Subversion Repositories djpeg

//---------------------------------------------------------------------------

// File Name   : jpeg_dht.v

// Module Name : jpeg_dht

// Description : DHT space

// Project     : JPEG Decoder

// Belong to   : 

// Author      : H.Ishihara

// E-Mail      : hidemi@sweetcafe.jp

// HomePage    : http://www.sweetcafe.jp/

// Date        : 2006/10/01

// Rev.        : 1.1

//---------------------------------------------------------------------------

// Rev. Date       Description

//---------------------------------------------------------------------------

// 1.01 2006/10/01 1st Release

//---------------------------------------------------------------------------

// $Id: 

//---------------------------------------------------------------------------

`timescale 1ps / 1ps

module jpeg_dht

  (

   rst,

   clk,

   DataInEnable,

   DataInColor,

   DataInCount,

   DataIn,

   ColorNumber,

   TableNumber,

   ZeroTable,

   WidhtTable

   );

   input        rst;

   input        clk;

   input        DataInEnable;

   input [1:0]   DataInColor;

   input [7:0]   DataInCount;

   input [7:0] DataIn;

   input [1:0]   ColorNumber;

   input [7:0]  TableNumber;

   output [3:0] ZeroTable;

   output [3:0] WidhtTable;

   // RAM

   reg [7:0]    DHT_Ydc [0:15];

   reg [7:0]    DHT_Yac [0:255];

   reg [7:0]    DHT_Cdc [0:15];

   reg [7:0]    DHT_Cac [0:255];

   reg [7:0]     ReadDataYdc;

   reg [7:0]     ReadDataYac;

   reg [7:0]     ReadDataCdc;

   reg [7:0]     ReadDataCac;

   wire [7:0]    ReadData;

   // RAM

   always @(posedge clk) begin

      if(DataInEnable ==1'b1 & DataInColor ==2'b00) begin

         DHT_Ydc[DataInCount[3:0]] <= DataIn;

      end

      if(DataInEnable ==1'b1 & DataInColor ==2'b01) begin

         DHT_Yac[DataInCount] <= DataIn;

      end

      if(DataInEnable ==1'b1 & DataInColor ==2'b10) begin

         DHT_Cdc[DataInCount[3:0]] <= DataIn;

      end

      if(DataInEnable ==1'b1 & DataInColor ==2'b11) begin

         DHT_Cac[DataInCount] <= DataIn;

      end

   end // always @ (posedge clk)

   always @(posedge clk) begin

      ReadDataYdc <= DHT_Ydc[TableNumber[3:0]];

      ReadDataYac <= DHT_Yac[TableNumber];

      ReadDataCdc <= DHT_Cdc[TableNumber[3:0]];

      ReadDataCac <= DHT_Cac[TableNumber];

   end // always @ (posedge clk or negedge rst)

   // Selector

/*

   always @(*) begin

      case (ColorNumber)

        2'b00: ReadData <= ReadDataYdc;

        2'b01: ReadData <= ReadDataYac;

        2'b10: ReadData <= ReadDataCdc;

        2'b11: ReadData <= ReadDataCac;

      endcase // case(ColorNumber)

   end

*/

        function [7:0] ReadDataSel;

                input [1:0]      ColorNumber;

                input [7:0]      ReadDataYdc;

                input [7:0]      ReadDataYac;

                input [7:0]      ReadDataCdc;

                input [7:0]      ReadDataCac;

        begin

                case (ColorNumber)

                2'b00: ReadDataSel = ReadDataYdc;

                2'b01: ReadDataSel = ReadDataYac;

                2'b10: ReadDataSel = ReadDataCdc;

                2'b11: ReadDataSel = ReadDataCac;

                endcase

        end

        endfunction

   assign ReadData = ReadDataSel(ColorNumber, ReadDataYdc, ReadDataYac, ReadDataCdc, ReadDataCac);

   assign ZeroTable  = ReadData[7:4];

   assign WidhtTable = ReadData[3:0];

endmodule // jpeg_dht