#include void MSDelay(unsigned int); void main(void) { DDRB = 0xFF; DDRA = 0xFF; PORTB = 0x55; PORTA = 0xAA; while(1) { PORTB = ~PORTB; PORTA = ~PORTA; MSDelay(250); } } void MSDelay(unsigned int itime) { unsigned int i; unsigned int j; for(i=0;i