// ***************************************************************************
// ***************************************************************************
// Copyright 2011(c) Analog Devices, Inc.
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// ***************************************************************************
// ***************************************************************************
// ***************************************************************************
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// Transmit HDMI, RGB to CrYCb conversion
// The multiplication coefficients are in 1.4.12 format
// The addition coefficients are in 1.12.12 format
// Cr = (+112.439/256)*R + (-094.154/256)*G + (-018.285/256)*B + 128;
// Y  = (+065.738/256)*R + (+129.057/256)*G + (+025.064/256)*B +  16;
// Cb = (-037.945/256)*R + (-074.494/256)*G + (+112.439/256)*B + 128;

module ad_csc_RGB2CrYCb #(

  parameter   DELAY_DATA_WIDTH = 16) (

  // R-G-B inputs

  input                   clk,
  input       [DW:0]      RGB_sync,
  input       [23:0]      RGB_data,

  // Cr-Y-Cb outputs

  output      [DW:0]      CrYCb_sync,
  output      [23:0]      CrYCb_data);

  localparam  DW = DELAY_DATA_WIDTH - 1;

  // Cr (red-diff)

  ad_csc_1 #(.DELAY_DATA_WIDTH(DELAY_DATA_WIDTH)) i_csc_1_Cr (
    .clk (clk),
    .sync (RGB_sync),
    .data (RGB_data),
    .C1 (17'h00707),
    .C2 (17'h105e2),
    .C3 (17'h10124),
    .C4 (25'h0080000),
    .csc_sync_1 (CrYCb_sync),
    .csc_data_1 (CrYCb_data[23:16]));

  // Y (luma)

  ad_csc_1 #(.DELAY_DATA_WIDTH(1)) i_csc_1_Y (
    .clk (clk),
    .sync (1'd0),
    .data (RGB_data),
    .C1 (17'h0041b),
    .C2 (17'h00810),
    .C3 (17'h00191),
    .C4 (25'h0010000),
    .csc_sync_1 (),
    .csc_data_1 (CrYCb_data[15:8]));

  // Cb (blue-diff)

  ad_csc_1 #(.DELAY_DATA_WIDTH(1)) i_csc_1_Cb (
    .clk (clk),
    .sync (1'd0),
    .data (RGB_data),
    .C1 (17'h1025f),
    .C2 (17'h104a7),
    .C3 (17'h00707),
    .C4 (25'h0080000),
    .csc_sync_1 (),
    .csc_data_1 (CrYCb_data[7:0]));

endmodule

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