SOFA/BENCHMARK/cavlc_top/rtl/cavlc_len_gen.v

85 lines
3.9 KiB
Verilog

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