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