Subversion Repositories nova

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

// Design    : nova

// Author(s) : Ke Xu

// Email           : eexuke@yahoo.com

// File      : end_of_blk_decoding.v

// Generated : June 12, 2005

// Copyright (C) 2008 Ke Xu                

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

// Description 

// Decoding end_of_one_residual_block signal for 1 cycle duration

// 1)for BitStream_parser_FSM to update signals such as i4x4 and direct state switch

// 2)for nC_decoding to update LumaLevel/ChromaLevel CurrMb,mbAddrA,mbAddrB

// Decoding end_of_residual signal for 1 cycle duration

// 1)for nC_decoding to update general control regs such as Luma_8x8_AllZeroCoeff_mbAddrA,Luma_8x8_AllZeroCoeff_mbAddrB_reg,Chroma_8x8_AllZeroCoeff_mbAddrA,Chroma_8x8_AllZeroCoeff_mbAddrB_reg

// 2)Note:for P_skip MBs,their general control regs as *8x8_ALLZeroCoeff* are directly controlled by the state instead of end_of_residual signal

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

// Revise log

// 1. March 24,2006

// Add signal end_of_NonZeroCoeff_CAVLC for IQIT to update res_AC/res_DC/... signals.

// end_of_NonZeroCoeff_CAVLC:combinational logic,active one cycle at the end of CAVLC decoding of one non zero coefficient residual.

// 2. March 29,2006

// Add signal lumaDC_IsAllZero,ChromaDC_Cb_IsAllZero,ChromaDC_Cr_IsAllZero to deal with special case:zero DC coeff,but non-zero AC coeff

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

// synopsys translate_off

`include "timescale.v"

// synopsys translate_on

`include "nova_defines.v"

module end_of_blk_decoding (reset_n,cavlc_decoder_state,

        TotalCoeff,i_TotalCoeff,end_of_one_residual_block,end_of_NonZeroCoeff_CAVLC

        );

        input reset_n;

        input [3:0] cavlc_decoder_state;

        input [4:0] TotalCoeff;

        input [3:0] i_TotalCoeff;

        output end_of_one_residual_block;

        output end_of_NonZeroCoeff_CAVLC;

        reg end_of_one_residual_block;

        reg end_of_NonZeroCoeff_CAVLC;

        reg lumaDC_IsAllZero;

        reg ChromaDC_Cb_IsAllZero;

        reg ChromaDC_Cr_IsAllZero;

        always @ (reset_n or cavlc_decoder_state or TotalCoeff or i_TotalCoeff)

                if (reset_n == 0)

                        end_of_one_residual_block <= 0;

                else if (cavlc_decoder_state == `NumCoeffTrailingOnes_LUT && TotalCoeff == 0)

                        end_of_one_residual_block <= 1;

                else if (cavlc_decoder_state == `LevelRunCombination && i_TotalCoeff == 0)

                        end_of_one_residual_block <= 1;

                else

                        end_of_one_residual_block <= 0;

        always @ (reset_n or cavlc_decoder_state or i_TotalCoeff)

                if (reset_n == 0)

                        end_of_NonZeroCoeff_CAVLC <= 0;

                else if (cavlc_decoder_state == `LevelRunCombination && i_TotalCoeff == 0)

                        end_of_NonZeroCoeff_CAVLC <= 1;

                else

                        end_of_NonZeroCoeff_CAVLC <= 0;

endmodule