* Reorganization / modularization of the Makefile (we start to have

a number of boards, time to create one file per board, easier to
  maintain !)

Basic/FomuBlink/blink.v

@@ -0,0 +1,83 @@
+// Simple tri-colour LED blink example.
+
+// Correctly map pins for the iCE40UP5K SB_RGBA_DRV hard macro.
+// The variables EVT, PVT and HACKER are set from the Makefile.
+`ifdef EVT
+`define BLUEPWM  RGB0PWM
+`define REDPWM   RGB1PWM
+`define GREENPWM RGB2PWM
+`elsif HACKER
+`define BLUEPWM  RGB0PWM
+`define GREENPWM RGB1PWM
+`define REDPWM   RGB2PWM
+`elsif PVT
+`define GREENPWM RGB0PWM
+`define REDPWM   RGB1PWM
+`define BLUEPWM  RGB2PWM
+`else
+`error_board_not_supported
+`endif
+
+module top (
+    // 48MHz Clock input
+    // --------
+    input clki,
+    // LED outputs
+    // --------
+    output rgb0,
+    output rgb1,
+    output rgb2,
+    // USB Pins (which should be statically driven if not being used).
+    // --------
+    output usb_dp,
+    output usb_dn,
+    output usb_dp_pu
+);
+
+    // Assign USB pins to "0" so as to disconnect Fomu from
+    // the host system.  Otherwise it would try to talk to
+    // us over USB, which wouldn't work since we have no stack.
+    assign usb_dp = 1'b0;
+    assign usb_dn = 1'b0;
+    assign usb_dp_pu = 1'b0;
+
+    // Connect to system clock (with buffering)
+    wire clk;
+    SB_GB clk_gb (
+        .USER_SIGNAL_TO_GLOBAL_BUFFER(clki),
+        .GLOBAL_BUFFER_OUTPUT(clk)
+    );
+
+    // Use counter logic to divide system clock.  The clock is 48 MHz,
+    // so we divide it down by 2^28.
+    reg [28:0] counter = 0;
+    always @(posedge clk) begin
+        counter <= counter + 1;
+    end
+
+    // Instantiate iCE40 LED driver hard logic, connecting up
+    // counter state and LEDs.
+    //
+    // Note that it's possible to drive the LEDs directly,
+    // however that is not current-limited and results in
+    // overvolting the red LED.
+    //
+    // See also:
+    // https://www.latticesemi.com/-/media/LatticeSemi/Documents/ApplicationNotes/IK/ICE40LEDDriverUsageGuide.ashx?document_id=50668
+    SB_RGBA_DRV #(
+        .CURRENT_MODE("0b1"),       // half current
+        .RGB0_CURRENT("0b000011"),  // 4 mA
+        .RGB1_CURRENT("0b000011"),  // 4 mA
+        .RGB2_CURRENT("0b000011")   // 4 mA
+    ) RGBA_DRIVER (
+        .CURREN(1'b1),
+        .RGBLEDEN(1'b1),
+        .`BLUEPWM(counter[25]),     // Blue
+        .`REDPWM(counter[24]),      // Red
+        .`GREENPWM(counter[23]),    // Green
+        .RGB0(rgb0),
+        .RGB1(rgb1),
+        .RGB2(rgb2)
+    );
+
+endmodule

Basic/FomuBlink/fomu-pvt.pcf

@@ -0,0 +1,29 @@
+set_io rgb0 A5
+set_io rgb1 B5
+set_io rgb2 C5
+set_io pmod_1 E4
+set_io pmod_2 D5
+set_io pmod_3 E5
+set_io pmod_4 F5
+set_io pmoda_1 E4
+set_io pmoda_2 D5
+set_io pmoda_3 E5
+set_io pmoda_4 F5
+set_io clki F4
+set_io user_1 E4
+set_io user_2 D5
+set_io user_3 E5
+set_io user_4 F5
+set_io touch_1 E4
+set_io touch_2 D5
+set_io touch_3 E5
+set_io touch_4 F5
+set_io spi_mosi F1
+set_io spi_miso E1
+set_io spi_clk D1
+set_io spi_io2 F2
+set_io spi_io3 B1
+set_io spi_cs C1
+set_io usb_dn A2
+set_io usb_dp A1
+set_io usb_dp_pu A4

Basic/FomuBlink/makeit.sh

@@ -0,0 +1,9 @@
+yosys -DPVT -p 'synth_ice40 -top top -json blink.json' blink.v
+nextpnr-ice40 --up5k --package uwg30 --pcf fomu-pvt.pcf --json blink.json --asc blink.asc
+icepack blink.asc blink.bit
+cp blink.bit blink.dfu
+dfu-suffix -v 1209 -p 70b1 -a blink.dfu
+dfu-util -D blink.dfu
+
+
+