unit dsPIC_CAN_RawBuffers;

// ******************************************************************************
//
// * Copyright:
//     (c) Mustangpeak Software 2012.
//
//     The contents of this file are subject to the GNU GPL v3 licence/ you maynot use
//     this file except in compliance with the License. You may obtain a copy of the
//     License at http://www.gnu.org/licenses/gpl.html
//
// * Revision History:
//     2012-04-01:   1.0.0.0 Created
//     2012-10-07:   Version 1.0
//
// * Description:
//    Implements a FIFO data structure for CAN Message Buffers
//
// ******************************************************************************

{$I Options.inc}

const

  CAN_DIRECTION_READ = 1;
  CAN_DIRECTION_WRITE = 0;
  
  MAX_ECAN_RX_BUFFER = 2;
  MAX_ECAN_TX_BUFFER = 2;
  
type
  // ***************************************************************************
  // CAN Message Buffers in raw form that can be loaded into the CAN controller
  // registers
  //   NOTE: For the dsPIC33 RX and TX are identical, for the dsPIC30 the bit
  //         patterns are different between RX and TX
  // ***************************************************************************
  TCANRawBuffer = record
    Word0    : Word;   // if Standard Message then SID else EID upper Bits
    Word1    : Word;   // if Standard Message then Data Length Code else low bits of EID and upper bits of SID
    Word2    : Word;   // if Standard Message then Data 0 and Data 1 else low bits of SID and Data Length Code
    Word3    : Word;   // if Standard Message then Data 2 and Data 3 else Data 0 and Data 1
    Word4    : Word;   // if Standard Message then Data 4 and Data 5 else Data 2 and Data 3
    Word5    : Word;   // if Standard Message then Data 6 and Data 7 else Data 4 and Data 5
    Word6    : Word;   // if Standard Message then, not used, else Data 6 and Data 7
    Word7    : Word;   // dsPIC33 only, For TX not used for RX the Filter that passed the message
  end;
  PCANRawBuffer = ^TCANRawBuffer;
  
const
  {$IFDEF P33FJ256GP710A}
  CAN_DMA_DATA_OFFSET = $7800;
  {$ELSE}
  CAN_DMA_DATA_OFFSET = $1000;                  // This is the start of the X-Data area.  Some of the dsPIC33s require DMA RAM to be
 {$ENDIF}                                       // located in this lower area.  Look at your chips datasheet to make sure this is acceptable

type
  TCAN_RxRawBufferArray = array[0..MAX_ECAN_RX_BUFFER-1] of TCANRawBuffer;
  TCAN_TxRawBufferArray = array[0..MAX_ECAN_TX_BUFFER-1] of TCANRawBuffer;
 

{$IFDEF P33EP512MU810}
var
  TX_Main_RawBufferArray: TCAN_TxRawBufferArray; far; dma;  // Transmit buffer for all filters.  The software pulls the data to the right list
  RX_Main_RawBufferArray: TCAN_RxRawBufferArray; far; dma;  // Recieve buffer for all filters.  The software moves the data to the right list
{$ELSE}
var
  TX_Main_RawBufferArray: TCAN_TxRawBufferArray; absolute CAN_DMA_DATA_OFFSET;                                                 // Transmit buffer for all filters.  The software pulls the data to the right list
  RX_Main_RawBufferArray: TCAN_RxRawBufferArray; absolute (CAN_DMA_DATA_OFFSET + (SizeOf(TCANRawBuffer)*MAX_ECAN_TX_BUFFER));  // Recieve buffer for all filters.  The software moves the data to the right list
{$ENDIF}

var
  Dummy: Word;

implementation

end.