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Add custom video mode with video id code 0 #45

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Add custom video mode with video id code 0 #45

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34 changes: 31 additions & 3 deletions src/hdmi.sv
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Original file line number Diff line number Diff line change
Expand Up @@ -18,11 +18,25 @@ module hdmi
// This flag also tends to cause receivers to treat RGB values as full
// range (0-255).
parameter bit IT_CONTENT = 1'b1,

// Video parameters for custom video mode (VIDEO_ID_CODE 0)
parameter int CUSTOM_FRAME_WIDTH = 1650,
parameter int CUSTOM_FRAME_HEIGHT = 750,
parameter int CUSTOM_SCREEN_WIDTH = 1280,
parameter int CUSTOM_SCREEN_HEIGHT = 720,
parameter int CUSTOM_HSYNC_PULSE_START = 110,
parameter int CUSTOM_HSYNC_PULSE_SIZE = 40,
parameter int CUSTOM_VSYNC_PULSE_START = 5,
parameter int CUSTOM_VSYNC_PULSE_SIZE = 5,
parameter int CUSTOM_INVERT = 0,
parameter real CUSTOM_VIDEO_RATE = 74.25E6,
parameter int CUSTOM_BIT_WIDTH = 11,
parameter int CUSTOM_BIT_HEIGHT = 10,

// Defaults to minimum bit lengths required to represent positions.
// Modify these parameters if you have alternate desired bit lengths.
parameter int BIT_WIDTH = VIDEO_ID_CODE < 4 ? 10 : VIDEO_ID_CODE == 4 ? 11 : 12,
parameter int BIT_HEIGHT = VIDEO_ID_CODE == 16 ? 11: 10,
parameter int BIT_WIDTH = VIDEO_ID_CODE == 0 ? CUSTOM_BIT_WIDTH : VIDEO_ID_CODE < 4 ? 10 : VIDEO_ID_CODE == 4 ? 11 : 12,
parameter int BIT_HEIGHT = VIDEO_ID_CODE == 0 ? CUSTOM_BIT_HEIGHT : VIDEO_ID_CODE == 16 ? 11: 10,

// A true HDMI signal sends auxiliary data (i.e. audio, preambles) which prevents it from being parsed by DVI signal sinks.
// HDMI signal sinks are fortunately backwards-compatible with DVI signals.
Expand Down Expand Up @@ -101,6 +115,19 @@ logic invert;
// See CEA-861-D for more specifics formats described below.
generate
case (VIDEO_ID_CODE)
0:
begin
// Custom video mode
assign frame_width = CUSTOM_FRAME_WIDTH;
assign frame_height = CUSTOM_FRAME_HEIGHT;
assign screen_width = CUSTOM_SCREEN_WIDTH;
assign screen_height = CUSTOM_SCREEN_HEIGHT;
assign hsync_pulse_start = CUSTOM_HSYNC_PULSE_START;
assign hsync_pulse_size = CUSTOM_HSYNC_PULSE_SIZE;
assign vsync_pulse_start = CUSTOM_VSYNC_PULSE_START;
assign vsync_pulse_size = CUSTOM_VSYNC_PULSE_SIZE;
assign invert = CUSTOM_INVERT;
end
1:
begin
assign frame_width = 800;
Expand Down Expand Up @@ -200,7 +227,8 @@ always_comb begin
vsync <= invert ^ (cy >= screen_height + vsync_pulse_start && cy < screen_height + vsync_pulse_start + vsync_pulse_size);
end

localparam real VIDEO_RATE = (VIDEO_ID_CODE == 1 ? 25.2E6
localparam real VIDEO_RATE = (VIDEO_ID_CODE == 0 ? CUSTOM_VIDEO_RATE
: VIDEO_ID_CODE == 1 ? 25.2E6
: VIDEO_ID_CODE == 2 || VIDEO_ID_CODE == 3 ? 27.027E6
: VIDEO_ID_CODE == 4 ? 74.25E6
: VIDEO_ID_CODE == 16 ? 148.5E6
Expand Down