b_canx1.c

This ZIP file contains the support files for programming the Infineon C167CR CAN interface. Refer to

/******************************************************************************
C167CR CAN Ap. Note project
Main - b_canx1

This is an example program showing how to use the CAN interface on the Keil
MCB167 evaluation board.

Copyright (c) 1997 Keil Software
******************************************************************************/
#include <stdio.h>
#include <intrins.h>
#include "can_ifc.h"
#include "can_msgs.h"

#define TIME_MO 1 /* message object number for time message */


/******************************************************************************
Setup CAN controller

Returns: nothing
-----------------------------------------------------------------------------*/
void
setup_can(void)
{
   begin_can_init();

   /* These mask values tell the CAN controller that all bits in a
      message id. are significant when comparing the id of a received message
      to the id's in the arbitration registers of the message objects.
   */
   CAN_MASK_SHORT = 0xffff;
   CAN_UMASK_LONG = 0xffff;
   CAN_LMASK_LONG = 0xf8ff;

   /* Since this program doesn't use message object 15, it is unnecessary
      to initialize the 'mask of last message' registers (CAN_UMASK_LAST and
      CAN_LMASK_LAST).
   */

   CAN_MSGOBJ[TIME_MO].msg_ctl = MSGVAL_CLR;
   CAN_MSGOBJ[TIME_MO].arbitr = ARBITR(CAN_TIME_MSG);
   CAN_MSGOBJ[TIME_MO].msg_cfg = MSG_CFG(LEN_CAN_TIME_MSG, CANDIR_RECEIVE, 0);
   CAN_MSGOBJ[TIME_MO].msg_ctl =
      /* clear bits     set bits */
         INTPND_CLR &
         RXIE_CLR &
         TXIE_CLR &
                        MSGVAL_SET &
         NEWDAT_CLR &
         MSGLST_CLR &
         TXRQ_CLR &
         RMTPND_CLR;

   /* CAN_IE_ must be set for any CAN interrupts to occur.
      CAN_EIE_ must be set for CAN error status change interrupts to occur.
   */
   end_can_init(CAN_IE_ | CAN_EIE_);
}


/******************************************************************************
main

What this program does:
   Setup the CAN interface, with a message object for receiving time message.
   Loop forever {
      Transmit time message remote frame.
      Wait for time message to be received.
      Process time message.
   }

Returns: never
-----------------------------------------------------------------------------*/
void
main(void)
{
   unsigned long time_value;
   unsigned long last_printed_time_value = 0ul - 1000ul;

   printf ("Program B start\n");

   /* Set up CAN interface */
   setup_can();

   /* Main loop */
   while (1) {
      /* Request time message.
         We're going to detect receipt of the message by examining NEWDAT
         (there are other ways), so also clear NEWDAT to make sure we process
         a new time message, not an old one that has been waiting around
         unprocessed.
      */
      CAN_MSGOBJ[TIME_MO].msg_ctl = TXRQ_SET & NEWDAT_CLR;

      /* Wait for updated time message
         Note: Doing it this way, the program will hang here forever if the
         message is not received.
      */
      while (!(CAN_MSGOBJ[TIME_MO].msg_ctl & NEWDAT_))  ;


      /* Process the time message */

      copy_received_can_message(TIME_MO, &time_value);
      /* If this time message is at least one second later than the last one
         that was output then output it.
      */
      if (time_value - last_printed_time_value >= 1000) {
         printf("%lu\n", time_value);
         last_printed_time_value = time_value;
      }
   }
}