rec_gclk_gen.v

a H.264/AVC Baseline Decoder

//--------------------------------------------------------------------------------------------------
// Design    : nova
// Author(s) : Ke Xu
// Email	   : [e-mail]
// File      : rec_gclk_gen.v
// Generated : Jan 3, 2006
// Copyright (C) 2008 Ke Xu                
//-------------------------------------------------------------------------------------------------
// Description 
// Gated clock generation module for reconstruction
//-------------------------------------------------------------------------------------------------

// synopsys translate_off
`include "timescale.v"
// synopsys translate_on
`include "nova_defines.v"

module rec_gclk_gen(clk,
	//IQIT
	end_of_NonZeroCoeff_CAVLC,OneD_counter,TwoD_counter,rescale_counter,
	rounding_counter,residual_state,cavlc_decoder_state,
	gclk_1D,gclk_2D,gclk_rescale,gclk_rounding,
	//Intra pred
	mb_num_h,mb_num_v,NextMB_IsSkip,
	mb_type_general,blk4x4_rec_counter,blk4x4_sum_counter,blk4x4_intra_preload_counter,
	blk4x4_intra_precompute_counter,blk4x4_intra_calculate_counter,
	Intra4x4_predmode,Intra16x16_predmode,Intra_chroma_predmode,
	gclk_intra_mbAddrA_luma,gclk_intra_mbAddrA_Cb,gclk_intra_mbAddrA_Cr,
	gclk_intra_mbAddrB,gclk_intra_mbAddrC_luma,gclk_intra_mbAddrD,gclk_seed,
	//Inter pred
	blk4x4_inter_preload_counter,gclk_Inter_ref_rf,
	//sum
	Inter_blk4x4_pred_output_valid,gclk_pred_output,gclk_blk4x4_sum,
	//Deblocking filter
	end_of_MB_DEC,end_of_BS_DEC,DF_duration,
	gclk_end_of_MB_DEC,gclk_DF,
	//memory
	Intra_mbAddrB_RAM_rd,Intra_mbAddrB_RAM_wr,gclk_Intra_mbAddrB_RAM,
	rec_DF_RAM0_cs_n,gclk_rec_DF_RAM0,
	rec_DF_RAM1_cs_n,gclk_rec_DF_RAM1,
	DF_mbAddrA_RF_rd,DF_mbAddrA_RF_wr,gclk_DF_mbAddrA_RF,
	DF_mbAddrB_RAM_rd,DF_mbAddrB_RAM_wr,gclk_DF_mbAddrB_RAM
	);
	input clk;
	//IQIT
	input end_of_NonZeroCoeff_CAVLC;
	input [2:0] OneD_counter;
	input [2:0] TwoD_counter;
	input [2:0] rescale_counter;
	input [2:0] rounding_counter;
	input [3:0] residual_state;
	input [3:0] cavlc_decoder_state;
	output gclk_1D;
	output gclk_2D;
	output gclk_rescale;
	output gclk_rounding;
	//Intra pred
	input [3:0] mb_num_h;
	input [3:0] mb_num_v;
	input NextMB_IsSkip;
	input [3:0] mb_type_general;
	input [4:0] blk4x4_rec_counter;
	input [2:0] blk4x4_sum_counter;
	input [2:0] blk4x4_intra_preload_counter;
	input [3:0] blk4x4_intra_precompute_counter;
	input [2:0] blk4x4_intra_calculate_counter;
	input [3:0] Intra4x4_predmode;
	input [1:0] Intra16x16_predmode;
	input [1:0] Intra_chroma_predmode;
	output gclk_intra_mbAddrA_luma;
	output gclk_intra_mbAddrA_Cb;
	output gclk_intra_mbAddrA_Cr;
	output gclk_intra_mbAddrB; 
	output gclk_intra_mbAddrC_luma;	
	output gclk_intra_mbAddrD;
	output gclk_seed;
	//Inter pred
	input [5:0] blk4x4_inter_preload_counter;
	output gclk_Inter_ref_rf;
	//sum
	input [1:0] Inter_blk4x4_pred_output_valid;
	output gclk_pred_output;
	output gclk_blk4x4_sum;
	//DF
	input end_of_MB_DEC;
	input end_of_BS_DEC;
	input DF_duration;
	output gclk_end_of_MB_DEC;
	output gclk_DF;
	//memory
	input Intra_mbAddrB_RAM_rd;
	input Intra_mbAddrB_RAM_wr;
	output gclk_Intra_mbAddrB_RAM;
	input rec_DF_RAM0_cs_n;
	output gclk_rec_DF_RAM0;
	input rec_DF_RAM1_cs_n;
	output gclk_rec_DF_RAM1;
	input DF_mbAddrA_RF_rd,DF_mbAddrA_RF_wr;
	output gclk_DF_mbAddrA_RF;
	input DF_mbAddrB_RAM_rd,DF_mbAddrB_RAM_wr;
	output gclk_DF_mbAddrB_RAM;
	
	parameter rst_residual		    = 4'b0000;
	parameter Intra16x16DCLevel_s	= 4'b0001;
	parameter Intra16x16ACLevel_s	= 4'b0011;
	parameter Intra16x16ACLevel_0_s = 4'b0010;
	parameter LumaLevel_s			= 4'b0110;
	parameter LumaLevel_0_s		    = 4'b0111;
	parameter ChromaDCLevel_Cb_s    = 4'b0101;
	parameter ChromaDCLevel_Cr_s	= 4'b0100;
	parameter ChromaACLevel_Cb_s	= 4'b1100;
	parameter ChromaACLevel_Cr_s	= 4'b1101;
	
	parameter Intra4x4_Vertical 			= 4'b0000;
	parameter Intra4x4_Horizontal 			= 4'b0001;
	parameter Intra4x4_DC 					= 4'b0010;
	parameter Intra4x4_Diagonal_Down_Left 	= 4'b0011;
	parameter Intra4x4_Diagonal_Down_Right 	= 4'b0100;
	parameter Intra4x4_Vertical_Right 		= 4'b0101;
	parameter Intra4x4_Horizontal_Down 		= 4'b0110;
	parameter Intra4x4_Vertical_Left 		= 4'b0111;
	parameter Intra4x4_Horizontal_Up 		= 4'b1000;
	
	parameter Intra16x16_Plane 			= 2'b11;
	parameter Intra_chroma_Plane		= 2'b11;
	
	parameter NumCoeffTrailingOnes_LUT = 4'b0010;
	//-------------------------------------------------
	//IQIT
	//-------------------------------------------------
	//gclk_end_of_one_residual_block
	//reg l_end_of_one_residual_block;
	//wire gclk_end_of_one_residual_block;
	//always @ (clk or end_of_one_residual_block)
	//	if (!clk) l_end_of_one_residual_block <= end_of_one_residual_block;
	//assign gclk_end_of_one_residual_block = clk & l_end_of_one_residual_block;
	
	//gclk_endof1NonZeroCoeffResBlk
	//reg l_end_of_NonZeroCoeff_CAVLC;
	//wire gclk_endof1NonZeroCoeffResBlk;
	//always @ (clk or end_of_NonZeroCoeff_CAVLC)
	//	if (!clk) l_end_of_NonZeroCoeff_CAVLC <= end_of_NonZeroCoeff_CAVLC;
	//assign gclk_endof1NonZeroCoeffResBlk = clk & l_end_of_NonZeroCoeff_CAVLC;
	
	//gclk_1D
	wire OneD_en;
	reg l_OneD_en;
	wire gclk_1D;
	assign OneD_en = (
	//	trap DC case after CAVLC:residual_state is still available now 
	(end_of_NonZeroCoeff_CAVLC == 1'b1 && cavlc_decoder_state != `NumCoeffTrailingOnes_LUT &&
	(residual_state == `Intra16x16DCLevel_s || residual_state == `ChromaDCLevel_Cb_s || 
	residual_state == `ChromaDCLevel_Cr_s)) ||  
    //	trap AC case after rescale:residual_state is still available now
	((residual_state == `Intra16x16ACLevel_s || residual_state == `LumaLevel_s || residual_state == `ChromaACLevel_Cb_s ||
	residual_state == `ChromaACLevel_Cr_s) && rescale_counter == 3'b100)	||
	//	trap internal loop
	OneD_counter != 0);
	always @ (clk or OneD_en)
		if (!clk) l_OneD_en <= OneD_en;
	assign gclk_1D = clk & l_OneD_en; 
	
	//gclk_2D
	wire TwoD_en;
	reg l_TwoD_en;
	wire gclk_2D;
	assign TwoD_en = ((OneD_counter == 3'b001 && residual_state != `ChromaDCLevel_Cb_s && residual_state != `ChromaDCLevel_Cr_s) 
					|| TwoD_counter != 0);
	always @ (clk or TwoD_en)
		if (!clk) l_TwoD_en <= TwoD_en;
	assign gclk_2D = clk & l_TwoD_en;
	
	//gclk_rescale
	wire rescale_en;
	reg l_rescale_en;
	wire gclk_rescale;
	assign rescale_en = (
	//trap AC after CAVLC except all zero coeffs case
   	(end_of_NonZeroCoeff_CAVLC == 1'b1 && cavlc_decoder_state != `NumCoeffTrailingOnes_LUT && (
   	residual_state == `Intra16x16ACLevel_s || residual_state == `LumaLevel_s || 
   	residual_state == `ChromaACLevel_Cb_s  || residual_state == `ChromaACLevel_Cr_s)) || 
   	//trap DC case after IDCT,chromaDC:after 1D-IDCT,lumaDC:after 2D-IDCT
	((residual_state == `Intra16x16DCLevel_s && TwoD_counter == 3'b100) ||
	((residual_state == `ChromaDCLevel_Cb_s || residual_state == `ChromaDCLevel_Cr_s) && OneD_counter == 3'b001)) ||
	//trap internal loop
	rescale_counter != 0);
	always @ (clk or rescale_en)
		if (!clk) l_rescale_en <= rescale_en;
	and gc_rescale (gclk_rescale,clk,l_rescale_en);
	
	//gclk_rounding
	wire rounding_en;
	reg l_rounding_en;
	wire gclk_rounding;
	assign rounding_en = (((residual_state == `Intra16x16ACLevel_s || residual_state == `LumaLevel_s ||
	residual_state == `ChromaACLevel_Cb_s || residual_state == `ChromaACLevel_Cr_s) && TwoD_counter == 3'b100)
	|| rounding_counter !=0)?1'b1:1'b0;
	always @ (clk or rounding_en)
		if (!clk) l_rounding_en <= rounding_en;
	assign gclk_rounding = clk & l_rounding_en;
	//-------------------------------------------------
	//Intra pred
	//-------------------------------------------------
	//1.gclk_intra_mbAddrA_luma @ Intra_pred_reg_ctrl.v
	//  For intra pred,update after every blk4x4 is summed
	//  For inter pred,update after blk4x4 5,7,13,15 is summed
	wire intra_mbAddrA_luma_ena;
	reg l_intra_mbAddrA_luma_ena;
	wire gclk_intra_mbAddrA_luma;
	wire Is_LumaRightMostBlk4x4;
	
	assign Is_LumaRightMostBlk4x4 = (blk4x4_rec_counter == 5 || blk4x4_rec_counter == 7 || 
									blk4x4_rec_counter == 13 || blk4x4_rec_counter == 15);