MC9S08SG8 Datasheet, PDF (197/310 Pages) Freescale Semiconductor, Inc – Microcontrollers

/* Initialize the elapsed time counters */
Seconds = 0;
Minutes = 0;
Hours = 0;
Days=0;
Real-Time Counter (S08RTCV1)
/* Configure RTC to interrupt every 1 second from 1-kHz clock source */
RTCMOD.byte = 0x00;
RTCSC.byte = 0x1F;
/**********************************************************************
Function Name : RTC_ISR
Notes : Interrupt service routine for RTC module.
**********************************************************************/
#pragma TRAP_PROC
void RTC_ISR(void)
{
/* Clear the interrupt flag */
RTCSC.byte = RTCSC.byte | 0x80;
/* RTC interrupts every 1 Second */
Seconds++;
/* 60 seconds in a minute */
if (Seconds > 59){
Minutes++;
Seconds = 0;
}
/* 60 minutes in an hour */
if (Minutes > 59){
Hours++;
Minutes = 0;
}
/* 24 hours in a day */
if (Hours > 23){
Days ++;
Hours = 0;
}
}
MC9S08SG8 MCU Series Data Sheet, Rev. 0
Freescale Semiconductor
197