ccan_rom.c

Go to the documentation of this file.

/*
 * @brief CCAN on-chip driver example
 *
 * @note
 * Copyright(C) NXP Semiconductors, 2012
 * All rights reserved.
 *
 * @par
 * Software that is described herein is for illustrative purposes only
 * which provides customers with programming information regarding the
 * LPC products.  This software is supplied "AS IS" without any warranties of
 * any kind, and NXP Semiconductors and its licensor disclaim any and
 * all warranties, express or implied, including all implied warranties of
 * merchantability, fitness for a particular purpose and non-infringement of
 * intellectual property rights.  NXP Semiconductors assumes no responsibility
 * or liability for the use of the software, conveys no license or rights under any
 * patent, copyright, mask work right, or any other intellectual property rights in
 * or to any products. NXP Semiconductors reserves the right to make changes
 * in the software without notification. NXP Semiconductors also makes no
 * representation or warranty that such application will be suitable for the
 * specified use without further testing or modification.
 *
 * @par
 * Permission to use, copy, modify, and distribute this software and its
 * documentation is hereby granted, under NXP Semiconductors' and its
 * licensor's relevant copyrights in the software, without fee, provided that it
 * is used in conjunction with NXP Semiconductors microcontrollers.  This
 * copyright, permission, and disclaimer notice must appear in all copies of
 * this code.
 */
#include "board.h"

/*****************************************************************************
 * Private types/enumerations/variables
 ****************************************************************************/

#define TEST_CCAN_BAUD_RATE 500000

CCAN_MSG_OBJ_T msg_obj;

/*****************************************************************************
 * Public types/enumerations/variables
 ****************************************************************************/

/*****************************************************************************
 * Private functions
 ****************************************************************************/
void baudrateCalculate(uint32_t baud_rate, uint32_t *can_api_timing_cfg)
{
 uint32_t pClk, div, quanta, segs, seg1, seg2, clk_per_bit, can_sjw;
 Chip_Clock_EnablePeriphClock(SYSCTL_CLOCK_CAN);
 pClk = Chip_Clock_GetMainClockRate();

 clk_per_bit = pClk / baud_rate;

 for (div = 0; div <= 15; div++) {
  for (quanta = 1; quanta <= 32; quanta++) {
   for (segs = 3; segs <= 17; segs++) {
    if (clk_per_bit == (segs * quanta * (div + 1))) {
     segs -= 3;
     seg1 = segs / 2;
     seg2 = segs - seg1;
     can_sjw = seg1 > 3 ? 3 : seg1;
     can_api_timing_cfg[0] = div;
     can_api_timing_cfg[1] =
      ((quanta - 1) & 0x3F) | (can_sjw & 0x03) << 6 | (seg1 & 0x0F) << 8 | (seg2 & 0x07) << 12;
     return;
    }
   }
  }
 }
}

/* CAN receive callback */
/* Function is executed by the Callback handler after
    a CAN message has been received */
void CAN_rx(uint8_t msg_obj_num) {
 /* Determine which CAN message has been received */
 msg_obj.msgobj = msg_obj_num;
 /* Now load up the msg_obj structure with the CAN message */
 LPC_CCAN_API->can_receive(&msg_obj);
 if (msg_obj_num == 1) {
  /* Simply transmit CAN frame (echo) with with ID +0x100 via buffer 2 */
  msg_obj.msgobj = 2;
  msg_obj.mode_id += 0x100;
  LPC_CCAN_API->can_transmit(&msg_obj);
 }
}

/* CAN transmit callback */
/* Function is executed by the Callback handler after
    a CAN message has been transmitted */
void CAN_tx(uint8_t msg_obj_num) {}

/* CAN error callback */
/* Function is executed by the Callback handler after
    an error has occured on the CAN bus */
void CAN_error(uint32_t error_info) {}

void CAN_IRQHandler(void) {
 LPC_CCAN_API->isr();
}

/*****************************************************************************
 * Public functions
 ****************************************************************************/

int main(void)
{
 uint32_t CanApiClkInitTable[2];
 /* Publish CAN Callback Functions */
 CCAN_CALLBACKS_T callbacks = {
  CAN_rx,
  CAN_tx,
  CAN_error,
  NULL,
  NULL,
  NULL,
  NULL,
  NULL,
 };
 Board_Init();
 baudrateCalculate(TEST_CCAN_BAUD_RATE, CanApiClkInitTable);

 LPC_CCAN_API->init_can(&CanApiClkInitTable[0], TRUE);
 /* Configure the CAN callback functions */
 LPC_CCAN_API->config_calb(&callbacks);
 /* Enable the CAN Interrupt */
 NVIC_EnableIRQ(CAN_IRQn);

 /* Send a simple one time CAN message */
 msg_obj.msgobj  = 0;
 msg_obj.mode_id = 0x345;
 msg_obj.mask    = 0x0;
 msg_obj.dlc     = 4;
 msg_obj.data[0] = 'T'; // 0x54
 msg_obj.data[1] = 'E'; // 0x45
 msg_obj.data[2] = 'S'; // 0x53
 msg_obj.data[3] = 'T'; // 0x54
 LPC_CCAN_API->can_transmit(&msg_obj);

 /* Configure message object 1 to receive all 11-bit messages 0x400-0x4FF */
 msg_obj.msgobj = 1;
 msg_obj.mode_id = 0x400;
 msg_obj.mask = 0x700;
 LPC_CCAN_API->config_rxmsgobj(&msg_obj);

 while (1) {
  __WFI(); /* Go to Sleep */
 }
}