.CLKA(CLK2), .CLKB(CLK3),
@@ -50,7 +50,7 @@ module \$__ECP5_DP16KD (CLK2, CLK3, A1ADDR, A1DATA, A1EN, B1ADDR, B1DATA, B1EN);
 			.CLKBMUX(CLKBMUX),
 			.WRITEMODE_A(WRITEMODE_A),
 			.WRITEMODE_B("READBEFOREWRITE"),
-			.GSR("DISABLED")
+			.GSR("AUTO")
 		) _TECHMAP_REPLACE_ (
 			`include "bram_conn_2.vh"
 			.CLKA(CLK2), .CLKB(CLK3),
@@ -67,7 +67,7 @@ module \$__ECP5_DP16KD (CLK2, CLK3, A1ADDR, A1DATA, A1EN, B1ADDR, B1DATA, B1EN);
 			.CLKBMUX(CLKBMUX),
 			.WRITEMODE_A(WRITEMODE_A),
 			.WRITEMODE_B("READBEFOREWRITE"),
-			.GSR("DISABLED")
+			.GSR("AUTO")
 		) _TECHMAP_REPLACE_ (
 			`include "bram_conn_4.vh"
 			.CLKA(CLK2), .CLKB(CLK3),
@@ -84,7 +84,7 @@ module \$__ECP5_DP16KD (CLK2, CLK3, A1ADDR, A1DATA, A1EN, B1ADDR, B1DATA, B1EN);
 			.CLKBMUX(CLKBMUX),
 			.WRITEMODE_A(WRITEMODE_A),
 			.WRITEMODE_B("READBEFOREWRITE"),
-			.GSR("DISABLED")
+			.GSR("AUTO")
 		) _TECHMAP_REPLACE_ (
 			`include "bram_conn_9.vh"
 			.CLKA(CLK2), .CLKB(CLK3),
@@ -101,7 +101,7 @@ module \$__ECP5_DP16KD (CLK2, CLK3, A1ADDR, A1DATA, A1EN, B1ADDR, B1DATA, B1EN);
 			.CLKBMUX(CLKBMUX),
 			.WRITEMODE_A(WRITEMODE_A),
 			.WRITEMODE_B("READBEFOREWRITE"),
-			.GSR("DISABLED")
+			.GSR("AUTO")
 		) _TECHMAP_REPLACE_ (
 			`include "bram_conn_18.vh"
 			.CLKA(CLK2), .CLKB(CLK3),
diff --git a/techlibs/ecp5/cells_bb.v b/techlibs/ecp5/cells_bb.v
index 223e19b9e..8557053b6 100644
--- a/techlibs/ecp5/cells_bb.v
+++ b/techlibs/ecp5/cells_bb.v
@@ -664,3 +664,23 @@ module PCSCLKDIV (
 );
 	parameter GSR = "DISABLED";
 endmodule
+
+// Note: this module is not marked keep as we want it swept away in synth (sim use only)
+(* blackbox *)
+module PUR (
+	input PUR
+);
+	parameter RST_PULSE = 1;
+endmodule
+
+(* blackbox, keep *)
+module GSR (
+	input GSR
+);
+endmodule
+
+(* blackbox, keep *)
+module SGSR (
+	input GSR, CLK
+);
+endmodule
\ No newline at end of file
diff --git a/techlibs/ecp5/cells_map.v b/techlibs/ecp5/cells_map.v
index 6985fbbc8..0a92d906d 100644
--- a/techlibs/ecp5/cells_map.v
+++ b/techlibs/ecp5/cells_map.v
@@ -1,51 +1,51 @@
-module  \$_DFF_N_ (input D, C, output Q); TRELLIS_FF #(.GSR("DISABLED"), .CEMUX("1"), .CLKMUX("INV"), .LSRMUX("LSR"), .REGSET("RESET"))  _TECHMAP_REPLACE_ (.CLK(C), .LSR(1'b0), .DI(D), .Q(Q)); endmodule
-module  \$_DFF_P_ (input D, C, output Q); TRELLIS_FF #(.GSR("DISABLED"), .CEMUX("1"), .CLKMUX("CLK"), .LSRMUX("LSR"), .REGSET("RESET"))  _TECHMAP_REPLACE_ (.CLK(C), .LSR(1'b0), .DI(D), .Q(Q)); endmodule
-
-module  \$_DFFE_NN_ (input D, C, E, output Q); TRELLIS_FF #(.GSR("DISABLED"), .CEMUX("INV"), .CLKMUX("INV"), .LSRMUX("LSR"), .REGSET("RESET"))  _TECHMAP_REPLACE_ (.CLK(C), .CE(E), .LSR(1'b0), .DI(D), .Q(Q)); endmodule
-module  \$_DFFE_PN_ (input D, C, E, output Q); TRELLIS_FF #(.GSR("DISABLED"), .CEMUX("INV"), .CLKMUX("CLK"), .LSRMUX("LSR"), .REGSET("RESET"))  _TECHMAP_REPLACE_ (.CLK(C), .CE(E), .LSR(1'b0), .DI(D), .Q(Q)); endmodule
-
-module  \$_DFFE_NP_ (input D, C, E, output Q); TRELLIS_FF #(.GSR("DISABLED"), .CEMUX("CE"), .CLKMUX("INV"), .LSRMUX("LSR"), .REGSET("RESET"))  _TECHMAP_REPLACE_ (.CLK(C), .CE(E), .LSR(1'b0), .DI(D), .Q(Q)); endmodule
-module  \$_DFFE_PP_ (input D, C, E, output Q); TRELLIS_FF #(.GSR("DISABLED"), .CEMUX("CE"), .CLKMUX("CLK"), .LSRMUX("LSR"), .REGSET("RESET"))  _TECHMAP_REPLACE_ (.CLK(C), .CE(E), .LSR(1'b0), .DI(D), .Q(Q)); endmodule
-
-module  \$_DFF_NN0_ (input D, C, R, output Q); TRELLIS_FF #(.GSR("DISABLED"), .CEMUX("1"), .CLKMUX("INV"), .LSRMUX("LSR"), .REGSET("RESET"), .SRMODE("ASYNC"))  _TECHMAP_REPLACE_ (.CLK(C), .LSR(!R), .DI(D), .Q(Q)); endmodule
-module  \$_DFF_NN1_ (input D, C, R, output Q); TRELLIS_FF #(.GSR("DISABLED"), .CEMUX("1"), .CLKMUX("INV"), .LSRMUX("LSR"), .REGSET("SET"), .SRMODE("ASYNC"))  _TECHMAP_REPLACE_ (.CLK(C), .LSR(!R), .DI(D), .Q(Q)); endmodule
-module  \$_DFF_PN0_ (input D, C, R, output Q); TRELLIS_FF #(.GSR("DISABLED"), .CEMUX("1"), .CLKMUX("CLK"), .LSRMUX("LSR"), .REGSET("RESET"), .SRMODE("ASYNC"))  _TECHMAP_REPLACE_ (.CLK(C), .LSR(!R), .DI(D), .Q(Q)); endmodule
-module  \$_DFF_PN1_ (input D, C, R, output Q); TRELLIS_FF #(.GSR("DISABLED"), .CEMUX("1"), .CLKMUX("CLK"), .LSRMUX("LSR"), .REGSET("SET"), .SRMODE("ASYNC"))  _TECHMAP_REPLACE_ (.CLK(C), .LSR(!R), .DI(D), .Q(Q)); endmodule
-
-module  \$_DFF_NP0_ (input D, C, R, output Q); TRELLIS_FF #(.GSR("DISABLED"), .CEMUX("1"), .CLKMUX("INV"), .LSRMUX("LSR"), .REGSET("RESET"), .SRMODE("ASYNC"))  _TECHMAP_REPLACE_ (.CLK(C), .LSR(R), .DI(D), .Q(Q)); endmodule
-module  \$_DFF_NP1_ (input D, C, R, output Q); TRELLIS_FF #(.GSR("DISABLED"), .CEMUX("1"), .CLKMUX("INV"), .LSRMUX("LSR"), .REGSET("SET"), .SRMODE("ASYNC"))  _TECHMAP_REPLACE_ (.CLK(C), .LSR(R), .DI(D), .Q(Q)); endmodule
-module  \$_DFF_PP0_ (input D, C, R, output Q); TRELLIS_FF #(.GSR("DISABLED"), .CEMUX("1"), .CLKMUX("CLK"), .LSRMUX("LSR"), .REGSET("RESET"), .SRMODE("ASYNC"))  _TECHMAP_REPLACE_ (.CLK(C), .LSR(R), .DI(D), .Q(Q)); endmodule
-module  \$_DFF_PP1_ (input D, C, R, output Q); TRELLIS_FF #(.GSR("DISABLED"), .CEMUX("1"), .CLKMUX("CLK"), .LSRMUX("LSR"), .REGSET("SET"), .SRMODE("ASYNC"))  _TECHMAP_REPLACE_ (.CLK(C), .LSR(R), .DI(D), .Q(Q)); endmodule
-
-module  \$__DFFS_NN0_ (input D, C, R, output Q); TRELLIS_FF #(.GSR("DISABLED"), .CEMUX("1"), .CLKMUX("INV"), .LSRMUX("LSR"), .REGSET("RESET"), .SRMODE("LSR_OVER_CE"))  _TECHMAP_REPLACE_ (.CLK(C), .LSR(!R), .DI(D), .Q(Q)); endmodule
-module  \$__DFFS_NN1_ (input D, C, R, output Q); TRELLIS_FF #(.GSR("DISABLED"), .CEMUX("1"), .CLKMUX("INV"), .LSRMUX("LSR"), .REGSET("SET"), .SRMODE("LSR_OVER_CE"))  _TECHMAP_REPLACE_ (.CLK(C), .LSR(!R), .DI(D), .Q(Q)); endmodule
-module  \$__DFFS_PN0_ (input D, C, R, output Q); TRELLIS_FF #(.GSR("DISABLED"), .CEMUX("1"), .CLKMUX("CLK"), .LSRMUX("LSR"), .REGSET("RESET"), .SRMODE("LSR_OVER_CE"))  _TECHMAP_REPLACE_ (.CLK(C), .LSR(!R), .DI(D), .Q(Q)); endmodule
-module  \$__DFFS_PN1_ (input D, C, R, output Q); TRELLIS_FF #(.GSR("DISABLED"), .CEMUX("1"), .CLKMUX("CLK"), .LSRMUX("LSR"), .REGSET("SET"), .SRMODE("LSR_OVER_CE"))  _TECHMAP_REPLACE_ (.CLK(C), .LSR(!R), .DI(D), .Q(Q)); endmodule
-
-module  \$__DFFS_NP0_ (input D, C, R, output Q); TRELLIS_FF #(.GSR("DISABLED"), .CEMUX("1"), .CLKMUX("INV"), .LSRMUX("LSR"), .REGSET("RESET"), .SRMODE("LSR_OVER_CE"))  _TECHMAP_REPLACE_ (.CLK(C), .LSR(R), .DI(D), .Q(Q)); endmodule
-module  \$__DFFS_NP1_ (input D, C, R, output Q); TRELLIS_FF #(.GSR("DISABLED"), .CEMUX("1"), .CLKMUX("INV"), .LSRMUX("LSR"), .REGSET("SET"), .SRMODE("LSR_OVER_CE"))  _TECHMAP_REPLACE_ (.CLK(C), .LSR(R), .DI(D), .Q(Q)); endmodule
-module  \$__DFFS_PP0_ (input D, C, R, output Q); TRELLIS_FF #(.GSR("DISABLED"), .CEMUX("1"), .CLKMUX("CLK"), .LSRMUX("LSR"), .REGSET("RESET"), .SRMODE("LSR_OVER_CE"))  _TECHMAP_REPLACE_ (.CLK(C), .LSR(R), .DI(D), .Q(Q)); endmodule
-module  \$__DFFS_PP1_ (input D, C, R, output Q); TRELLIS_FF #(.GSR("DISABLED"), .CEMUX("1"), .CLKMUX("CLK"), .LSRMUX("LSR"), .REGSET("SET"), .SRMODE("LSR_OVER_CE"))  _TECHMAP_REPLACE_ (.CLK(C), .LSR(R), .DI(D), .Q(Q)); endmodule
-
-module  \$__DFFE_NN0 (input D, C, E, R, output Q); TRELLIS_FF #(.GSR("DISABLED"), .CEMUX("CE"), .CLKMUX("INV"), .LSRMUX("LSR"), .REGSET("RESET"), .SRMODE("ASYNC"))  _TECHMAP_REPLACE_ (.CLK(C), .CE(E), .LSR(!R), .DI(D), .Q(Q)); endmodule
-module  \$__DFFE_NN1 (input D, C, E, R, output Q); TRELLIS_FF #(.GSR("DISABLED"), .CEMUX("CE"), .CLKMUX("INV"), .LSRMUX("LSR"), .REGSET("SET"), .SRMODE("ASYNC"))  _TECHMAP_REPLACE_ (.CLK(C), .CE(E), .LSR(!R), .DI(D), .Q(Q)); endmodule
-module  \$__DFFE_PN0 (input D, C, E, R, output Q); TRELLIS_FF #(.GSR("DISABLED"), .CEMUX("CE"), .CLKMUX("CLK"), .LSRMUX("LSR"), .REGSET("RESET"), .SRMODE("ASYNC"))  _TECHMAP_REPLACE_ (.CLK(C), .CE(E), .LSR(!R), .DI(D), .Q(Q)); endmodule
-module  \$__DFFE_PN1 (input D, C, E, R, output Q); TRELLIS_FF #(.GSR("DISABLED"), .CEMUX("CE"), .CLKMUX("CLK"), .LSRMUX("LSR"), .REGSET("SET"), .SRMODE("ASYNC"))  _TECHMAP_REPLACE_ (.CLK(C), .CE(E), .LSR(!R), .DI(D), .Q(Q)); endmodule
-
-module  \$__DFFE_NP0 (input D, C, E, R, output Q); TRELLIS_FF #(.GSR("DISABLED"), .CEMUX("CE"), .CLKMUX("INV"), .LSRMUX("LSR"), .REGSET("RESET"), .SRMODE("ASYNC"))  _TECHMAP_REPLACE_ (.CLK(C), .CE(E), .LSR(R), .DI(D), .Q(Q)); endmodule
-module  \$__DFFE_NP1 (input D, C, E, R, output Q); TRELLIS_FF #(.GSR("DISABLED"), .CEMUX("CE"), .CLKMUX("INV"), .LSRMUX("LSR"), .REGSET("SET"), .SRMODE("ASYNC"))  _TECHMAP_REPLACE_ (.CLK(C), .CE(E), .LSR(R), .DI(D), .Q(Q)); endmodule
-module  \$__DFFE_PP0 (input D, C, E, R, output Q); TRELLIS_FF #(.GSR("DISABLED"), .CEMUX("CE"), .CLKMUX("CLK"), .LSRMUX("LSR"), .REGSET("RESET"), .SRMODE("ASYNC"))  _TECHMAP_REPLACE_ (.CLK(C), .CE(E), .LSR(R), .DI(D), .Q(Q)); endmodule
-module  \$__DFFE_PP1 (input D, C, E, R, output Q); TRELLIS_FF #(.GSR("DISABLED"), .CEMUX("CE"), .CLKMUX("CLK"), .LSRMUX("LSR"), .REGSET("SET"), .SRMODE("ASYNC"))  _TECHMAP_REPLACE_ (.CLK(C), .CE(E), .LSR(R), .DI(D), .Q(Q)); endmodule
-
-module  \$__DFFSE_NN0 (input D, C, E, R, output Q); TRELLIS_FF #(.GSR("DISABLED"), .CEMUX("CE"), .CLKMUX("INV"), .LSRMUX("LSR"), .REGSET("RESET"), .SRMODE("LSR_OVER_CE"))  _TECHMAP_REPLACE_ (.CLK(C), .CE(E), .LSR(!R), .DI(D), .Q(Q)); endmodule
-module  \$__DFFSE_NN1 (input D, C, E, R, output Q); TRELLIS_FF #(.GSR("DISABLED"), .CEMUX("CE"), .CLKMUX("INV"), .LSRMUX("LSR"), .REGSET("SET"), .SRMODE("LSR_OVER_CE"))  _TECHMAP_REPLACE_ (.CLK(C), .CE(E), .LSR(!R), .DI(D), .Q(Q)); endmodule
-module  \$__DFFSE_PN0 (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_PN1 (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
-
-module  \$__DFFSE_NP0 (input D, C, E, R, output Q); TRELLIS_FF #(.GSR("DISABLED"), .CEMUX("CE"), .CLKMUX("INV"), .LSRMUX("LSR"), .REGSET("RESET"), .SRMODE("LSR_OVER_CE"))  _TECHMAP_REPLACE_ (.CLK(C), .CE(E), .LSR(R), .DI(D), .Q(Q)); endmodule
-module  \$__DFFSE_NP1 (input D, C, E, R, output Q); TRELLIS_FF #(.GSR("DISABLED"), .CEMUX("CE"), .CLKMUX("INV"), .LSRMUX("LSR"), .REGSET("SET"), .SRMODE("LSR_OVER_CE"))  _TECHMAP_REPLACE_ (.CLK(C), .CE(E), .LSR(R), .DI(D), .Q(Q)); endmodule
-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
+module  \$_DFF_N_ (input D, C, output Q); TRELLIS_FF #(.GSR("AUTO"), .CEMUX("1"), .CLKMUX("INV"), .LSRMUX("LSR"), .REGSET("RESET"))  _TECHMAP_REPLACE_ (.CLK(C), .LSR(1'b0), .DI(D), .Q(Q)); endmodule
+module  \$_DFF_P_ (input D, C, output Q); TRELLIS_FF #(.GSR("AUTO"), .CEMUX("1"), .CLKMUX("CLK"), .LSRMUX("LSR"), .REGSET("RESET"))  _TECHMAP_REPLACE_ (.CLK(C), .LSR(1'b0), .DI(D), .Q(Q)); endmodule
+
+module  \$_DFFE_NN_ (input D, C, E, output Q); TRELLIS_FF #(.GSR("AUTO"), .CEMUX("INV"), .CLKMUX("INV"), .LSRMUX("LSR"), .REGSET("RESET"))  _TECHMAP_REPLACE_ (.CLK(C), .CE(E), .LSR(1'b0), .DI(D), .Q(Q)); endmodule
+module  \$_DFFE_PN_ (input D, C, E, output Q); TRELLIS_FF #(.GSR("AUTO"), .CEMUX("INV"), .CLKMUX("CLK"), .LSRMUX("LSR"), .REGSET("RESET"))  _TECHMAP_REPLACE_ (.CLK(C), .CE(E), .LSR(1'b0), .DI(D), .Q(Q)); endmodule
+
+module  \$_DFFE_NP_ (input D, C, E, output Q); TRELLIS_FF #(.GSR("AUTO"), .CEMUX("CE"), .CLKMUX("INV"), .LSRMUX("LSR"), .REGSET("RESET"))  _TECHMAP_REPLACE_ (.CLK(C), .CE(E), .LSR(1'b0), .DI(D), .Q(Q)); endmodule
+module  \$_DFFE_PP_ (input D, C, E, output Q); TRELLIS_FF #(.GSR("AUTO"), .CEMUX("CE"), .CLKMUX("CLK"), .LSRMUX("LSR"), .REGSET("RESET"))  _TECHMAP_REPLACE_ (.CLK(C), .CE(E), .LSR(1'b0), .DI(D), .Q(Q)); endmodule
+
+module  \$_DFF_NN0_ (input D, C, R, output Q); TRELLIS_FF #(.GSR("AUTO"), .CEMUX("1"), .CLKMUX("INV"), .LSRMUX("LSR"), .REGSET("RESET"), .SRMODE("ASYNC"))  _TECHMAP_REPLACE_ (.CLK(C), .LSR(!R), .DI(D), .Q(Q)); endmodule
+module  \$_DFF_NN1_ (input D, C, R, output Q); TRELLIS_FF #(.GSR("AUTO"), .CEMUX("1"), .CLKMUX("INV"), .LSRMUX("LSR"), .REGSET("SET"), .SRMODE("ASYNC"))  _TECHMAP_REPLACE_ (.CLK(C), .LSR(!R), .DI(D), .Q(Q)); endmodule
+module  \$_DFF_PN0_ (input D, C, R, output Q); TRELLIS_FF #(.GSR("AUTO"), .CEMUX("1"), .CLKMUX("CLK"), .LSRMUX("LSR"), .REGSET("RESET"), .SRMODE("ASYNC"))  _TECHMAP_REPLACE_ (.CLK(C), .LSR(!R), .DI(D), .Q(Q)); endmodule
+module  \$_DFF_PN1_ (input D, C, R, output Q); TRELLIS_FF #(.GSR("AUTO"), .CEMUX("1"), .CLKMUX("CLK"), .LSRMUX("LSR"), .REGSET("SET"), .SRMODE("ASYNC"))  _TECHMAP_REPLACE_ (.CLK(C), .LSR(!R), .DI(D), .Q(Q)); endmodule
+
+module  \$_DFF_NP0_ (input D, C, R, output Q); TRELLIS_FF #(.GSR("AUTO"), .CEMUX("1"), .CLKMUX("INV"), .LSRMUX("LSR"), .REGSET("RESET"), .SRMODE("ASYNC"))  _TECHMAP_REPLACE_ (.CLK(C), .LSR(R), .DI(D), .Q(Q)); endmodule
+module  \$_DFF_NP1_ (input D, C, R, output Q); TRELLIS_FF #(.GSR("AUTO"), .CEMUX("1"), .CLKMUX("INV"), .LSRMUX("LSR"), .REGSET("SET"), .SRMODE("ASYNC"))  _TECHMAP_REPLACE_ (.CLK(C), .LSR(R), .DI(D), .Q(Q)); endmodule
+module  \$_DFF_PP0_ (input D, C, R, output Q); TRELLIS_FF #(.GSR("AUTO"), .CEMUX("1"), .CLKMUX("CLK"), .LSRMUX("LSR"), .REGSET("RESET"), .SRMODE("ASYNC"))  _TECHMAP_REPLACE_ (.CLK(C), .LSR(R), .DI(D), .Q(Q)); endmodule
+module  \$_DFF_PP1_ (input D, C, R, output Q); TRELLIS_FF #(.GSR("AUTO"), .CEMUX("1"), .CLKMUX("CLK"), .LSRMUX("LSR"), .REGSET("SET"), .SRMODE("ASYNC"))  _TECHMAP_REPLACE_ (.CLK(C), .LSR(R), .DI(D), .Q(Q)); endmodule
+
+module  \$__DFFS_NN0_ (input D, C, R, output Q); TRELLIS_FF #(.GSR("AUTO"), .CEMUX("1"), .CLKMUX("INV"), .LSRMUX("LSR"), .REGSET("RESET"), .SRMODE("LSR_OVER_CE"))  _TECHMAP_REPLACE_ (.CLK(C), .LSR(!R), .DI(D), .Q(Q)); endmodule
+module  \$__DFFS_NN1_ (input D, C, R, output Q); TRELLIS_FF #(.GSR("AUTO"), .CEMUX("1"), .CLKMUX("INV"), .LSRMUX("LSR"), .REGSET("SET"), .SRMODE("LSR_OVER_CE"))  _TECHMAP_REPLACE_ (.CLK(C), .LSR(!R), .DI(D), .Q(Q)); endmodule
+module  \$__DFFS_PN0_ (input D, C, R, output Q); TRELLIS_FF #(.GSR("AUTO"), .CEMUX("1"), .CLKMUX("CLK"), .LSRMUX("LSR"), .REGSET("RESET"), .SRMODE("LSR_OVER_CE"))  _TECHMAP_REPLACE_ (.CLK(C), .LSR(!R), .DI(D), .Q(Q)); endmodule
+module  \$__DFFS_PN1_ (input D, C, R, output Q); TRELLIS_FF #(.GSR("AUTO"), .CEMUX("1"), .CLKMUX("CLK"), .LSRMUX("LSR"), .REGSET("SET"), .SRMODE("LSR_OVER_CE"))  _TECHMAP_REPLACE_ (.CLK(C), .LSR(!R), .DI(D), .Q(Q)); endmodule
+
+module  \$__DFFS_NP0_ (input D, C, R, output Q); TRELLIS_FF #(.GSR("AUTO"), .CEMUX("1"), .CLKMUX("INV"), .LSRMUX("LSR"), .REGSET("RESET"), .SRMODE("LSR_OVER_CE"))  _TECHMAP_REPLACE_ (.CLK(C), .LSR(R), .DI(D), .Q(Q)); endmodule
+module  \$__DFFS_NP1_ (input D, C, R, output Q); TRELLIS_FF #(.GSR("AUTO"), .CEMUX("1"), .CLKMUX("INV"), .LSRMUX("LSR"), .REGSET("SET"), .SRMODE("LSR_OVER_CE"))  _TECHMAP_REPLACE_ (.CLK(C), .LSR(R), .DI(D), .Q(Q)); endmodule
+module  \$__DFFS_PP0_ (input D, C, R, output Q); TRELLIS_FF #(.GSR("AUTO"), .CEMUX("1"), .CLKMUX("CLK"), .LSRMUX("LSR"), .REGSET("RESET"), .SRMODE("LSR_OVER_CE"))  _TECHMAP_REPLACE_ (.CLK(C), .LSR(R), .DI(D), .Q(Q)); endmodule
+module  \$__DFFS_PP1_ (input D, C, R, output Q); TRELLIS_FF #(.GSR("AUTO"), .CEMUX("1"), .CLKMUX("CLK"), .LSRMUX("LSR"), .REGSET("SET"), .SRMODE("LSR_OVER_CE"))  _TECHMAP_REPLACE_ (.CLK(C), .LSR(R), .DI(D), .Q(Q)); endmodule
+
+module  \$__DFFE_NN0 (input D, C, E, R, output Q); TRELLIS_FF #(.GSR("AUTO"), .CEMUX("CE"), .CLKMUX("INV"), .LSRMUX("LSR"), .REGSET("RESET"), .SRMODE("ASYNC"))  _TECHMAP_REPLACE_ (.CLK(C), .CE(E), .LSR(!R), .DI(D), .Q(Q)); endmodule
+module  \$__DFFE_NN1 (input D, C, E, R, output Q); TRELLIS_FF #(.GSR("AUTO"), .CEMUX("CE"), .CLKMUX("INV"), .LSRMUX("LSR"), .REGSET("SET"), .SRMODE("ASYNC"))  _TECHMAP_REPLACE_ (.CLK(C), .CE(E), .LSR(!R), .DI(D), .Q(Q)); endmodule
+module  \$__DFFE_PN0 (input D, C, E, R, output Q); TRELLIS_FF #(.GSR("AUTO"), .CEMUX("CE"), .CLKMUX("CLK"), .LSRMUX("LSR"), .REGSET("RESET"), .SRMODE("ASYNC"))  _TECHMAP_REPLACE_ (.CLK(C), .CE(E), .LSR(!R), .DI(D), .Q(Q)); endmodule
+module  \$__DFFE_PN1 (input D, C, E, R, output Q); TRELLIS_FF #(.GSR("AUTO"), .CEMUX("CE"), .CLKMUX("CLK"), .LSRMUX("LSR"), .REGSET("SET"), .SRMODE("ASYNC"))  _TECHMAP_REPLACE_ (.CLK(C), .CE(E), .LSR(!R), .DI(D), .Q(Q)); endmodule
+
+module  \$__DFFE_NP0 (input D, C, E, R, output Q); TRELLIS_FF #(.GSR("AUTO"), .CEMUX("CE"), .CLKMUX("INV"), .LSRMUX("LSR"), .REGSET("RESET"), .SRMODE("ASYNC"))  _TECHMAP_REPLACE_ (.CLK(C), .CE(E), .LSR(R), .DI(D), .Q(Q)); endmodule
+module  \$__DFFE_NP1 (input D, C, E, R, output Q); TRELLIS_FF #(.GSR("AUTO"), .CEMUX("CE"), .CLKMUX("INV"), .LSRMUX("LSR"), .REGSET("SET"), .SRMODE("ASYNC"))  _TECHMAP_REPLACE_ (.CLK(C), .CE(E), .LSR(R), .DI(D), .Q(Q)); endmodule
+module  \$__DFFE_PP0 (input D, C, E, R, output Q); TRELLIS_FF #(.GSR("AUTO"), .CEMUX("CE"), .CLKMUX("CLK"), .LSRMUX("LSR"), .REGSET("RESET"), .SRMODE("ASYNC"))  _TECHMAP_REPLACE_ (.CLK(C), .CE(E), .LSR(R), .DI(D), .Q(Q)); endmodule
+module  \$__DFFE_PP1 (input D, C, E, R, output Q); TRELLIS_FF #(.GSR("AUTO"), .CEMUX("CE"), .CLKMUX("CLK"), .LSRMUX("LSR"), .REGSET("SET"), .SRMODE("ASYNC"))  _TECHMAP_REPLACE_ (.CLK(C), .CE(E), .LSR(R), .DI(D), .Q(Q)); endmodule
+
+module  \$__DFFSE_NN0 (input D, C, E, R, output Q); TRELLIS_FF #(.GSR("AUTO"), .CEMUX("CE"), .CLKMUX("INV"), .LSRMUX("LSR"), .REGSET("RESET"), .SRMODE("LSR_OVER_CE"))  _TECHMAP_REPLACE_ (.CLK(C), .CE(E), .LSR(!R), .DI(D), .Q(Q)); endmodule
+module  \$__DFFSE_NN1 (input D, C, E, R, output Q); TRELLIS_FF #(.GSR("AUTO"), .CEMUX("CE"), .CLKMUX("INV"), .LSRMUX("LSR"), .REGSET("SET"), .SRMODE("LSR_OVER_CE"))  _TECHMAP_REPLACE_ (.CLK(C), .CE(E), .LSR(!R), .DI(D), .Q(Q)); endmodule
+module  \$__DFFSE_PN0 (input D, C, E, R, output Q); TRELLIS_FF #(.GSR("AUTO"), .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_PN1 (input D, C, E, R, output Q); TRELLIS_FF #(.GSR("AUTO"), .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
+
+module  \$__DFFSE_NP0 (input D, C, E, R, output Q); TRELLIS_FF #(.GSR("AUTO"), .CEMUX("CE"), .CLKMUX("INV"), .LSRMUX("LSR"), .REGSET("RESET"), .SRMODE("LSR_OVER_CE"))  _TECHMAP_REPLACE_ (.CLK(C), .CE(E), .LSR(R), .DI(D), .Q(Q)); endmodule
+module  \$__DFFSE_NP1 (input D, C, E, R, output Q); TRELLIS_FF #(.GSR("AUTO"), .CEMUX("CE"), .CLKMUX("INV"), .LSRMUX("LSR"), .REGSET("SET"), .SRMODE("LSR_OVER_CE"))  _TECHMAP_REPLACE_ (.CLK(C), .CE(E), .LSR(R), .DI(D), .Q(Q)); endmodule
+module  \$__DFFSE_PP0 (input D, C, E, R, output Q); TRELLIS_FF #(.GSR("AUTO"), .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("AUTO"), .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
 
 // TODO: Diamond flip-flops
 // module FD1P3AX(); endmodule
diff --git a/techlibs/ecp5/ecp5_gsr.cc b/techlibs/ecp5/ecp5_gsr.cc
new file mode 100644
index 000000000..8b8927d31
--- /dev/null
+++ b/techlibs/ecp5/ecp5_gsr.cc
@@ -0,0 +1,135 @@
+/*
+ *  yosys -- Yosys Open SYnthesis Suite
+ *
+ *  Copyright (C) 2012  Clifford Wolf <clifford@clifford.at>
+ *  Copyright (C) 2019  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 Ecp5GsrPass : public Pass {
+	Ecp5GsrPass() : Pass("ecp5_gsr", "ECP5: handle GSR") { }
+	void help() YS_OVERRIDE
+	{
+		//   |---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|
+		log("\n");
+		log("    ecp5_gsr [options] [selection]\n");
+		log("\n");
+		log("Trim active low async resets connected to GSR and resolve GSR parameter,\n");
+		log("if a GSR or SGSR primitive is used in the design.\n");
+		log("\n");
+		log("If any cell has the GSR parameter set to \"AUTO\", this will be resolved\n");
+		log("to \"ENABLED\" if a GSR primitive is present and the (* nogsr *) attribute\n");
+		log("is not set, otherwise it will be resolved to \"DISABLED\".\n");
+		log("\n");
+	}
+	void execute(std::vector<std::string> args, RTLIL::Design *design) YS_OVERRIDE
+	{
+		log_header(design, "Executing ECP5_GSR 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 GSR in %s.\n", log_id(module));
+
+			SigMap sigmap(module);
+
+			SigBit gsr;
+			bool found_gsr = false;
+
+			for (auto cell : module->selected_cells())
+			{
+				if (cell->type != ID(GSR) && cell->type != ID(SGSR))
+					continue;
+				if (found_gsr)
+					log_error("Found more than one GSR or SGSR cell in module %s.\n", log_id(module));
+				found_gsr = true;
+				SigSpec sig_gsr = cell->getPort(ID(GSR));
+				if (GetSize(sig_gsr) < 1)
+					log_error("GSR cell %s has disconnected GSR input.\n", log_id(cell));
+				gsr = sigmap(sig_gsr[0]);
+			}
+
+			// Resolve GSR parameter
+
+			for (auto cell : module->selected_cells())
+			{
+				if (!cell->hasParam(ID(GSR)) || cell->getParam(ID(GSR)).decode_string() != "AUTO")
+					continue;
+				
+				bool gsren = found_gsr;
+				if (cell->get_bool_attribute("\\nogsr"))
+					gsren = false;
+				cell->setParam(ID(GSR), gsren ? Const("ENABLED") : Const("DISABLED"));
+				
+			}
+
+			if (!found_gsr)
+				continue;
+
+			// For finding active low FF inputs
+			pool<SigBit> inverted_gsr;
+
+			log_debug("GSR net in module %s is %s.\n", log_id(module), log_signal(gsr));
+			for (auto cell : module->selected_cells())
+			{
+				if (cell->type != ID($_NOT_))
+					continue;
+				SigSpec sig_a = cell->getPort(ID(A)), sig_y = cell->getPort(ID(Y));
+				if (GetSize(sig_a) < 1 || GetSize(sig_y) < 1)
+					continue;
+				SigBit a = sigmap(sig_a[0]);
+				if (a == gsr)
+					inverted_gsr.insert(sigmap(sig_y[0]));
+			}
+
+			for (auto cell : module->selected_cells())
+			{
+				if (cell->type != ID(TRELLIS_FF))
+					continue;
+				if (!cell->hasParam(ID(GSR)) || cell->getParam(ID(GSR)).decode_string() != "ENABLED")
+					continue;
+				if (!cell->hasParam(ID(SRMODE)) || cell->getParam(ID(SRMODE)).decode_string() != "ASYNC")
+					continue;
+				SigSpec sig_lsr = cell->getPort(ID(LSR));
+				if (GetSize(sig_lsr) < 1)
+					continue;
+				SigBit lsr = sigmap(sig_lsr[0]);
+				if (!inverted_gsr.count(lsr))
+					continue;
+				cell->setParam(ID(SRMODE), Const("SYNC"));
+				cell->unsetPort(ID(LSR));
+			}
+
+		}
+	}
+} Ecp5GsrPass;
+
+PRIVATE_NAMESPACE_END
diff --git a/techlibs/ecp5/synth_ecp5.cc b/techlibs/ecp5/synth_ecp5.cc
index 143d1f95c..a8075e86e 100644
--- a/techlibs/ecp5/synth_ecp5.cc
+++ b/techlibs/ecp5/synth_ecp5.cc
@@ -271,6 +271,8 @@ struct SynthEcp5Pass : public ScriptPass
 			run("opt_expr -undriven -mux_undef");
 			run("simplemap");
 			run("ecp5_ffinit");
+			run("ecp5_gsr");
+			run("opt_clean");
 		}
 
 		if (check_label("map_luts"))