Subversion Repositories cavlc

//////////////////////////////////////////////////////////////////////

////                                                              ////

////  cavlc_len_gen                                               ////

////                                                              ////

////  Description                                                 ////

////      generate the number of bits to forward                  ////

////                                                              ////

////  Author(s):                                                  ////

////      - bin qiu, qiubin@opencores.org                         ////

////                                                              ////

//////////////////////////////////////////////////////////////////////

////                                                              ////

//// Copyright (C) 2011 Authors and OPENCORES.ORG                 ////

////                                                              ////

//// This source file may be used and distributed without         ////

//// restriction provided that this copyright statement is not    ////

//// removed from the file and that any derivative work contains  ////

//// the original copyright notice and the associated disclaimer. ////

////                                                              ////

//// This source file is free software; you can redistribute it   ////

//// and/or modify it under the terms of the GNU Lesser General   ////

//// Public License as published by the Free Software Foundation; ////

//// either version 2.1 of the License, or (at your option) any   ////

//// later version.                                               ////

////                                                              ////

//// This source is distributed in the hope that it will be       ////

//// useful, but WITHOUT ANY WARRANTY; without even the implied   ////

//// warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR      ////

//// PURPOSE.  See the GNU Lesser General Public License for more ////

//// details.                                                     ////

////                                                              ////

//// You should have received a copy of the GNU Lesser General    ////

//// Public License along with this source; if not, download it   ////

//// from http://www.opencores.org/lgpl.shtml                     ////

////                                                              ////

//////////////////////////////////////////////////////////////////////

//2011-8-7 20:19    initial revision

`include "defines.v"

module cavlc_len_gen

(

    cavlc_state,

    len_read_total_coeffs_comb,

    len_read_levels_comb,

    len_read_total_zeros_comb,

    len_read_run_befores_comb,

    len_comb

);

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

// ports

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

input  [7:0] cavlc_state;

input  [4:0] len_read_total_coeffs_comb;

input  [4:0] len_read_levels_comb;

input  [3:0] len_read_total_zeros_comb;

input  [3:0] len_read_run_befores_comb;

output [4:0] len_comb;

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

// regs

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

reg [4:0] len_comb;         //number of bits comsumed by cavlc in a cycle

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

// len_comb

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

always @ (*)

case (1'b1) //synthesis parallel_case

    cavlc_state[`cavlc_read_total_coeffs_bit]  : len_comb <= len_read_total_coeffs_comb;

    cavlc_state[`cavlc_read_t1s_flags_bit],

    cavlc_state[`cavlc_read_level_prefix_bit],

    cavlc_state[`cavlc_read_level_suffix_bit]  : len_comb <= len_read_levels_comb;

    cavlc_state[`cavlc_read_total_zeros_bit]   : len_comb <= len_read_total_zeros_comb;

    cavlc_state[`cavlc_read_run_befores_bit]   : len_comb <= len_read_run_befores_comb;

    cavlc_state[`cavlc_calc_level_bit],

    cavlc_state[`cavlc_idle_bit]               : len_comb <= 0;

    default                                    : len_comb <= 'bx;

endcase

endmodule