dedicated output for LUT in GENERIC_SLICE

6 files changed, 31 insertions, 32 deletions

diff --git a/generic/cells.cc b/generic/cells.cc
index 53886e33..3b754406 100644
--- a/generic/cells.cc
+++ b/generic/cells.cc
@@ -44,13 +44,13 @@ std::unique_ptr<CellInfo> create_generic_cell(Context *ctx, IdString type, std::
     if (type == ctx->id("GENERIC_SLICE")) {
         new_cell->params[ctx->id("K")] = std::to_string(ctx->args.K);
         new_cell->params[ctx->id("INIT")] = 0;
-        new_cell->params[ctx->id("FF_USED")] = 0;
 
         for (int i = 0; i < ctx->args.K; i++)
             add_port(ctx, new_cell.get(), "I[" + std::to_string(i) + "]", PORT_IN);
 
         add_port(ctx, new_cell.get(), "CLK", PORT_IN);
 
+        add_port(ctx, new_cell.get(), "F", PORT_OUT);
         add_port(ctx, new_cell.get(), "Q", PORT_OUT);
     } else if (type == ctx->id("GENERIC_IOB")) {
         new_cell->params[ctx->id("INPUT_USED")] = 0;
@@ -80,18 +80,16 @@ void lut_to_lc(const Context *ctx, CellInfo *lut, CellInfo *lc, bool no_dff)
     }
 
     if (no_dff) {
-        replace_port(lut, ctx->id("Q"), lc, ctx->id("Q"));
-        lc->params[ctx->id("FF_USED")] = 0;
+        replace_port(lut, ctx->id("Q"), lc, ctx->id("F"));
     }
 }
 
 void dff_to_lc(const Context *ctx, CellInfo *dff, CellInfo *lc, bool pass_thru_lut)
 {
-    lc->params[ctx->id("FF_USED")] = 1;
     replace_port(dff, ctx->id("CLK"), lc, ctx->id("CLK"));
 
     if (pass_thru_lut) {
-        lc->params[ctx->id("INIT")] = 2;
+        lc->params[ctx->id("INIT")] = 0xAAAA;
         replace_port(dff, ctx->id("D"), lc, ctx->id("I[0]"));
     }
 
diff --git a/generic/examples/bitstream.py b/generic/examples/bitstream.py
index 1ab94f0c..6cd63a58 100644
--- a/generic/examples/bitstream.py
+++ b/generic/examples/bitstream.py
@@ -6,7 +6,6 @@ from simple_config import K
 param_map = {
 	("GENERIC_SLICE", "K"): ParameterConfig(write=False),
 	("GENERIC_SLICE", "INIT"): ParameterConfig(write=True, numeric=True, width=2**K),
-	("GENERIC_SLICE", "FF_USED"): ParameterConfig(write=True, numeric=True, width=1),
 
 	("GENERIC_IOB", "INPUT_USED"): ParameterConfig(write=True, numeric=True, width=1),
 	("GENERIC_IOB", "OUTPUT_USED"): ParameterConfig(write=True, numeric=True, width=1),
@@ -14,4 +13,4 @@ param_map = {
 }
 
 with open("blinky.fasm", "w") as f:
-	write_fasm(ctx, param_map, f)
\ No newline at end of file
+	write_fasm(ctx, param_map, f)
diff --git a/generic/examples/simple.py b/generic/examples/simple.py
index 9339b68a..9379b505 100644
--- a/generic/examples/simple.py
+++ b/generic/examples/simple.py
@@ -9,6 +9,7 @@ for x in range(X):
 		for z in range(N):
 			ctx.addWire(name="X%dY%dZ%d_CLK" % (x, y, z), type="BEL_CLK", x=x, y=y)
 			ctx.addWire(name="X%dY%dZ%d_Q" % (x, y, z), type="BEL_Q", x=x, y=y)
+			ctx.addWire(name="X%dY%dZ%d_F" % (x, y, z), type="BEL_F", x=x, y=y)
 			for i in range(K):
 				ctx.addWire(name="X%dY%dZ%d_I%d" % (x, y, z, i), type="BEL_I", x=x, y=y)
 		# Local wires
@@ -29,6 +30,7 @@ for x in range(X):
 				ctx.addBelInput(bel="X%dY%d_SLICE%d" % (x, y, z), name="CLK", wire="X%dY%dZ%d_CLK" % (x, y, z))
 				for k in range(K):
 					ctx.addBelInput(bel="X%dY%d_SLICE%d" % (x, y, z), name="I[%d]" % k, wire="X%dY%dZ%d_I%d" % (x, y, z, k))
+				ctx.addBelOutput(bel="X%dY%d_SLICE%d" % (x, y, z), name="F", wire="X%dY%dZ%d_F" % (x, y, z))
 				ctx.addBelOutput(bel="X%dY%d_SLICE%d" % (x, y, z), name="Q", wire="X%dY%dZ%d_Q" % (x, y, z))
 
 for x in range(X):
@@ -48,6 +50,9 @@ for x in range(X):
 		# Pips from bel outputs to locals
 		def create_output_pips(dst, offset, skip):
 			for i in range(offset % skip, N, skip):
+				src = "X%dY%dZ%d_F" % (x, y, i)
+				ctx.addPip(name="X%dY%d.%s.%s" % (x, y, src, dst), type="BEL_OUTPUT",
+					srcWire=src, dstWire=dst, delay=ctx.getDelayFromNS(0.05), loc=Loc(x, y, 0))
 				src = "X%dY%dZ%d_Q" % (x, y, i)
 				ctx.addPip(name="X%dY%d.%s.%s" % (x, y, src, dst), type="BEL_OUTPUT",
 					srcWire=src, dstWire=dst, delay=ctx.getDelayFromNS(0.05), loc=Loc(x, y, 0))
@@ -69,4 +74,4 @@ for x in range(X):
 			create_neighbour_pips(dst, x, y+1, (l + 4) % Sl, Sl)
 			create_neighbour_pips(dst, x+1, y-1, (l + 5) % Sl, Sl)
 			create_neighbour_pips(dst, x+1, y, (l + 6) % Sl, Sl)
-			create_neighbour_pips(dst, x+1, y+1, (l + 7) % Sl, Sl)
\ No newline at end of file
+			create_neighbour_pips(dst, x+1, y+1, (l + 7) % Sl, Sl)
diff --git a/generic/examples/simple.sh b/generic/examples/simple.sh
index 8ae903f9..76bc6168 100755
--- a/generic/examples/simple.sh
+++ b/generic/examples/simple.sh
@@ -1,4 +1,5 @@
 #!/usr/bin/env bash
 set -ex
 yosys -p "tcl ../synth/synth_generic.tcl 4 blinky.json" blinky.v
-${NEXTPNR:-../../nextpnr-generic} --pre-pack simple.py --pre-place simple_timing.py --json blinky.json --post-route bitstream.py
+${NEXTPNR:-../../nextpnr-generic} --pre-pack simple.py --pre-place simple_timing.py --json blinky.json --post-route bitstream.py --write pnrblinky.json
+yosys -p "read_verilog -lib ../synth/prims.v; read_json pnrblinky.json; dump -o blinky.il; show -format png -prefix blinky"
diff --git a/generic/examples/simple_timing.py b/generic/examples/simple_timing.py
index 2ccb197e..1067b556 100644
--- a/generic/examples/simple_timing.py
+++ b/generic/examples/simple_timing.py
@@ -1,15 +1,13 @@
 for cname, cell in ctx.cells:
-	if cell.type != "GENERIC_SLICE":
-		continue
-	if cname in ("$PACKER_GND", "$PACKER_VCC"):
-		continue
-	K = int(cell.params["K"])
-	if int(cell.params["FF_USED"], 2) == 1:
-		ctx.addCellTimingClock(cell=cname, port="CLK")
-		for i in range(K):
-			ctx.addCellTimingSetupHold(cell=cname, port="I[%d]" % i, clock="CLK",
-				setup=ctx.getDelayFromNS(0.2), hold=ctx.getDelayFromNS(0))
-		ctx.addCellTimingClockToOut(cell=cname, port="Q", clock="CLK", clktoq=ctx.getDelayFromNS(0.2))
-	else:
-		for i in range(K):
-			ctx.addCellTimingDelay(cell=cname, fromPort="I[%d]" % i, toPort="Q", delay=ctx.getDelayFromNS(0.2))
\ No newline at end of file
+    if cell.type != "GENERIC_SLICE":
+        continue
+    if cname in ("$PACKER_GND", "$PACKER_VCC"):
+        continue
+    K = int(cell.params["K"])
+    ctx.addCellTimingClock(cell=cname, port="CLK")
+    for i in range(K):
+        ctx.addCellTimingSetupHold(cell=cname, port="I[%d]" % i, clock="CLK",
+            setup=ctx.getDelayFromNS(0.2), hold=ctx.getDelayFromNS(0))
+    ctx.addCellTimingClockToOut(cell=cname, port="Q", clock="CLK", clktoq=ctx.getDelayFromNS(0.2))
+    for i in range(K):
+        ctx.addCellTimingDelay(cell=cname, fromPort="I[%d]" % i, toPort="F", delay=ctx.getDelayFromNS(0.2))
diff --git a/generic/synth/prims.v b/generic/synth/prims.v
index 95fcfac7..47a5df0f 100644
--- a/generic/synth/prims.v
+++ b/generic/synth/prims.v
@@ -21,21 +21,19 @@ endmodule
 module GENERIC_SLICE #(
 	parameter K = 4,
 	parameter [2**K-1:0] INIT = 0,
-	parameter FF_USED = 1'b0
 ) (
 	input CLK,
 	input [K-1:0] I,
+  output F,
 	output Q
 );
+  wire f_wire;
 	
-	wire lut_q;
-	LUT #(.K(K), .INIT(INIT)) lut_i(.I(I), .Q(lut_q));
+	LUT #(.K(K), .INIT(INIT)) lut_i(.I(I), .Q(f_wire));
 
-	generate if (FF_USED)
-		DFF dff_i(.CLK(CLK), .D(lut_q), .Q(Q));
-	else
-		assign Q = lut_q; 
-	endgenerate
+  DFF dff_i(.CLK(CLK), .D(f_wire), .Q(Q));
+
+  assign F = f_wire;
 endmodule
 
 module GENERIC_IOB #(
@@ -56,4 +54,4 @@ module GENERIC_IOB #(
 	generate if (INPUT_USED)
 		assign O = PAD;
 	endgenerate
-endmodule
\ No newline at end of file
+endmodule