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move screen to upper left corner in frame. this way, origin = screen …
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@sameer
sameer committed Mar 6, 2021
1 parent 6198647 commit 97e098f
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Showing 3 changed files with 61 additions and 40 deletions.
91 changes: 57 additions & 34 deletions src/hdmi.sv
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Original file line number Diff line number Diff line change
Expand Up @@ -53,22 +53,24 @@ module hdmi
// i.e. always_ff @(posedge pixel_clk) rgb <= {8'd0, 8'(cx), 8'(cy)};
output logic [BIT_WIDTH-1:0] cx = BIT_WIDTH'(0),
output logic [BIT_HEIGHT-1:0] cy = BIT_HEIGHT'(0),
// the screen is at the bottom right corner of the frame, namely:
// frame_width = screen_start_x + screen_width
// frame_height = screen_start_y + screen_height

// 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_WIDTH-1:0] screen_start_x,
output logic [BIT_HEIGHT-1:0] screen_start_y
output logic [BIT_HEIGHT-1:0] screen_height
);

localparam int NUM_CHANNELS = 3;
logic hsync;
logic vsync;

logic [BIT_WIDTH-1:0] hsync_porch_start, hsync_porch_size;
logic [BIT_HEIGHT-1:0] vsync_porch_start, vsync_porch_size;
logic invert;

// See CEA-861-D for more specifics formats described below.
generate
case (VIDEO_ID_CODE)
Expand All @@ -78,66 +80,87 @@ generate
assign frame_height = 525;
assign screen_width = 640;
assign screen_height = 480;
assign hsync = ~(cx >= 16 && cx < 16 + 96);
assign vsync = ~(cy >= 10 && cy < 10 + 2);
assign hsync_porch_start = 16;
assign hsync_porch_size = 96;
assign vsync_porch_start = 10;
assign vsync_porch_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 = ~(cx >= 16 && cx < 16 + 62);
assign vsync = ~(cy >= 9 && cy < 9 + 6);
assign hsync_porch_start = 16;
assign hsync_porch_size = 62;
assign vsync_porch_start = 9;
assign vsync_porch_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 = cx >= 110 && cx < 110 + 40;
assign vsync = cy >= 5 && cy < 5 + 5;
assign hsync_porch_start = 110;
assign hsync_porch_size = 40;
assign vsync_porch_start = 5;
assign vsync_porch_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 = cx >= 88 && cx < 88 + 44;
assign vsync = cy >= 4 && cy < 4 + 5;
assign hsync_porch_start = 88;
assign hsync_porch_size = 44;
assign vsync_porch_start = 4;
assign vsync_porch_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 = ~(cx >= 12 && cx < 12 + 64);
assign vsync = ~(cy >= 5 && cy < 5 + 5);
assign hsync_porch_start = 12;
assign hsync_porch_size = 64;
assign vsync_porch_start = 5;
assign vsync_porch_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 = cx >= 440 && cx < 440 + 40;
assign vsync = cy >= 5 && cy < 5 + 5;
assign hsync_porch_start = 440;
assign hsync_porch_size = 40;
assign vsync_porch_start = 5;
assign vsync_porch_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 = cx >= 176 && cx < 176 + 88;
assign vsync = cy >= 8 && cy < 8 + 10;
assign hsync_porch_start = 176;
assign hsync_porch_size = 88;
assign vsync_porch_start = 8;
assign vsync_porch_size = 10;
assign invert = 0;
end
endcase
assign screen_start_x = frame_width - screen_width;
assign screen_start_y = frame_height - screen_height;
assign hsync = invert ^ (cx >= screen_width + hsync_porch_start && cx < screen_width + hsync_porch_start + hsync_porch_size);
assign vsync = invert ^ (cy >= screen_height + vsync_porch_start && cy < screen_height + vsync_porch_start + vsync_porch_size);
endgenerate

localparam real VIDEO_RATE = (VIDEO_ID_CODE == 1 ? 25.2E6
Expand All @@ -158,9 +181,9 @@ begin
end

// See Section 5.2
logic video_data_period = 1;
logic video_data_period = 0;
always_ff @(posedge clk_pixel)
video_data_period <= cx >= screen_start_x && cy >= screen_start_y;
video_data_period <= cx < screen_width && cy < screen_height;

logic [2:0] mode = 3'd1;
logic [23:0] video_data = 24'd0;
Expand All @@ -174,42 +197,42 @@ generate
logic video_preamble = 0;
always_ff @(posedge clk_pixel)
begin
video_guard <= cx >= screen_start_x - 2 && cx < screen_start_x && cy >= screen_start_y;
video_preamble <= cx >= screen_start_x - 10 && cx < screen_start_x - 2 && cy >= screen_start_y;
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

// See Section 5.2.3.1
int max_num_packets_alongside;
logic [4:0] num_packets_alongside;
always_comb
begin
max_num_packets_alongside = (screen_start_x /* 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 >= 10 && cx < 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 + 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;
logic data_island_period = 0;
always_ff @(posedge clk_pixel)
begin
data_island_guard <= num_packets_alongside > 0 && ((cx >= 8 && cx < 10) || (cx >= 10 + num_packets_alongside * 32 && cx < 10 + num_packets_alongside * 32 + 2));
data_island_preamble <= num_packets_alongside > 0 && /* cx >= 0 && */ cx < 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

// See Section 5.2.3.4
logic [23:0] header;
logic [55:0] sub [3:0];
logic video_field_end;
assign video_field_end = cx == frame_width - 1'b1 && cy == frame_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 All @@ -230,7 +253,7 @@ generate
video_data <= rgb;
control_data <= {{1'b0, data_island_preamble}, {1'b0, video_preamble || data_island_preamble}, {vsync, hsync}}; // ctrl3, ctrl2, ctrl1, ctrl0, vsync, hsync
data_island_data[11:4] <= packet_data[8:1];
data_island_data[3] <= cx != screen_start_x;
data_island_data[3] <= cx != 0;
data_island_data[2] <= packet_data[0];
data_island_data[1:0] <= {vsync, hsync};
end
Expand Down
6 changes: 3 additions & 3 deletions test/top_tb/top_tb.sv
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Original file line number Diff line number Diff line change
Expand Up @@ -110,13 +110,13 @@ always @(posedge top.clk_pixel)
begin
cx <= cx == top.frame_width - 1 ? 0 : cx + 1;
cy <= cx == top.frame_width-1'b1 ? cy == top.frame_height-1'b1 ? 0 : cy + 1'b1 : cy;
if (top.hdmi.true_hdmi_output.num_packets_alongside > 0 && (cx >= 8 && cx < 10) || (cx >= 10 + top.hdmi.true_hdmi_output.num_packets_alongside * 32 && cx < 10 + top.hdmi.true_hdmi_output.num_packets_alongside * 32 + 2))
if (top.hdmi.true_hdmi_output.num_packets_alongside > 0 && (cx >= top.screen_width + 8 && cx < top.screen_width + 10) || (cx >= top.screen_width + 10 + top.hdmi.true_hdmi_output.num_packets_alongside * 32 && cx < top.screen_width + 10 + top.hdmi.true_hdmi_output.num_packets_alongside * 32 + 2))
begin
assert(tmds_values[2] == 10'b0100110011) else $fatal("Channel 2 DI GB incorrect: %b", tmds_values[2]);
assert(tmds_values[1] == 10'b0100110011) else $fatal("Channel 1 DI GB incorrect");
assert(tmds_values[0] == 10'b1010001110 || tmds_values[0] == 10'b1001110001 || tmds_values[0] == 10'b0101100011 || tmds_values[0] == 10'b1011000011) else $fatal("Channel 0 DI GB incorrect");
end
else if (top.hdmi.true_hdmi_output.num_packets_alongside > 0 && cx >= 10 && cx < 10 + top.hdmi.true_hdmi_output.num_packets_alongside * 32)
else if (top.hdmi.true_hdmi_output.num_packets_alongside > 0 && cx >= top.screen_width + 10 && cx < top.screen_width + 10 + top.hdmi.true_hdmi_output.num_packets_alongside * 32)
begin
data_counter <= data_counter + 1'd1;
if (data_counter == 0)
Expand All @@ -126,7 +126,7 @@ begin
sub[1][63:1] <= 63'dX;
sub[0][63:1] <= 63'dX;
header[31:1] <= 31'dX;
if (cx != 10 || !first_packet) // Packet complete
if (cx != top.screen_width + 10 || !first_packet) // Packet complete
begin
first_packet <= 0;
case(header[7:0])
Expand Down
4 changes: 1 addition & 3 deletions top/top.sv
View file
Original file line number Diff line number Diff line change
Expand Up @@ -16,7 +16,7 @@ logic [23:0] rgb = 24'd0;
logic [9:0] cx, cy, screen_start_x, screen_start_y, frame_width, frame_height, screen_width, screen_height;
// Border test (left = red, top = green, right = blue, bottom = blue, fill = black)
always @(posedge clk_pixel)
rgb <= {cx == screen_start_x ? ~8'd0 : 8'd0, cy == screen_start_y ? ~8'd0 : 8'd0, cx == frame_width - 1'd1 || cy == frame_height - 1'd1 ? ~8'd0 : 8'd0};
rgb <= {cx == 0 ? ~8'd0 : 8'd0, cy == 0 ? ~8'd0 : 8'd0, cx == screen_width - 1'd1 || cy == screen_width - 1'd1 ? ~8'd0 : 8'd0};

// 640x480 @ 59.94Hz
hdmi #(.VIDEO_ID_CODE(1), .VIDEO_REFRESH_RATE(59.94), .AUDIO_RATE(48000), .AUDIO_BIT_WIDTH(16)) hdmi(
Expand All @@ -29,8 +29,6 @@ hdmi #(.VIDEO_ID_CODE(1), .VIDEO_REFRESH_RATE(59.94), .AUDIO_RATE(48000), .AUDIO
.tmds_clock(tmds_clock),
.cx(cx),
.cy(cy),
.screen_start_x(screen_start_x),
.screen_start_y(screen_start_y),
.frame_width(frame_width),
.frame_height(frame_height),
.screen_width(screen_width),
Expand Down

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