serial.c

移植于51单片机上的ucos。SCH51-OS是整个工程项目

#include "typedef.h"
#include "ExtDef.h"

#define LenTxBuf	2000
#define LenRxBuf	50
#define MaxLenStr	100
#define TABNum 		8

uchar xdata TxBuf[LenTxBuf],RxBuf[LenRxBuf];  // buffer entities,缓冲区实体
uchar xdata *inTxBuf,*outTxBuf,*inRxBuf,*outRxBuf; // buffer pointers,缓冲区指针
uchar TIflag;
uchar RIflag;


void InitSerialBuffer(void)
{
	inTxBuf = TxBuf;
	outTxBuf = TxBuf;
	inRxBuf = RxBuf;
	outRxBuf = RxBuf+LenRxBuf-1;
}

void InitSerial(unsigned char BaudRate) 
{
	unsigned char THTL;
	switch (BaudRate)
	{
		case 1: THTL = 64; break; //波特率300
		case 2: THTL = 160; break; //600
		case 3: THTL = 208; break; //1200
		case 4: THTL = 232; break; //2400
		case 5: THTL = 244; break; //4800
		case 6: THTL = 250; break; //9600
		case 7: THTL = 253; break; //19200
		case 8: THTL = 255; break; //57600
		default: THTL = 208;
	}
	/* SCON = 0x52; set TI to 1, this is important for printf();if SCON=0x50,printf() function doesn't work!*/
	SCON = 0x52; //串口方式1,允许接收  ; SM0|SM1|SM2|REN|TB8|RB8|TI|RI , 
				// SM0|SM1 used to define work mode;   00:Mode0(SPI); 
				//											01:Mode1,8bit URAT(T1 Band Generator);
				//									       10:Mode2,9bit URAT(Bandrate fsoc/64,fsoc/32;
				//											11:Mode3,9bit URAT(T1 Bandrate Generator);
				// SM2=1:multi machines communication;
				// REN=1: Receive enable;
				// TB8: the TX nineth bit;   RB8: the RX  nineth bit
	TMOD = 0x20; //定时器1定时方式2; Gate | C/T | M1 | M0 | Gate | C/T | M1 | M0 
				//  Gate:external start/stop control , controlled by P3.2(INT0) or P3.3(INT1) 
				// C/T: =0:internal timer ; =1:external counter;
				// M1|M0: 00: 13bits counter/timer;
				//		   01: 16bits counter/timer;
				//		   10: auto reload 8bits counter/timer;
				//		   11: only fits to T0;two 8bits counter/timer; 
	TCON = 0x00;
	TH1 = THTL;
	TL1 = THTL;
	PCON = 0x80; //波特率加倍控制,SMOD位
	ES = 1; // enable URAT interrupt.
	TR1 = 1; //启动定时器 
}


void PrintChar(uchar ch)
{
	uchar *t;
	t=inTxBuf; t++;
	if(t==TxBuf+LenTxBuf) 
		t=TxBuf; //Rotate pointer 
	if(t==outTxBuf)
		return;		//Tx Buffer is full
	*inTxBuf = ch;
	inTxBuf = t;
	if(TIflag)
	{
		TIflag = 0;
		TI=1;
	}
}

void PrintStr(uchar *str)
{
	uchar i;
	uchar j;
	uchar ch;
	for(i=0;i<MaxLenStr;i++)
	{
		ch=*(str+i);
		if(ch=='\0') 	
			break;
		else
			if(ch=='\n')
			{
				PrintChar(10);
				PrintChar(13);
			}			
			else
				if(ch=='\t')
				{
					for(j=0;j<TABNum;j++)
						PrintChar(' ');
				}
		else
			PrintChar(ch);
	}
}

void clrscr()
{
	PrintStr("\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n");
}

void serial() 
{
	uchar *t;
	if(TI)
	{
		TI=0;
		if(inTxBuf==outTxBuf)
		{
			TIflag=1;
			return;
		}			   			// Tx buffer is empty.
		SBUF = *outTxBuf;
		outTxBuf++;
		if(outTxBuf==TxBuf+LenTxBuf)
			outTxBuf=TxBuf;
	}
	if(RI)
	{
		RI=0;
		if(!RIflag)
			RIflag=1;
		t=inRxBuf;
		t++;
		if(t==RxBuf+LenRxBuf)	t=RxBuf;
		if(t==outRxBuf)	return;  // Rx buffer is full.
		*inRxBuf=SBUF;
		inRxBuf=t;
	}
}

void URAT_ISR() interrupt 4
{
	serial();
}