CHAPTER 9 WATCH TIMER FUNCTION
User’s Manual U15109EJ3V0UD
315
9.4.3 Cautions
It takes some time to generate the first watch timer interrupt request (INTWTN) after operation is enabled (WTNM1
and WTNM0 bits of WTNM register = 1).
Figure 9-3. Watch Timer Interrupt Request (INTWTN) Generation (Interrupt Period = 0.5 s)
It takes 0.515625 s to generate the first INTWTN (2
9
×
1/32.768 = 0.015625 s longer). INTWTN is then
generated every 0.5 s.
0.5 s
0.5 s
0.515625 s
WTNM0, WTNM1
INTWTN