SH7058 Datasheet, PDF (487/1130 Pages) Renesas Technology Corp – Renesas SuperHTM RISC engine

13.3.2 Interval Timer Mode
To use the WDT as an interval timer, clear WT/IT to 0 and set TME to 1 in TCSR. An interval
timer interrupt (ITI) is generated each time the timer counter overflows. This function can be used
to generate interval timer interrupts at regular intervals (figure 13.5).
TCNT value
H'FF
Overflow
Overflow
Overflow
Overflow
H'00
WT/IT = 0
ITI
ITI
ITI
ITI
TME = 1
ITI: Interval timer interrupt request generation
Figure 13.5 Operation in Interval Timer Mode
Time
13.3.3 Timing of Setting the Overflow Flag (OVF)
In interval timer mode, when TCNT overflows, the OVF flag in TCSR is set to 1 and an interval
timer interrupt (ITI) is simultaneously requested (figure 13.6).
CK
TCNT
H'FF H'00
Overflow signal
(internal signal)
OVF
Figure 13.6 Timing of Setting OVF
Rev. 3.0, 09/04, page 446 of 1086