R01UH0822EJ0100 Rev.1.00
Page 565 of 1041
Jul 31, 2019
RX13T Group
22. Independent Watchdog Timer (IWDTa)
22.2
Register Descriptions
22.2.1
IWDT Refresh Register (IWDTRR)
The IWDTRR register refreshes the counter of the IWDT.
The counter of the IWDT is refreshed by writing 00h and then writing FFh to the IWDTRR register (refresh operation)
within the refresh-permitted period.
After the counter has been refreshed, it starts counting down from the value selected by the IWDTTOPS[1:0] bits in
option function select register 0 (OFS0) in auto-start mode. In register start mode, counting down starts from the value
selected by setting the IWDTCR.TOPS[1:0] bits in the first refresh operation after a reset is released.
When 00h is written, the read value is 00h. When a value other than 00h is written, the read value is FFh.
For details of the refresh operation, refer to
section 22.3.3, Refresh Operation
Address(es): IWDT.IWDTRR 0008 8030h
b7
b6
b5
b4
b3
b2
b1
b0
Value after reset:
1
1
1
1
1
1
1
1
Bit
Description
R/W
b7 to b0
The counter is refreshed by writing 00h and then writing FFh to this register.
R/W