ir.c

瑞萨(Renesas)M16C系列芯片的函数库

#include "ir.h"	// infrared utility header file
#include "timer.h"	// timer utility header file
#include "sfr62p.h"	// SFR definition of M16C/62P

#define	IFR_BAUD			16	// the times to control sending data

static char cSending 			= 0;	// flag for the character is sending
static char cSendBits 			= 0;	// bit count
static char CanRec 				= 0;	// flag for a character is received
static char cSendTimerCount		= 0;	// count of times of SendTimer() executed
static char cRevTimerCount		= 0;	// count of times of RecTimer() executed
static char cReving				= 0;	// flag for the character is receiving
static char cStartBit			= 0;	// flag for the start bit is received
static char cRevBits			= 0;	// count of bits received
static unsigned char ucRecBuf 	= 0;	// receive buffer
static unsigned char ucSendBuf 	= 0;	// send buffer

/*""FUNC COMMENT""*************************************************************
* ID         		: ---
* Function name     : void InitIR(void)
* Function     		: initialize infrared input and output
* Paramenter   		: none
* Return 	 		: none
* Function used		: InitTA0()	: Initialize TA0
*					: InitTA3()	: Initialize TA3
* Notice	   		: none
* History    		: ---
*""FUNC COMMENT END""*********************************************************/
void InitIR(void)
{
	pd7_6 = 1;	// set P7_6 (infrared output) as output
	p7_6 = 0;	// initialize P7_6
	pd9_0 = 0;	// set P9_0 (infrared input)as input
	InitTA0();	// initialize TA0
	InitTA3();	// initialize TA3
}

/*""FUNC COMMENT""*************************************************************
* ID         		: ---
* Function name     : void Busy(void)
* Function     		: to show the period of sending
* Paramenter   		: none
* Return 	 		: char : the flag for the character is sending
* Function used		: none
* Notice	   		: none
* History    		: ---
*""FUNC COMMENT END""*********************************************************/
char Busy(void)
{
	return cSending;	// return the flag for the character is sending
}

/*""FUNC COMMENT""*************************************************************
* ID         		: ---
* Function name     : void CanReceive(void)
* Function     		: to show if a character is received
* Paramenter   		: none
* Return 	 		: char : the flag for a character is received
* Function used		: none
* Notice	   		: none
* History    		: ---
*""FUNC COMMENT END""*********************************************************/
char CanReceive(void)
{
	return CanRec;	// return the flag for a character is received
}

/*""FUNC COMMENT""*************************************************************
* ID         		: ---
* Function name     : void CanReceive(void)
* Function     		: send a character
* Paramenter   		: unsigned char cSend : the character to be sent
* Return 	 		: char : process result
* Function used		: none
* Notice	   		: none
* History    		: ---
*""FUNC COMMENT END""*********************************************************/
char Send(unsigned char cSend)
{
	if(cSending)	// if there is a character sending, return
		return 0;

	asm("FCLR I");	// disable interrupt

	cSendTimerCount = 0;	// clear sending times
	ucSendBuf 	= cSend;	// set send buffer
	cSending 	= 1;		// set sending flag
	cSendBits 	= 0;		// clear bit sent

	asm("FSET I");	// enable interrupt

	return 1;
}

/*""FUNC COMMENT""*************************************************************
* ID         		: ---
* Function name     : void SendTimer(void)
* Function     		: when the function is executed 16 times, 1 bit is sent
* Paramenter   		: none
* Return 	 		: none
* Function used		: none
* Notice	   		: none
* History    		: ---
*""FUNC COMMENT END""*********************************************************/
void SendTimer(void)
{
	if(!cSending)	// if there is not character sending, return
		return;
				
	
	if(cSendBits == 0)	// send the start bit
	{
	    ta3s 	= 1;	// start TA3

		// if the function is executed 16 times, the bit is sent. Sending 1 bit need 1 / 1200 (s),
		// the function is executed every 1 / 19200 (s)
		if(cSendTimerCount >= IFR_BAUD)	
		{
			cSendTimerCount = 0;	// clear count of times of SendTimer() executed
			cSendBits ++;	// send the next bit
		}
	}
	else if(cSendBits == 9)	// send the stop bit
	{
		ta3s 	= 0;	// disable TA3

		if(cSendTimerCount >= IFR_BAUD*2)	// the stop bit is sent twice
		{
			cSendTimerCount = 0;	// clear count of times of SendTimer() executed
			cSendBits = 0;	// clear the bit count
			cSending = 0;	// clear the sending flag
		}
	}
	else	// send the data bit
	{
		if(cSendTimerCount == 1)	// the first time to send data bit
		{
			if((ucSendBuf >> (cSendBits-1)) & 0x01)	// check the data bit
			{
				ta3s 	= 0;	// if 1, not send
			}
			else
			{
				ta3s 	= 1;	// if 0, send
			}
		}

		if(cSendTimerCount >= IFR_BAUD)	// a bit is sent
		{
			cSendTimerCount = 0;	// clear count of times of SendTimer() executed
			cSendBits ++;	// clear bit count
		}
	}

	cSendTimerCount ++;	// increase count of times of SendTimer() executed

}

/*""FUNC COMMENT""*************************************************************
* ID         		: ---
* Function name     : void Receive(void)
* Function     		: receive a character
* Paramenter   		: none
* Return 	 		: unsigned char : the data received
* Function used		: none
* Notice	   		: none
* History    		: ---
*""FUNC COMMENT END""*********************************************************/
unsigned char Receive(void)
{
	CanRec = 0;	// clear the flag for a character is received
	return ucRecBuf;	// return the character received
}

/*""FUNC COMMENT""*************************************************************
* ID         		: ---
* Function name     : void RecTimer(void)
* Function     		: when the function is executed 16 times, 1 bit is received
* Paramenter   		: none
* Return 	 		: none
* Function used		: none
* Notice	   		: none
* History    		: ---
*""FUNC COMMENT END""*********************************************************/
void RecTimer(void)
{
	static revdata = 0;	// temperary data for receiving data

	if(!cStartBit)	// the start bit is not received
	{
		if(cReving==0 && !p9_0)	// some signal is received 
		{
			cReving = 1;	// set the flag for the character is receiving
			cRevTimerCount = 0;	// clear the count of times of RecTimer() executed
		}

		if(cReving==1 && cRevTimerCount>=IFR_BAUD/2) // sample the data at the center of receiving time
		{
			if(!p9_0)	// signal is received
			{
				cStartBit = 1;	// the start bit is received
				cRevBits = 0;	// set bit received as 0
				revdata	= 0;	// clear the temperary data for receiving data
				cRevTimerCount = 0;	// clear the count of times of RecTimer() executed
			}
			else	// it is noise
			{
				cReving =0;	// clear the flag for the character is receiving
				cRevTimerCount = 0;	// clear the count of times of RecTimer() executed
			}
		}
	}
	else	// the start bit is received
	{
		if (cRevTimerCount >= IFR_BAUD)	// the time to sample data
		{
			unsigned char rev = p9_0;

			if(cRevBits < 8)	// it is data bit
			{
				revdata += (rev << cRevBits);	// save data bit
				cRevBits ++;	// to receive the next bit
			}
			else	// it is stop bit
			{
				if (p9_0)	// the data is valid
				{
					CanRec = 1;		// set the flag for a character is received
					ucRecBuf = revdata;	// save the data received
				}

				cReving             = 0;	// clear the flag for the character is receiving
				cStartBit           = 0;	// clear the flag for start bit
				cRevBits            = 0;	// clear the count of bits received

			}

			cRevTimerCount = 0;	// clear the count of times of RecTimer() executed
		}
	}

	cRevTimerCount ++;	// increase the count of times of RecTimer() executed

}