HD6417144 RENESAS [Renesas Technology Corp], HD6417144 Datasheet - Page 430

• Manufacturer Part Number: HD6417144
• Description: 32-Bit RISC Microcomputer SuperHTM RISC engine Family/SH7144 Series
• Manufacturer: RENESAS [Renesas Technology Corp]

12. Watchdog Timer
12.4.2
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 (TCNT) overflows. This function can
be used to generate interval timer interrupts at regular intervals.
Rev.4.00 Mar. 27, 2008 Page 386 of 882
REJ09B0108-0400
Interval Timer Mode
Internal reset
signal*
WDTOVF
signal
WT/IT: Timer mode select bit
TME:
Note: * Internal reset signal occurs only when the RSTE bit is set to 1.
H'00
ITI: Interval timer interrupt request generation
H'FF
TCNT value
H'FF
H'00
Timer enable bit
TCNT value
WT/IT = 0
TME = 1
Figure 12.2 Operation in Watchdog Timer Mode
WT/IT = 1
TME = 1
Figure 12.3 Operation in Interval Timer Mode
Overflow
H’00 written
in TCNT
ITI
Overflow
WDTOVF and internal
reset generated
ITI
Overflow
WOVF = 1
128 φ clocks
512 φ clocks
Overflow
ITI
WT/IT = 1
TME = 1
Overflow
H’00 written
in TCNT
ITI
Time
Time