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Refactor video attributes #31

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Refactor video attributes #31

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1 change: 1 addition & 0 deletions src/Manifest.py
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Original file line number Diff line number Diff line change
@@ -1,5 +1,6 @@
files = [
"hdmi.sv",
"hdmi_attr.sv",
"tmds_channel.sv",
"packet_assembler.sv",
"packet_picker.sv",
Expand Down
177 changes: 45 additions & 132 deletions src/hdmi.sv
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Original file line number Diff line number Diff line change
@@ -1,13 +1,21 @@
// Implementation of HDMI Spec v1.4a
// By Sameer Puri https://github.com/sameer

import hdmi_attr::*;

module hdmi
#(
// Defaults to 640x480 which should be supported by almost if not all HDMI sinks.
// See README.md or CEA-861-D for enumeration of video id codes.
// Pixel repetition, interlaced scans and other special output modes are not implemented (yet).
parameter int VIDEO_ID_CODE = 1,

// Basic video attributes.
//
// Derived from VIDEO_ID_CODE by default. Only override if you know what
// you're doing.
parameter video_attr_t VIDEO_ATTR = video_attr_for_id(VIDEO_ID_CODE),

// The IT content bit indicates that image samples are generated in an ad-hoc
// manner (e.g. directly from values in a framebuffer, as by a PC video
// card) and therefore aren't suitable for filtering or analog
Expand All @@ -21,8 +29,8 @@ module hdmi

// 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 = $clog2(VIDEO_ATTR.frame_width),
parameter int BIT_HEIGHT = $clog2(VIDEO_ATTR.frame_height),

// 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 @@ -79,136 +87,41 @@ module hdmi
// They are used (by you) to pick the color each pixel should have
// i.e. always_ff @(posedge pixel_clk) rgb <= {8'd0, 8'(cx), 8'(cy)};
output logic [BIT_WIDTH-1:0] cx = START_X,
output logic [BIT_HEIGHT-1:0] cy = START_Y,

// The screen is at the upper left corner of the frame.
// 0,0 = 0,0 in video
// the frame includes extra space for sending auxiliary data
output logic [BIT_WIDTH-1:0] frame_width,
output logic [BIT_HEIGHT-1:0] frame_height,
output logic [BIT_WIDTH-1:0] screen_width,
output logic [BIT_HEIGHT-1:0] screen_height
output logic [BIT_HEIGHT-1:0] cy = START_Y
);

localparam int NUM_CHANNELS = 3;
logic hsync;
logic vsync;
localparam int FRAME_WIDTH = VIDEO_ATTR.frame_width;
localparam int FRAME_HEIGHT = VIDEO_ATTR.frame_height;
localparam int SCREEN_WIDTH = VIDEO_ATTR.screen_width;
localparam int SCREEN_HEIGHT = VIDEO_ATTR.screen_height;
localparam int HSYNC_PULSE_START = VIDEO_ATTR.hsync_pulse_start;
localparam int HSYNC_PULSE_SIZE = VIDEO_ATTR.hsync_pulse_size;
localparam int VSYNC_PULSE_START = VIDEO_ATTR.vsync_pulse_start;
localparam int VSYNC_PULSE_SIZE = VIDEO_ATTR.vsync_pulse_size;
localparam logic INVERT = VIDEO_ATTR.invert;
localparam real BASE_PIXEL_CLOCK = VIDEO_ATTR.base_pixel_clock;
localparam real VIDEO_RATE = BASE_PIXEL_CLOCK * (
(VIDEO_REFRESH_RATE == 59.94 || VIDEO_REFRESH_RATE == 29.97) ?
1000.0/1001.0 :
1
); // https://groups.google.com/forum/#!topic/sci.engr.advanced-tv/DQcGk5R_zsM

logic [BIT_WIDTH-1:0] hsync_pulse_start, hsync_pulse_size;
logic [BIT_HEIGHT-1:0] vsync_pulse_start, vsync_pulse_size;
logic invert;
localparam int NUM_CHANNELS = 3;

// See CEA-861-D for more specifics formats described below.
generate
case (VIDEO_ID_CODE)
1:
begin
assign frame_width = 800;
assign frame_height = 525;
assign screen_width = 640;
assign screen_height = 480;
assign hsync_pulse_start = 16;
assign hsync_pulse_size = 96;
assign vsync_pulse_start = 10;
assign vsync_pulse_size = 2;
assign invert = 1;
end
2, 3:
begin
assign frame_width = 858;
assign frame_height = 525;
assign screen_width = 720;
assign screen_height = 480;
assign hsync_pulse_start = 16;
assign hsync_pulse_size = 62;
assign vsync_pulse_start = 9;
assign vsync_pulse_size = 6;
assign invert = 1;
end
4:
begin
assign frame_width = 1650;
assign frame_height = 750;
assign screen_width = 1280;
assign screen_height = 720;
assign hsync_pulse_start = 110;
assign hsync_pulse_size = 40;
assign vsync_pulse_start = 5;
assign vsync_pulse_size = 5;
assign invert = 0;
end
16, 34:
begin
assign frame_width = 2200;
assign frame_height = 1125;
assign screen_width = 1920;
assign screen_height = 1080;
assign hsync_pulse_start = 88;
assign hsync_pulse_size = 44;
assign vsync_pulse_start = 4;
assign vsync_pulse_size = 5;
assign invert = 0;
end
17, 18:
begin
assign frame_width = 864;
assign frame_height = 625;
assign screen_width = 720;
assign screen_height = 576;
assign hsync_pulse_start = 12;
assign hsync_pulse_size = 64;
assign vsync_pulse_start = 5;
assign vsync_pulse_size = 5;
assign invert = 1;
end
19:
begin
assign frame_width = 1980;
assign frame_height = 750;
assign screen_width = 1280;
assign screen_height = 720;
assign hsync_pulse_start = 440;
assign hsync_pulse_size = 40;
assign vsync_pulse_start = 5;
assign vsync_pulse_size = 5;
assign invert = 0;
end
95, 105, 97, 107:
begin
assign frame_width = 4400;
assign frame_height = 2250;
assign screen_width = 3840;
assign screen_height = 2160;
assign hsync_pulse_start = 176;
assign hsync_pulse_size = 88;
assign vsync_pulse_start = 8;
assign vsync_pulse_size = 10;
assign invert = 0;
end
endcase
endgenerate
logic hsync, vsync;

always_comb begin
hsync <= invert ^ (cx >= screen_width + hsync_pulse_start && cx < screen_width + hsync_pulse_start + hsync_pulse_size);
hsync <= INVERT ^ (cx >= SCREEN_WIDTH + HSYNC_PULSE_START && cx < SCREEN_WIDTH + HSYNC_PULSE_START + HSYNC_PULSE_SIZE);
// vsync pulses should begin and end at the start of hsync, so special
// handling is required for the lines on which vsync starts and ends
if (cy == screen_height + vsync_pulse_start)
vsync <= invert ^ (cx >= screen_width + hsync_pulse_start);
else if (cy == screen_height + vsync_pulse_start + vsync_pulse_size)
vsync <= invert ^ (cx < screen_width + hsync_pulse_start);
if (cy == SCREEN_HEIGHT + VSYNC_PULSE_START)
vsync <= INVERT ^ (cx >= SCREEN_WIDTH + HSYNC_PULSE_START);
else if (cy == SCREEN_HEIGHT + VSYNC_PULSE_START + VSYNC_PULSE_SIZE)
vsync <= INVERT ^ (cx < SCREEN_WIDTH + HSYNC_PULSE_START);
else
vsync <= invert ^ (cy >= screen_height + vsync_pulse_start && cy < screen_height + vsync_pulse_start + vsync_pulse_size);
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
: VIDEO_ID_CODE == 2 || VIDEO_ID_CODE == 3 ? 27.027E6
: VIDEO_ID_CODE == 4 ? 74.25E6
: VIDEO_ID_CODE == 16 ? 148.5E6
: VIDEO_ID_CODE == 17 || VIDEO_ID_CODE == 18 ? 27E6
: VIDEO_ID_CODE == 19 ? 74.25E6
: VIDEO_ID_CODE == 34 ? 74.25E6
: VIDEO_ID_CODE == 95 || VIDEO_ID_CODE == 105 || VIDEO_ID_CODE == 97 || VIDEO_ID_CODE == 107 ? 594E6
: 0) * (VIDEO_REFRESH_RATE == 59.94 || VIDEO_REFRESH_RATE == 29.97 ? 1000.0/1001.0 : 1); // https://groups.google.com/forum/#!topic/sci.engr.advanced-tv/DQcGk5R_zsM

// Wrap-around pixel position counters indicating the pixel to be generated by the user in THIS clock and sent out in the NEXT clock.
always_ff @(posedge clk_pixel)
Expand All @@ -220,8 +133,8 @@ begin
end
else
begin
cx <= cx == frame_width-1'b1 ? BIT_WIDTH'(0) : cx + 1'b1;
cy <= cx == frame_width-1'b1 ? cy == frame_height-1'b1 ? BIT_HEIGHT'(0) : cy + 1'b1 : cy;
cx <= cx == FRAME_WIDTH-1'b1 ? BIT_WIDTH'(0) : cx + 1'b1;
cy <= cx == FRAME_WIDTH-1'b1 ? cy == FRAME_HEIGHT-1'b1 ? BIT_HEIGHT'(0) : cy + 1'b1 : cy;
end
end

Expand All @@ -232,7 +145,7 @@ begin
if (reset)
video_data_period <= 0;
else
video_data_period <= cx < screen_width && cy < screen_height;
video_data_period <= cx < SCREEN_WIDTH && cy < SCREEN_HEIGHT;
end

logic [2:0] mode = 3'd1;
Expand All @@ -254,8 +167,8 @@ generate
end
else
begin
video_guard <= cx >= frame_width - 2 && cx < frame_width && (cy == frame_height - 1 || cy < screen_height);
video_preamble <= cx >= frame_width - 10 && cx < frame_width - 2 && (cy == frame_height - 1 || cy < screen_height);
video_guard <= cx >= FRAME_WIDTH - 2 && cx < FRAME_WIDTH && (cy == FRAME_HEIGHT - 1 || cy < SCREEN_HEIGHT);
video_preamble <= cx >= FRAME_WIDTH - 10 && cx < FRAME_WIDTH - 2 && (cy == FRAME_HEIGHT - 1 || cy < SCREEN_HEIGHT);
end
end

Expand All @@ -264,17 +177,17 @@ generate
logic [4:0] num_packets_alongside;
always_comb
begin
max_num_packets_alongside = ((frame_width - screen_width) /* VD period */ - 2 /* V guard */ - 8 /* V preamble */ - 12 /* 12px control period */ - 2 /* DI guard */ - 2 /* DI start guard */ - 8 /* DI premable */) / 32;
max_num_packets_alongside = ((FRAME_WIDTH - SCREEN_WIDTH) /* VD period */ - 2 /* V guard */ - 8 /* V preamble */ - 12 /* 12px control period */ - 2 /* DI guard */ - 2 /* DI start guard */ - 8 /* DI premable */) / 32;
if (max_num_packets_alongside > 18)
num_packets_alongside = 5'd18;
else
num_packets_alongside = 5'(max_num_packets_alongside);
end

logic data_island_period_instantaneous;
assign data_island_period_instantaneous = num_packets_alongside > 0 && cx >= screen_width + 10 && cx < screen_width + 10 + num_packets_alongside * 32;
assign data_island_period_instantaneous = num_packets_alongside > 0 && cx >= SCREEN_WIDTH + 10 && cx < SCREEN_WIDTH + 10 + num_packets_alongside * 32;
logic packet_enable;
assign packet_enable = data_island_period_instantaneous && 5'(cx + screen_width + 22) == 5'd0;
assign packet_enable = data_island_period_instantaneous && 5'(cx + SCREEN_WIDTH + 22) == 5'd0;

logic data_island_guard = 0;
logic data_island_preamble = 0;
Expand All @@ -289,8 +202,8 @@ generate
end
else
begin
data_island_guard <= num_packets_alongside > 0 && ((cx >= screen_width + 8 && cx < screen_width + 10) || (cx >= screen_width + 10 + num_packets_alongside * 32 && cx < screen_width + 10 + num_packets_alongside * 32 + 2));
data_island_preamble <= num_packets_alongside > 0 && cx >= screen_width && cx < screen_width + 8;
data_island_guard <= num_packets_alongside > 0 && ((cx >= SCREEN_WIDTH + 8 && cx < SCREEN_WIDTH + 10) || (cx >= SCREEN_WIDTH + 10 + num_packets_alongside * 32 && cx < SCREEN_WIDTH + 10 + num_packets_alongside * 32 + 2));
data_island_preamble <= num_packets_alongside > 0 && cx >= SCREEN_WIDTH && cx < SCREEN_WIDTH + 8;
data_island_period <= data_island_period_instantaneous;
end
end
Expand All @@ -299,7 +212,7 @@ generate
logic [23:0] header;
logic [55:0] sub [3:0];
logic video_field_end;
assign video_field_end = cx == screen_width - 1'b1 && cy == screen_height - 1'b1;
assign video_field_end = cx == SCREEN_WIDTH - 1'b1 && cy == SCREEN_HEIGHT - 1'b1;
logic [4:0] packet_pixel_counter;
packet_picker #(
.VIDEO_ID_CODE(VIDEO_ID_CODE),
Expand Down
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