can_acf.v

一个用硬件描述语言编写CAN总线控制器的IP

//////////////////////////////////////////////////////////////////////
////                                                              ////
////  can_acf.v                                                   ////
////                                                              ////
////                                                              ////
////  This file is part of the CAN Protocol Controller            ////
////  http://www.opencores.org/projects/can/                      ////
////                                                              ////
////                                                              ////
////  Author(s):                                                  ////
////       Igor Mohor                                             ////
////       [e-mail]                                    ////
////                                                              ////
////                                                              ////
////  All additional information is available in the README.txt   ////
////  file.                                                       ////
////                                                              ////
//////////////////////////////////////////////////////////////////////
////                                                              ////
//// Copyright (C) 2002, 2003, 2004 Authors                       ////
////                                                              ////
//// 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                     ////
////                                                              ////
//// The CAN protocol is developed by Robert Bosch GmbH and       ////
//// protected by patents. Anybody who wants to implement this    ////
//// CAN IP core on silicon has to obtain a CAN protocol license  ////
//// from Bosch.                                                  ////
////                                                              ////
//////////////////////////////////////////////////////////////////////
//
// CVS Revision History
//
// $Log: can_acf.v,v $
// Revision 1.9  2004/05/31 14:46:11  igorm
// Bit acceptance_filter_mode was inverted.
//
// Revision 1.8  2004/02/08 14:16:44  mohor
// Header changed.
//
// Revision 1.7  2003/07/16 13:41:34  mohor
// Fixed according to the linter.
//
// Revision 1.6  2003/02/10 16:02:11  mohor
// CAN is working according to the specification. WB interface and more
// registers (status, IRQ, ...) needs to be added.
//
// Revision 1.5  2003/02/09 18:40:29  mohor
// Overload fixed. Hard synchronization also enabled at the last bit of
// interframe.
//
// Revision 1.4  2003/02/09 02:24:33  mohor
// Bosch license warning added. Error counters finished. Overload frames
// still need to be fixed.
//
// Revision 1.3  2003/01/31 01:13:37  mohor
// backup.
//
// Revision 1.2  2003/01/14 12:19:35  mohor
// rx_fifo is now working.
//
// Revision 1.1  2003/01/08 02:13:15  mohor
// Acceptance filter added.
//
//
//
//

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

module can_acf
( 
  clk,
  rst,

  id,
  
  /* Mode register */
  reset_mode,
  acceptance_filter_mode,

  extended_mode,
  
  acceptance_code_0,
  acceptance_code_1,
  acceptance_code_2,
  acceptance_code_3,
  acceptance_mask_0,
  acceptance_mask_1,
  acceptance_mask_2,
  acceptance_mask_3,
  
  go_rx_crc_lim,
  go_rx_inter,
  go_error_frame,
  
  data0,
  data1,
  rtr1,
  rtr2,
  ide,
  no_byte0,
  no_byte1,

  
  id_ok
  
  
);

parameter Tp = 1;

input         clk;
input         rst;
input  [28:0] id;
input         reset_mode;
input         acceptance_filter_mode;
input         extended_mode;

input   [7:0] acceptance_code_0;
input   [7:0] acceptance_code_1;
input   [7:0] acceptance_code_2;
input   [7:0] acceptance_code_3;
input   [7:0] acceptance_mask_0;
input   [7:0] acceptance_mask_1;
input   [7:0] acceptance_mask_2;
input   [7:0] acceptance_mask_3;
input         go_rx_crc_lim;
input         go_rx_inter;
input         go_error_frame;
input   [7:0] data0;
input   [7:0] data1;
input         rtr1;
input         rtr2;
input         ide;
input         no_byte0;
input         no_byte1;


output        id_ok;

reg           id_ok;

wire          match;
wire          match_sf_std;
wire          match_sf_ext;
wire          match_df_std;
wire          match_df_ext;


// Working in basic mode. ID match for standard format (11-bit ID).
assign match =        ( (id[3]  == acceptance_code_0[0] | acceptance_mask_0[0] ) &
                        (id[4]  == acceptance_code_0[1] | acceptance_mask_0[1] ) &
                        (id[5]  == acceptance_code_0[2] | acceptance_mask_0[2] ) &
                        (id[6]  == acceptance_code_0[3] | acceptance_mask_0[3] ) &
                        (id[7]  == acceptance_code_0[4] | acceptance_mask_0[4] ) &
                        (id[8]  == acceptance_code_0[5] | acceptance_mask_0[5] ) &
                        (id[9]  == acceptance_code_0[6] | acceptance_mask_0[6] ) &
                        (id[10] == acceptance_code_0[7] | acceptance_mask_0[7] )
                      );


// Working in extended mode. ID match for standard format (11-bit ID). Using single filter.
assign match_sf_std = ( (id[3]  == acceptance_code_0[0] | acceptance_mask_0[0] ) &
                        (id[4]  == acceptance_code_0[1] | acceptance_mask_0[1] ) &
                        (id[5]  == acceptance_code_0[2] | acceptance_mask_0[2] ) &
                        (id[6]  == acceptance_code_0[3] | acceptance_mask_0[3] ) &
                        (id[7]  == acceptance_code_0[4] | acceptance_mask_0[4] ) &
                        (id[8]  == acceptance_code_0[5] | acceptance_mask_0[5] ) &
                        (id[9]  == acceptance_code_0[6] | acceptance_mask_0[6] ) &
                        (id[10] == acceptance_code_0[7] | acceptance_mask_0[7] ) &