R01UH0823EJ0100 Rev.1.00
Page 821 of 1823
Jul 31, 2019
RX23W Group
30. Watchdog Timer (WDTA)
30.2
Register Descriptions
30.2.1
WDT Refresh Register (WDTRR)
WDTRR refreshes the down-counter of the WDT.
The down-counter of the WDT is refreshed by writing 00h and then writing FFh to WDTRR (refresh operation) within
the refresh-permitted period.
After the down-counter has been refreshed, it starts counting down from the value selected by setting the
WDTTOPS[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 WDTCR.TOPS[1:0] bits.
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 30.3.3, Refresh Operation
Address(es): 0008 8020h
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 down-counter is refreshed by writing 00h and then writing FFh to this register
R/W