Added FOMU VGA example

Basic/FOMU_VGA/fomu-pvt.pcf

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+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/FOMU_VGA/makeit.sh

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+yosys -DPVT -p 'synth_ice40 -dsp -top vga -json vga.json' vga.v
+nextpnr-ice40 --up5k --package uwg30 --pcf fomu-pvt.pcf --json vga.json --asc vga.asc
+icepack vga.asc vga.bit
+cp vga.bit vga.dfu
+dfu-suffix -v 1209 -p 70b1 -a vga.dfu
+dfu-util -D vga.dfu
+
+
+

Basic/FOMU_VGA/vga.v

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+
+  module vga (
+                input clki,      // ->48 Mhz clock input
+                output rgb0,     // \
+                output rgb1,     //  >LED
+                output rgb2,     // /
+                output user_1,   // ->hsync
+                output user_2,   // ->vsync
+                output user_3,   // ->color0
+                output user_4,   // ->color1
+                output usb_dp,   // \
+                output usb_dn,   //  >USB pins (should be driven low if not used)
+                output usb_dp_pu // /
+  );
+
+  assign usb_dp=0;
+  assign usb_dn=0;
+  assign usb_dp_pu=0;
+  
+  wire hs;
+  wire vs;
+  reg pixel;
+
+  wire [31:0] dist = (counter_x - 320)*(counter_x - 320) + (counter_y - 200) * (counter_y - 200) - (counter << 8);
+
+  reg [31:0] counter;
+
+  assign user_1 = hs;
+  assign user_2 = vs;
+  assign user_3 = dist[15]; // pixel;
+  assign user_4 = dist[14]; // 0;
+
+  SB_PLL40_CORE #(
+                  .FEEDBACK_PATH("SIMPLE"),
+                  .DIVR(4'b0010),
+                  .DIVF(7'b0100111),
+                  .DIVQ(3'b100),
+                  .FILTER_RANGE(3'b001),
+                  ) uut (
+                         .REFERENCECLK   (clki),
+                         .PLLOUTCORE     (pixclk),
+                         .BYPASS         (1'b0),
+                         .RESETB         (1'b1)
+                  );
+
+  // Use counter logic to divide system clock.  The clock is 48 MHz,
+  // so we divide it down by 2^28.
+  reg [10:0] counter_x = 0;
+  reg [10:0] counter_y = 0;
+
+  // 800 840 968 1056 600 601 605 628 @ 40MHz
+  
+  localparam HS_START = 16;
+  localparam HS_END = 16+(968-840);
+  localparam H_TOTAL = 1056;
+  
+  localparam VS_START = 601;
+  localparam VS_END = 605;
+  localparam V_TOTAL = 628;
+  
+  assign hs = ~((counter_x >= HS_START) & (counter_x < HS_END));
+  assign vs = ~((counter_y >= VS_START) & (counter_y < VS_END));
+
+  always @(posedge vs) begin
+     counter <= counter + 1;
+  end
+
+  always @(posedge pixclk) begin
+    if (counter_x < H_TOTAL)
+      counter_x <= counter_x + 1;
+    else begin
+      counter_x <= 0;
+      if (counter_y < V_TOTAL)
+        counter_y <= counter_y + 1;
+      else
+        counter_y <= 0;
+    end
+
+    if (counter_x>300 && counter_x<400 && counter_y>200 && counter_y<300)
+      pixel = 1;
+    else
+      pixel = 0;
+  end
+
+  // Instantiate iCE40 LED driver hard logic, connecting up
+  // latched button state, 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 RGBA_DRIVER (
+                           .CURREN(1'b1),
+                           .RGBLEDEN(1'b1),
+                           .RGB0PWM(counter[8]), // red
+                           .RGB1PWM(counter[9]), // green			   
+                           .RGB2PWM(counter[10]), // blue  
+                           .RGB0(rgb0),
+                           .RGB1(rgb1),
+                           .RGB2(rgb2)
+  );
+
+  // Parameters from iCE40 UltraPlus LED Driver Usage Guide, pages 19-20
+  localparam RGBA_CURRENT_MODE_FULL = "0b0";
+  localparam RGBA_CURRENT_MODE_HALF = "0b1";
+
+  // Current levels in Full / Half mode
+  localparam RGBA_CURRENT_04MA_02MA = "0b000001";
+  localparam RGBA_CURRENT_08MA_04MA = "0b000011";
+  localparam RGBA_CURRENT_12MA_06MA = "0b000111";
+  localparam RGBA_CURRENT_16MA_08MA = "0b001111";
+  localparam RGBA_CURRENT_20MA_10MA = "0b011111";
+  localparam RGBA_CURRENT_24MA_12MA = "0b111111";
+
+  // Set parameters of RGBA_DRIVER (output current)
+  //
+  // Mapping of RGBn to LED colours determined experimentally
+  defparam RGBA_DRIVER.CURRENT_MODE = RGBA_CURRENT_MODE_HALF;
+  defparam RGBA_DRIVER.RGB0_CURRENT = RGBA_CURRENT_16MA_08MA;  // Blue - Needs more current.
+  defparam RGBA_DRIVER.RGB1_CURRENT = RGBA_CURRENT_08MA_04MA;  // Red
+  defparam RGBA_DRIVER.RGB2_CURRENT = RGBA_CURRENT_08MA_04MA;  // Green
+
+endmodule