IP2022 User’s Manual—Peripherals www.ubicom.com 245 4.3 Real-Time Timer The  Real-Time  Timer  is  an  8-bit  timer  intended  to  provide  a
periodic  system  wake-up  interrupt.  Unlike  the  other  peripherals
(except the Watchdog Timer and port B interrupts), the Real-Time
Timer continues to function when the system clock is disabled. For
those applications which spend much of their time with the OSC
clock oscillator turned off to conserve power, there are only three
available  mechanisms  for  a  wake-up:  reset  from  the  Watchdog
Timer, interrupt from a Port B input, and interrupt from the Real-
Time Timer. By using an interrupt rather than reset, more of the
CPU  state  is  preserved  and  some  reset  procedures  such  as
initializing the port direction registers can be skipped. T0IF Timer 0 interrupt flag 0 =   No timer overflow has occurred since this bit was           last cleared
1 =   Timer overflow has occurred Name Description