R01UH0823EJ0100 Rev.1.00
Page 844 of 1823
Jul 31, 2019
RX23W Group
31. Independent Watchdog Timer (IWDTa)
Figure 31.3
Operation Example in Register Start Mode
Refresh-
prohibited
period
(1)
(2)
(2)
(2)
(1) Initial value
(2) Set value
Status flag
cleared
Status flag
cleared
Counter value
Refresh-
permitted
period
Refresh-
prohibited
period
100%
75%
50%
25%
0%
RES# pin
IWDTCR
register
Refresh
the counter
(active high)
REFEF flag
UNDFF flag
Reset output
from IWDT
(active high)
Counting starts
Counting starts
Counting starts
Writing to the
register is valid.
H
H
L
H
L
Writing to the
register is invalid.
Underflow
Refresh error
Writing to the
register is invalid.
Refresh error
Interrupt request
(WUNI)
(active low)