keyboard.c

基于51的单片机的PPP协议实现

#include <iogp20.h>
#include "Keyboard.h"

volatile BYTE Key = 0;

void KeyboardStart (void) {
	//////////////// Keyboard Initialization ////////////////
	INTKBSCR |= KB_IMASKK;
	INTKBSCR &= ~(KB_MODEK);
	DDRA = 0xF8;
	PTAPUE = 0x06; //Attach internal pullups for buttons

	INTKBIER = 0x06; //Register Key 1 and 2
	INTKBSCR &= ~(KB_ACK);
	
	INTKBSCR &= ~(KB_IMASKK); //Enable interrupts
}


#if HIWARE
interrupt 15 void KeyboardISR (void) {
#else
@interrupt void KeyboardISR (void) {
#endif

	INTKBSCR |= KB_ACK;

	if (Key) return;
	
	if (PORTA & KB_KEY1) {
		Key = KB_KEY1;
	}
	if (PORTA & KB_KEY2) {
		Key = KB_KEY2;
	}
}