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More generic code for specifying modes.

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Three different modes (640x480, 1024x768, 1280x1024)
This commit is contained in:
Bruno Levy
2021-03-30 19:52:24 +02:00
parent 90f59ee3e8
commit 7ef5694877
2 changed files with 106 additions and 39 deletions
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2
Basic/FOMU_VGA/makeit.sh
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@@ -1,4 +1,4 @@
rm -fr vga.bit vga.dfu vga.asc
rm -fr vga.bit vga.dfu vga.asc vga.json
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

143
Basic/FOMU_VGA/vga.v
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@@ -27,9 +27,12 @@ module vga (
wire pixel_clk;
// PLL: converts system clock (48 MHz)
// to pixel clock (25.125 MHz for 640x480)
// Values obtained using:
//`define VGA_MODE_640x480
//`define VGA_MODE_1024x768
`define VGA_MODE_1280x1024
`ifdef VGA_MODE_640x480
// PLL: converts system clock (48 MHz) to pixel clock (25.125 MHz for 640x480)
// icepll -i 48 -o 25.125
SB_PLL40_CORE #(
.FEEDBACK_PATH("SIMPLE"),
@@ -44,61 +47,125 @@ module vga (
.RESETB (1'b1)
);
// video structure constants
parameter width = 640;
parameter height = 480;
parameter h_front_porch = 16;
parameter h_sync_width = 96;
parameter h_back_porch = 48;
parameter v_front_porch = 11;
parameter v_sync_width = 2;
parameter v_back_porch = 28;
// Video mode constants
parameter VGA_width = 640;
parameter VGA_height = 480;
parameter VGA_h_front_porch = 16;
parameter VGA_h_sync_width = 96;
parameter VGA_h_back_porch = 48;
parameter VGA_v_front_porch = 10;
parameter VGA_v_sync_width = 2;
parameter VGA_v_back_porch = 32;
`endif
reg [9:0] X, Y; // current pixel coordinates
reg hSync, vSync; // horizontal and vertical synchronization
reg DrawArea; // asserted if current pixel is in drawing area
reg [15:0] frame; // frame counter
`ifdef VGA_MODE_1024x768
// PLL: converts system clock (48 MHz) to pixel clock (65 MHz for 1024x768)
// icepll -i 48 -o 65
SB_PLL40_CORE #(
.FEEDBACK_PATH("SIMPLE"),
.DIVR(4'b0010),
.DIVF(7'b1000000),
.DIVQ(3'b100),
.FILTER_RANGE(3'b001),
) pll (
.REFERENCECLK (clki),
.PLLOUTCORE (pixel_clk),
.BYPASS (1'b0),
.RESETB (1'b1)
);
// Video mode constants
parameter VGA_width = 1024;
parameter VGA_height = 768;
parameter VGA_h_front_porch = 24;
parameter VGA_h_sync_width = 136;
parameter VGA_h_back_porch = 160;
parameter VGA_v_front_porch = 3;
parameter VGA_v_sync_width = 6;
parameter VGA_v_back_porch = 29;
`endif
`ifdef VGA_MODE_1280x1024
// PLL: converts system clock (48 MHz) to pixel clock (108 MHz for 1280x1024)
// icepll -i 48 -o 108
SB_PLL40_CORE #(
.FEEDBACK_PATH("SIMPLE"),
.DIVR(4'b0000),
.DIVF(7'b0010001),
.DIVQ(3'b011),
.FILTER_RANGE(3'b100),
) pll (
.REFERENCECLK (clki),
.PLLOUTCORE (pixel_clk),
.BYPASS (1'b0),
.RESETB (1'b1)
);
// Video mode constants
parameter VGA_width = 1280;
parameter VGA_height = 1024;
parameter VGA_h_front_porch = 48;
parameter VGA_h_sync_width = 112;
parameter VGA_h_back_porch = 248;
parameter VGA_v_front_porch = 1;
parameter VGA_v_sync_width = 3;
parameter VGA_v_back_porch = 38;
`endif
parameter VGA_line_width = VGA_width + VGA_h_front_porch + VGA_h_sync_width + VGA_h_back_porch;
parameter VGA_lines = VGA_height + VGA_v_front_porch + VGA_v_sync_width + VGA_v_back_porch;
reg [11:0] VGA_X, VGA_Y; // current pixel coordinates
reg VGA_hSync, VGA_vSync; // horizontal and vertical synchronization
reg VGA_DrawArea; // asserted if current pixel is in drawing area
reg [15:0] VGA_frame; // frame counter
always @(posedge pixel_clk) begin
DrawArea <= (X<640) && (Y<480);
X <= (X==799) ? 0 : X+1;
if(X==799) begin
if(Y==524) begin
Y <= 0;
frame <= frame + 1;
VGA_DrawArea <= (VGA_X<VGA_width) && (VGA_Y<VGA_height);
if(VGA_X==VGA_line_width-1) begin
VGA_X <= 0;
if(VGA_Y==VGA_lines-1) begin
VGA_Y <= 0;
VGA_frame <= VGA_frame + 1;
end else begin
Y <= Y+1;
VGA_Y <= VGA_Y+1;
end
end else begin
VGA_X <= VGA_X + 1;
end
hSync <= (X>=656) && (X<752);
vSync <= (Y>=490) && (Y<492);
VGA_hSync <= (VGA_X>=VGA_width+VGA_h_front_porch) && (VGA_X<VGA_width+VGA_h_front_porch+VGA_h_sync_width);
VGA_vSync <= (VGA_Y>=VGA_height+VGA_v_front_porch) && (VGA_Y<VGA_height+VGA_v_front_porch+VGA_v_sync_width);
end
wire [1:0] out_color;
wire signed [9:0] dx = $signed(X) - 320;
wire signed [9:0] dy = $signed(Y) - 240;
wire signed [15:0] R2 = dx*dx + dy*dy - $signed(frame << 6);
wire signed [11:0] dx = $signed(VGA_X) - VGA_width/2;
wire signed [11:0] dy = $signed(VGA_Y) - VGA_height/2;
wire signed [15:0] R2 = dx*dx + dy*dy - $signed(VGA_frame << 6);
assign out_color = DrawArea ? {R2[12],R2[13]} : 2'b00;
assign out_color = VGA_DrawArea ? {R2[12],R2[13]} : 2'b00;
assign user_1 = hSync;
assign user_2 = vSync;
assign user_1 = VGA_hSync;
assign user_2 = VGA_vSync;
assign user_3 = out_color[0];
assign user_4 = out_color[1];
// LED driver
// Note: the LED driver is more intelligent than I wish, it changes color
// at the same frequency whatever the bit of frame I'm using, I need to
// understand what's going on here (supposed to be a PWM, maybe I should
// generate pulses of varying length to control intensity of r,g,b...)
SB_RGBA_DRV #(
.CURRENT_MODE("0b1"), // half current mode
.CURRENT_MODE("0b1"), // half current mode
.RGB0_CURRENT("0b001111"), // Blue - Needs more current.
.RGB1_CURRENT("0b000011"), // Red
.RGB2_CURRENT("0b000011"), // Green
) led_driver(
.RGB2_CURRENT("0b000011") // Green
) led_driver (
.CURREN(1'b1),
.RGBLEDEN(1'b1),
.RGB0PWM(frame[3]), // red
.RGB1PWM(frame[4]), // green
.RGB2PWM(frame[5]), // blue
.RGB0PWM(VGA_frame[3]), // red
.RGB1PWM(VGA_frame[4]), // green
.RGB2PWM(VGA_frame[5]), // blue
.RGB0(rgb0),
.RGB1(rgb1),
.RGB2(rgb2)