bitstream_parser_fsm_gating.v

a H.264/AVC Baseline Decoder

//--------------------------------------------------------------------------------------------------
// Design    : nova
// Author(s) : Ke Xu
// Email	   : [e-mail]
// File      : BitStream_parser_FSM_gating.v
// Generated : June 26,2005
// Copyright (C) 2008 Ke Xu                
//-------------------------------------------------------------------------------------------------
// Description 
// BitStream_parser_FSM,clock gating version
//-------------------------------------------------------------------------------------------------

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

module BitStream_parser_FSM (clk,reset_n,end_of_one_blk4x4_sum,end_of_MB_DEC,
	gclk_parser,gclk_nal,gclk_slice,gclk_sps,gclk_pps,gclk_slice_header,
	gclk_slice_data,gclk_residual,gclk_cavlc,
	trigger_CAVLC,BitStream_buffer_valid_n,nal_unit_type,
	slice_type,num_ref_idx_active_override_flag,
	deblocking_filter_control_present_flag,disable_deblocking_filter_idc,
	mb_skip_run,mb_type_general,prev_intra4x4_pred_mode_flag,CodedBlockPatternLuma,
	CodedBlockPatternChroma,pc_2to0,NumSubMbPart,NumMbPart,
	TotalCoeff,TrailingOnes,maxNumCoeff,zerosLeft,run,
	
	parser_state,nal_unit_state,slice_layer_wo_partitioning_state,slice_header_state,slice_header_s6,
	ref_pic_list_reordering_state,dec_ref_pic_marking_state,slice_data_state,sub_mb_pred_state,
	mb_pred_state,seq_parameter_set_state,pic_parameter_set_state,residual_state,cavlc_decoder_state,
	heading_one_en,pic_num,mb_num,mb_num_h,mb_num_v,
	NextMB_IsSkip,LowerMB_IsSkip,Is_skip_run_entry,Is_skip_run_end,
	luma4x4BlkIdx,mbPartIdx,subMbPartIdx,compIdx,i8x8,i4x4,i4x4_CbCr,
	coeffNum,i_level,i_run,i_TotalCoeff,
	suffix_length_initialized,IsRunLoop);
	input clk;
	input reset_n;
	input end_of_one_blk4x4_sum;
	input end_of_MB_DEC;
	input gclk_parser;
	input gclk_nal;
	input gclk_slice;
	input gclk_sps;
	input gclk_pps;
	input gclk_slice_header;
	input gclk_slice_data;
	input gclk_residual;
	input gclk_cavlc;
	input trigger_CAVLC;
	input BitStream_buffer_valid_n;
	input [4:0] nal_unit_type;
	input [2:0] slice_type;
	input num_ref_idx_active_override_flag;
	input deblocking_filter_control_present_flag;
	input [1:0] disable_deblocking_filter_idc;
	input [6:0] mb_skip_run;
	input [3:0] mb_type_general;
	input prev_intra4x4_pred_mode_flag;
	input [3:0] CodedBlockPatternLuma;
	input [1:0] CodedBlockPatternChroma;
	input [2:0] pc_2to0;
	input [2:0] NumMbPart;
	input [2:0] NumSubMbPart;
	input [4:0] TotalCoeff;
	input [1:0] TrailingOnes;
	input [4:0] maxNumCoeff;
	input [3:0] zerosLeft;
	input [3:0] run;
	
	output [1:0] parser_state;
	output [2:0] nal_unit_state;
	output [1:0] slice_layer_wo_partitioning_state;
	output [3:0] slice_header_state; 
	output slice_header_s6;
	output [2:0] ref_pic_list_reordering_state;
	output [1:0] dec_ref_pic_marking_state;
	output [3:0] slice_data_state;
	output [1:0] sub_mb_pred_state;
	output [2:0] mb_pred_state;
	output [3:0] seq_parameter_set_state;
	output [3:0] pic_parameter_set_state;
	output [3:0] residual_state;
	output [3:0] cavlc_decoder_state;
	output heading_one_en;
	output [5:0] pic_num;
	output [6:0] mb_num;
	output [3:0] mb_num_h;
	output [3:0] mb_num_v;
	output NextMB_IsSkip;
	output LowerMB_IsSkip;
	output Is_skip_run_entry;
	output Is_skip_run_end;
	output [3:0] luma4x4BlkIdx;
	output [1:0] mbPartIdx;
	output [1:0] subMbPartIdx;
	output compIdx;
	output [1:0] i8x8,i4x4;
	output [1:0] i4x4_CbCr;
	output [3:0] coeffNum;
	output [3:0] i_level;
	output [3:0] i_run;
	output [3:0] i_TotalCoeff;
	output suffix_length_initialized;
	output IsRunLoop;
	
	reg [1:0] parser_state;
	reg [2:0] nal_unit_state;
	reg [1:0] slice_layer_wo_partitioning_state;
	reg [3:0] seq_parameter_set_state;
	reg [3:0] pic_parameter_set_state;
	reg [3:0] slice_header_state;
	reg [2:0] ref_pic_list_reordering_state;
 	reg [1:0] dec_ref_pic_marking_state;
	reg [3:0] slice_data_state;
	reg [2:0] mb_pred_state;
	reg [1:0] sub_mb_pred_state;
	reg [3:0] residual_state;
	reg [3:0] cavlc_decoder_state;
	
	wire heading_one_en;
	reg [6:0] mb_num;
	reg [3:0] mb_num_h;
	reg [3:0] mb_num_v;
	reg [1:0] mbPartIdx;
	reg [1:0] subMbPartIdx;
	reg compIdx;
	reg	[1:0] i8x8,i4x4;
	reg [1:0] i4x4_CbCr;
	reg [3:0] coeffNum;
	reg [3:0] coeffNum_reg;
	reg [3:0] i_level,i_run,i_TotalCoeff;
	reg [6:0] count_mb_skip_run;//number of MBs to be skipped
	reg [7:0] count_pcm_byte;
	reg [3:0] luma4x4BlkIdx;
	reg [5:0] pic_num;
	reg suffix_length_initialized;
	reg IsRunLoop;
	
	/*
	// synopsys translate_off
	integer	tracefile;
	initial
		begin
			tracefile = $fopen("trace.txt");
		end
	// synopsys translate_on
	*/

	//--------------
	//parser_state
	//--------------
	always @ (posedge gclk_parser or negedge reset_n)
		if (reset_n == 0)
			parser_state <= `rst_parser;
		else
			case (parser_state)
				`rst_parser			  :parser_state <= (BitStream_buffer_valid_n == 1'b0)? `start_code_prefix:`rst_parser;
				`start_code_prefix:parser_state <= `nal_unit;
				`nal_unit			    :parser_state <= `rst_parser;
			endcase
	//---------------
	//nal_unit_state
	//---------------
	always @ (posedge gclk_nal or negedge reset_n)
		if (reset_n == 0)
			nal_unit_state <= `rst_nal_unit;
		else
			case (nal_unit_state)
				`rst_nal_unit:nal_unit_state <= `forbidden_zero_bit_2_nal_unit_type;
				`forbidden_zero_bit_2_nal_unit_type:
				case (nal_unit_type)
					5'b00001:nal_unit_state <= `slice_layer_non_IDR_rbsp;
					5'b00101:nal_unit_state <= `slice_layer_IDR_rbsp;
					5'b00111:nal_unit_state <= `seq_parameter_set_rbsp;
					5'b01000:nal_unit_state <= `pic_parameter_set_rbsp;
				endcase
				`slice_layer_non_IDR_rbsp,`slice_layer_IDR_rbsp:nal_unit_state <= `rbsp_trailing_one_bit;
				`seq_parameter_set_rbsp :nal_unit_state <= `rbsp_trailing_one_bit;
				`pic_parameter_set_rbsp :nal_unit_state <= `rbsp_trailing_one_bit; 
				`rbsp_trailing_one_bit  :nal_unit_state <= (pc_2to0 == 3'b000)? `rst_nal_unit:`rbsp_trailing_zero_bits;
				`rbsp_trailing_zero_bits:nal_unit_state <= `rst_nal_unit;
			endcase
	//----------------------------------
	//slice_layer_wo_partitioning_state
	//----------------------------------
	always @ (posedge gclk_slice or negedge reset_n)
		if (reset_n == 1'b0)
			slice_layer_wo_partitioning_state <= `rst_slice_layer_wo_partitioning;
		else
			case (slice_layer_wo_partitioning_state)
				`rst_slice_layer_wo_partitioning	:slice_layer_wo_partitioning_state <= `slice_header;
				`slice_header					            :slice_layer_wo_partitioning_state <= `slice_data;
				`slice_data						            :slice_layer_wo_partitioning_state <= `rst_slice_layer_wo_partitioning;
			endcase
	//------------------------
	//seq_parameter_set_state
	//------------------------
	always @ (posedge gclk_sps or negedge reset_n)
		if (reset_n == 0)
			seq_parameter_set_state <= `rst_seq_parameter_set;
		else
			case (seq_parameter_set_state)
				`rst_seq_parameter_set					          :seq_parameter_set_state <= `fixed_header;
				`fixed_header							                :seq_parameter_set_state <= `level_idc_s;
				`level_idc_s								              :seq_parameter_set_state <= `seq_parameter_set_id_sps_s;
				`seq_parameter_set_id_sps_s				        :seq_parameter_set_state <= `log2_max_frame_num_minus4_s;
				`log2_max_frame_num_minus4_s				      :seq_parameter_set_state <= `pic_order_cnt_type_s;
				`pic_order_cnt_type_s					            :seq_parameter_set_state <= `log2_max_pic_order_cnt_lsb_minus4_s;
				`log2_max_pic_order_cnt_lsb_minus4_s		  :seq_parameter_set_state <= `num_ref_frames_s;
				`num_ref_frames_s						              :seq_parameter_set_state <= `gaps_in_frame_num_value_allowed_flag_s;
				`gaps_in_frame_num_value_allowed_flag_s	  :seq_parameter_set_state <= `pic_width_in_mbs_minus1_s;
				`pic_width_in_mbs_minus1_s				        :seq_parameter_set_state <= `pic_height_in_map_units_minus1_s;
				`pic_height_in_map_units_minus1_s		      :seq_parameter_set_state <= `frame_mbs_only_flag_2_frame_cropping_flag;
				`frame_mbs_only_flag_2_frame_cropping_flag:seq_parameter_set_state <= `vui_parameter_present_flag_s;
				`vui_parameter_present_flag_s			        :seq_parameter_set_state <= `rst_seq_parameter_set;
			endcase
	//------------------------
	//pic_parameter_set_state
	//------------------------
	always @ (posedge gclk_pps or negedge reset_n)
		if (reset_n == 0)
			pic_parameter_set_state <= `rst_pic_parameter_set;
		else
			case (pic_parameter_set_state)
				`rst_pic_parameter_set				                             :pic_parameter_set_state <= `pic_parameter_set_id_pps_s;
				`pic_parameter_set_id_pps_s			                           :pic_parameter_set_state <= `seq_parameter_set_id_pps_s;
				`seq_parameter_set_id_pps_s			                           :pic_parameter_set_state <= `entropy_coding_mode_flag_2_pic_order_present_flag;
				`entropy_coding_mode_flag_2_pic_order_present_flag         :pic_parameter_set_state <= `num_slice_groups_minus1_s;
				`num_slice_groups_minus1_s			                           :pic_parameter_set_state <= `num_ref_idx_l0_active_minus1_pps_s;
				`num_ref_idx_l0_active_minus1_pps_s	                       :pic_parameter_set_state <= `num_ref_idx_l1_active_minus1_pps_s;
				`num_ref_idx_l1_active_minus1_pps_s	                       :pic_parameter_set_state <= `weighted_pred_flag_2_weighted_bipred_idc;
				`weighted_pred_flag_2_weighted_bipred_idc                  :pic_parameter_set_state <= `pic_init_qp_minus26_s;
				`pic_init_qp_minus26_s				                             :pic_parameter_set_state <= `pic_init_qs_minus26_s;
				`pic_init_qs_minus26_s				                             :pic_parameter_set_state <= `chroma_qp_index_offset_s;
				`chroma_qp_index_offset_s			                             :pic_parameter_set_state <= `deblocking_filter_control_2_redundant_pic_cnt_present_flag;
				`deblocking_filter_control_2_redundant_pic_cnt_present_flag:pic_parameter_set_state <= `rst_pic_parameter_set;
			endcase
	//-------------------
	//slice_header_state
	//-------------------
	always @ (posedge gclk_slice_header or negedge reset_n)
		if (reset_n == 0)
			begin
				slice_header_state            <= `rst_slice_header;
				ref_pic_list_reordering_state <= `rst_ref_pic_list_reordering;
				dec_ref_pic_marking_state     <= `rst_dec_ref_pic_marking;
			end
		else
			case (slice_header_state)
				`rst_slice_header                   :slice_header_state <= `first_mb_in_slice_s;
				`first_mb_in_slice_s                :slice_header_state <= `slice_type_s;
				`slice_type_s                       :slice_header_state <= `pic_parameter_set_id_slice_header_s;
				`pic_parameter_set_id_slice_header_s:slice_header_state <= `frame_num_s;
				`frame_num_s:
				if (nal_unit_type == 5'b00101)	     slice_header_state <= `idr_pic_id_s;
				else							                   slice_header_state <= `pic_order_cnt_lsb_s;
				`idr_pic_id_s                       :slice_header_state <= `pic_order_cnt_lsb_s;
				`pic_order_cnt_lsb_s:
				if (slice_type == 3'b101) 	         slice_header_state <= `num_ref_idx_active_override_flag_s;
				else						                     slice_header_state <= `dec_ref_pic_marking;
				`num_ref_idx_active_override_flag_s:
				if (num_ref_idx_active_override_flag == 1'b1) slice_header_state <= `num_ref_idx_l0_active_minus1_slice_header_s;
				else                                          slice_header_state <= `ref_pic_list_reordering;
				`num_ref_idx_l0_active_minus1_slice_header_s :slice_header_state <= `ref_pic_list_reordering;
				`ref_pic_list_reordering:
				case (ref_pic_list_reordering_state)
					`rst_ref_pic_list_reordering:
					if (slice_type == 3'b101)
						ref_pic_list_reordering_state <= `ref_pic_list_reordering_flag_l0_s;
					else
						begin
							ref_pic_list_reordering_state <= `rst_ref_pic_list_reordering;
							slice_header_state            <= `dec_ref_pic_marking;
						end
					`ref_pic_list_reordering_flag_l0_s:
					begin
						ref_pic_list_reordering_state <= `rst_ref_pic_list_reordering;
						slice_header_state            <= `dec_ref_pic_marking;
					end
				endcase
				`dec_ref_pic_marking:
				case (dec_ref_pic_marking_state)
					`rst_dec_ref_pic_marking:
					dec_ref_pic_marking_state <= (nal_unit_type == 3'b101)? `no_output_of_prior_pics_flag_2_long_term_reference_flag:`adaptive_ref_pic_marking_mode_flag_s;
					`no_output_of_prior_pics_flag_2_long_term_reference_flag:
					begin
						dec_ref_pic_marking_state <= `rst_dec_ref_pic_marking;
						slice_header_state        <= `slice_qp_delta_s;
					end
					`adaptive_ref_pic_marking_mode_flag_s:
					begin
						dec_ref_pic_marking_state <= `rst_dec_ref_pic_marking;
						slice_header_state        <= `slice_qp_delta_s;
					end
				endcase
				`slice_qp_delta_s:
				slice_header_state <= (deblocking_filter_control_present_flag == 1'b1)? `disable_deblocking_filter_idc_s:`rst_slice_header;
				`disable_deblocking_filter_idc_s:
				slice_header_state <= (disable_deblocking_filter_idc != 2'b01)? `slice_alpha_c0_offset_div2_s:`rst_slice_header;
				`slice_alpha_c0_offset_div2_s:slice_header_state <= `slice_beta_offset_div2_s;
				`slice_beta_offset_div2_s	   :slice_header_state <= `rst_slice_header;
			endcase
	
	assign slice_header_s6 = (slice_header_state == `frame_num_s)? 1'b1:1'b0;
	//------------------
	//slice_data_state
	//------------------
	reg  Is_skip_run_entry;	//for trigger inter pred.Originally it's a wire type which will trigger inter_pred signal too early
							            //than expected:cause inter_pred rise up before mv_below8x8 is set to 4'b0 for P_skip.Thus the 
							            //preload_counter after inter_pred will sample wrong mv_below8x8/mv_below8x8_curr.
							            //Then it is changed to reg type to appear one cycle later @ May 15,2006
	wire Is_skip_run_end;   //for stop triggering inter pred 
		
	always @ (posedge clk)
		if (reset_n == 1'b0)
			Is_skip_run_entry <= 1'b0;
		else if (slice_data_state == `mb_skip_run_s && mb_skip_run != 0)
			Is_skip_run_entry <= 1'b1;
		else 
			Is_skip_run_entry <= 1'b0;