HD6473032F16 Datasheet, PDF (461/847 Pages) Renesas Technology Corp – Hardware Manual Renesas 16-Bit Single-Chip Microcomputer H8 Family/H8/300H Series

Section 12 Watchdog Timer
H'FF
TCNT count
value
H'00
Internal
reset signal
Start
WDT overflow
TME set to 1
OVF = 1
H'00 written
in TCNT
Reset
H'00 written
in TCNT
518 states
Figure 12.4 Watchdog Timer Operation
12.3.2 Interval Timer Operation
Figure 12.5 illustrates interval timer operation. To use the WDT as an interval timer, clear bit
WT/IT to 0 and set bit TME to 1 in TCSR. An interval timer interrupt request is generated at each
TCNT overflow. This function can be used to generate interval timer interrupts at regular
intervals.
H'FF
TCNT
count value
H'00
WT/ IT = 0
TME = 1
Interval
timer
interrupt
Interval
timer
interrupt
Interval
timer
interrupt
Interval
timer
interrupt
Figure 12.5 Interval Timer Operation
Time t
Rev. 3.00 Mar 21, 2006 page 431 of 814
REJ09B0302-0300