How-To Guide

Table Of Contents
R01UH0823EJ0110 Rev.1.10 Page 829 of 1852
Nov 30, 2020
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:
11111111
Bit Description R/W
b7 to b0 The down-counter is refreshed by writing 00h and then writing FFh to this register R/W