usart.h

PIC单片机模拟串口 11.0592时钟 支持2400波特及以下稳定收发 一位起始

#ifndef _SERIAL_H_
#define _SERIAL_H_


//9600  
#define BAUD 2400			    
//#define FOSC 12000000L
  #define FOSC 11059200L
//--------------------------------------------------

//Use 9bit communication? FALSE=8bit
#define NINE 0     			
#define HIGH_SPEED 0
//---------------------------------------------------

#if NINE == 1
#define NINE_BITS 0x40
#else
#define NINE_BITS 0
#endif
//--------------------------------------------------

#if HIGH_SPEED == 1
#define SPEED 0x4
#define DIVIDER ((int)(FOSC/(16UL * BAUD) -1))
#else
#define SPEED 0
#define DIVIDER ((int)(FOSC/(64UL * BAUD) -1))
#endif

#if defined(_16F87) || defined(_16F88)
	#define RX_PIN TRISB2
	#define TX_PIN TRISB5
#else
	#define RX_PIN TRISC7
	#define TX_PIN TRISC6
#endif
//--------------------------------------------------

//Serial initialization 
#define init_comms()\
	RX_PIN = 1;	\
	TX_PIN = 1;		  \
	SPBRG = DIVIDER;     	\
	RCSTA = (NINE_BITS|0x90);	\
	TXSTA = (SPEED|NINE_BITS|0x20)
//--------------------------------------------------

void putch(unsigned char);
unsigned char getch(void);
unsigned char getche(void);

#endif