main.c

STR71X系列ARM微控制器原理与实践配套光盘

/******************** (C) COPYRIGHT 2003 ST Microelectronics *******************
*
* 文件说明：
*	CAN自循环模式
*
*******************************************************************************/

#include "71x_lib.h"

#include "main.h"
#include "LED.h"

#define RX_SIDE 0	// if RX_SIDE==1 ,the program acts as transmitter ,or acts as Receiver
   
canmsg RxCanMsg;
canmsg TxCanMsg[2] = {
	{ CAN_STD_ID,      0x0ff, 4, { 0x22, 0x33, 0x44, 0x00,0x55 } },
	{ CAN_EXT_ID, 0x12345678, 8, { 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17 } }
};

/*****************************************************************************/

void wait(void)
{
	u32 i;
	for(i = 0; i < 0xFFFFF; i++);
}

/*****************************************************************************/

void Main(void)
{
	#ifdef DEBUG
		debug();
	#endif

	LED_Init();

	// initialize the I/O ports for the CAN pins
	// setup GPIO 1.11 (CAN RX pin) as input Tristate CMOS
	GPIO_Config(GPIO1, 0x0800, GPIO_IN_TRI_CMOS);

	// setup GPIO 1.12 (CAN TX pin) as output alternate Push-pull
	GPIO_Config(GPIO1, 0x1000, GPIO_AF_PP);

	// initialize the CAN at a standard bitrate, interrupts disabled
	CAN_Init(0, CAN_BITRATE_125K);

	// switch into Loopback+Silent mode (self-test)
	CAN_EnterTestMode(CAN_TESTR_LBACK | CAN_TESTR_SILENT);

	// configure the message objects
	CAN_InvalidateAllMsgObj();
	CAN_SetTxMsgObj(CAN_TX_MSGOBJ, CAN_STD_ID);
	CAN_SetRxMsgObj(CAN_RX_MSGOBJ, CAN_STD_ID, 0, CAN_LAST_STD_ID, TRUE);

	while(1)
	{
		LED_Set(0, LED_OFF);
		wait();
		// send a pre-defined data frame
		CAN_SendMessage(CAN_TX_MSGOBJ, &TxCanMsg[0]);

		// wait until end of transmission
		CAN_WaitEndOfTx();

		// wait for reception of a data frame
		while (!CAN_ReceiveMessage(CAN_RX_MSGOBJ, FALSE, &RxCanMsg))
		{
			// add a time-out handling here, if necessary
		}

		LED_Set(0, LED_ON);
		wait();

		// release the message objects
		CAN_ReleaseTxMessage(CAN_TX_MSGOBJ);
		CAN_ReleaseRxMessage(CAN_RX_MSGOBJ);
	}
	// switch back into Normal mode
	CAN_LeaveTestMode();
}