Timer Control/Status Register (Tcsr) - Renesas H8S/2158 User Manual

Section 15 Watchdog Timer (WDT)
15.3.2

Timer Control/Status Register (TCSR)

TCSR selects the clock source to be input to TCNT, and the timer mode.
• TCSR_0
Bit Bit Name Initial Value R/W
7 OVF 0
6 WT/IT 0
5 TME 0
4 — 0
3 RST/NMI 0
Rev. 3.00 Jan 25, 2006 page 376 of 872
REJ09B0286-0300
Description
R/(W) * 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, then 0 is 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) Reserved
The initial value should not be changed.
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