MC81F4332 Datasheet, PDF (110/198 Pages) Finechips – ABOV SEMICONDUCTOR 8-BIT SINGLE-CHIP MICROCONTROLLERS

MC81F4x16
17. WATCH TIMER
Watch timer functions include real-time and watch-time measurement and interval timing for the
system clock.
Watch timer has the following functional components:
- Real time and watch time measurement
- Using a main or sub clock source (main clock divided by 2⁷(fx/128) or sub clock(fxt))
- Timing tests in high-speed mode
- Watch timer interrupt generation
- Watch timer status and control register (WTSCR)
WTEN ^{Enable/Disable}
fxx/128
fxt
Clock
Selector
fw
32.768KHz
60.0S
30.0S
Frequency 1.0S
Dividing 0.5S
Circuit _0.25S
10mS
Selector
Circuit
WTSC
WTSS
fxx = System clock (where fx = 4.19MHz)
fxt = Sub clock (32.768KHz)
fw = Watch timer Frequency
WTIE
Watch timer INT enable
WTIR
WTINT
Watch timer INT request
Figure 17-1 Watch Timer Block Diagram
110
October 19, 2009 Ver.1.35