From e7a3f6377c18b346f455f5f7e5ad2a73d0a032f7 Mon Sep 17 00:00:00 2001
From: David Phillips <david@yeah.nah.nz>
Date: Mon, 25 Oct 2021 14:54:57 +1300
Subject: Initial commit

---
 .gitignore |  4 ++++
 Makefile   | 38 ++++++++++++++++++++++++++++++++++++++
 blink.v    | 23 +++++++++++++++++++++++
 top.lpf    | 24 ++++++++++++++++++++++++
 top.v      | 17 +++++++++++++++++
 5 files changed, 106 insertions(+)
 create mode 100644 .gitignore
 create mode 100644 Makefile
 create mode 100644 blink.v
 create mode 100644 top.lpf
 create mode 100644 top.v

diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..de9b7e5
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,4 @@
+*.svf
+*.bit
+*.json
+*.config
diff --git a/Makefile b/Makefile
new file mode 100644
index 0000000..a1842aa
--- /dev/null
+++ b/Makefile
@@ -0,0 +1,38 @@
+TOP = top
+OBJS = top.v blink.v
+
+FREQ_MHZ = 65
+DEVICE_TYPE = 25k
+PACKAGE = CABGA256
+SPEED_GRADE = 6
+
+.PHONY: all clean program
+all: $(TOP).svf
+
+clean:
+	rm -f *.svf *.bit *.json
+
+program: $(TOP).svf
+	# probably not very useful to anyone without more configurable paths
+	openocd -f /usr/share/openocd/scripts/interface/ftdi/dp_busblaster_kt-link.cfg \
+	        -f ~/jtag/5a-75e.cfg \
+	        -c "init; svf $^; shutdown"
+
+%.json: $(OBJS)
+	yosys -p "synth_ecp5 -json $@" $(OBJS)
+
+%.config: %.json %.lpf
+	nextpnr-ecp5 \
+		--$(DEVICE_TYPE) \
+		--package $(PACKAGE) \
+		--speed $(SPEED_GRADE) \
+		--freq $(FREQ_MHZ) \
+		--json $< \
+		--textcfg $@ \
+		--lpf $(word 2,$^)
+
+%.bit %.svf: %.config
+	ecppack \
+		--bit "$*.bit" \
+		--svf "$*.svf" \
+		--input "$^"
diff --git a/blink.v b/blink.v
new file mode 100644
index 0000000..d11cd1c
--- /dev/null
+++ b/blink.v
@@ -0,0 +1,23 @@
+module blink(
+	input rst_i,
+	input clk_i,
+	output reg led_o
+);
+
+parameter COUNTER_WIDTH = 32;
+parameter OVERFLOW = 25_000_000;
+
+reg[COUNTER_WIDTH-1:0] counter;
+
+always @(posedge clk_i) begin
+	if (rst_i) begin
+		counter <= 0;
+		led <= 1;
+	end else if (counter == OVERFLOW-1) begin
+		led_o <= ~led_o;
+		counter <= 0;
+	end else
+		counter <= counter + 1;
+end
+
+endmodule
diff --git a/top.lpf b/top.lpf
new file mode 100644
index 0000000..16ad6e7
--- /dev/null
+++ b/top.lpf
@@ -0,0 +1,24 @@
+LOCATE    COMP "clk_i"        SITE "P6";
+IOBUF     PORT "clk_i"        IO_TYPE=LVCMOS33;
+FREQUENCY PORT "clk_i"        25 MHZ;
+
+LOCATE    COMP "led_o"        SITE "P11";
+IOBUF     PORT "led_o"        IO_TYPE=LVCMOS33;
+
+LOCATE    COMP "oe_n_o"       SITE "F12";
+IOBUF     PORT "oe_n_o"       IO_TYPE=LVCMOS33;
+
+#LOCATE    COMP "clk25M_o"     SITE "J14";
+#IOBUF     PORT "clk25M_o"     IO_TYPE=LVCMOS33;
+#LOCATE    COMP "clk12M5_o"    SITE "K2";
+#IOBUF     PORT "clk12M5_o"    IO_TYPE=LVCMOS33;
+#LOCATE    COMP "clk6M25_o"    SITE "K1";
+#IOBUF     PORT "clk6M25_o"    IO_TYPE=LVCMOS33;
+#LOCATE    COMP "clk5M_o"      SITE "F15";
+#IOBUF     PORT "clk5M_o"      IO_TYPE=LVCMOS33;
+#LOCATE    COMP "clk4M17_o"    SITE "F13";
+#IOBUF     PORT "clk4M17_o"    IO_TYPE=LVCMOS33;
+#LOCATE    COMP "clk3M57_o"    SITE "G12";
+#IOBUF     PORT "clk3M57_o"    IO_TYPE=LVCMOS33;
+#LOCATE    COMP "clk3M125_o"   SITE "G13";
+#IOBUF     PORT "clk3M125_o"   IO_TYPE=LVCMOS33;
diff --git a/top.v b/top.v
new file mode 100644
index 0000000..6d98150
--- /dev/null
+++ b/top.v
@@ -0,0 +1,17 @@
+module top(
+	input clk_i,
+	output led_o,
+);
+
+blink #(
+	.COUNTER_WIDTH(24),
+	// 25 MHz clock => 1 Hz
+	.OVERFLOW(12_500_000)
+)
+blink_inst(
+	.clk_i(clk_i),
+	.rst_i(1'b0),
+	.led_o(led_o)
+);
+
+endmodule
-- 
cgit v1.1