Advertisement
M16C/5L Group, M16C/56 Group
13.4.3
Count Source Protection Mode Enabled
When the count source protection mode is enabled, fWDT is used as the watchdog timer count source.
Table 13.4 lists the specifications of the watchdog timer when the count source protection mode is
enabled.
Table 13.4
Watchdog Timer Specifications (When Count Source Protection Mode is Enabled)
Item
Count source
Count operation
Watchdog timer
cycle
Watchdog timer
counter refresh
timing
Count start
conditions
Count stop condition
Operations when the
watchdog timer
underflows
The dedicated 125 kHz on-chip oscillator for the watchdog timer (fWDT) is used as the watchdog timer
count source when the count source protection mode is enabled.
The dedicated 125 kHz on-chip oscillator for the watchdog timer (fWDT) automatically oscillates when
the CSPRO bit in the CSPR register is 1 (count source protection mode enabled).
R01UH0127EJ0110 Rev.1.10
Sep 01, 2011
fWDT
Decrements
m: The value set by setting bits WDTUFS1 and WDTUFS0 in the OFS2 address.
Example: When bits WDTUFS1 to WDTUFS0 are 00b (watchdog timer cycle setting
is 03FFh), the watchdog timer cycle is approximately 8.2 ms.
•
Resets (refer to 6. "Resets" for details)
•
Write 00h, and then FFh to the WDTR register.
•
Watchdog timer underflow
Set the WDTON bit in the OFS1 address to select the watchdog timer operation
after reset.
•
When the WDTON bit is set to 1 (watchdog timer is in stop state after reset):
The watchdog timer and prescaler stop after reset and the count starts by writing
to the WDTS register.
•
When the WDTON bit is set to 0 (watchdog timer starts automatically after reset):
The watchdog timer and prescaler start counting automatically after reset.
None.
Count continues even in wait mode once the count starts. The MCU does not enter
stop mode.
The watchdog timer is reset. (refer to 6.4.7 "Watchdog Timer Reset" for details)
Specification
Watchdog timer count value (m)
------------------------------------------------------------------------------------ -
fWDT
13. Watchdog Timer
Page 209 of 803
Advertisement
