Renesas H8S/2158 User Manual page 432

Section 15 Watchdog Timer (WDT)
• TCSR_1
Bit Bit Name Initial Value R/W
7 OVF 0
6 WT/IT 0
5 TME 0
4 PSS 0
3 RST/NMI 0
Rev. 3.00 Jan 25, 2006 page 378 of 872
REJ09B0286-0300
Description
R/(W) * 1
Overflow Flag
Indicates that TCNT has overflowed (changes from H'FF
to H'00).
[Setting condition]
•
When TCNT overflows (changes from H'FF to H'00)
When internal reset request generation is selected in
watchdog timer mode, OVF is cleared automatically
by the internal reset.
[Clearing conditions]
When TCSR is read when OVF = 1 *
•
written to OVF
•
When 0 is written to TME
R/W Timer Mode Select
Selects whether the WDT is used as a watchdog timer
or interval timer.
0: Interval timer mode
1: Watchdog timer mode
R/W Timer Enable
When this bit is set to 1, TCNT starts counting.
When this bit is cleared, TCNT stops counting and is
initialized to H'00.
R/W Prescaler Select
Selects the clock source to be input to TCNT.
0: Counts the divided cycle of φ-based prescaler (PSM)
1: Counts the divided cycle of φSUB-based prescaler
(PSS)
R/W Reset or NMI
Selects to request an internal reset or an NMI interrupt
when TCNT has overflowed.
0: An NMI interrupt is requested
1: An internal reset is requested
2
, then 0 is