R01UH0823EJ0100 Rev.1.00
Page 835 of 1823
Jul 31, 2019
RX23W Group
31. Independent Watchdog Timer (IWDTa)
To use the IWDT, the IWDT-dedicated clock (IWDTCLK) should be supplied so that the IWDT operates even if the
peripheral module clock (PCLK) stops. The bus interface and registers operate with PCLK, and the 14-bit counter and
control circuits operate with IWDTCLK.
is a block diagram of the IWDT.
Figure 31.1
IWDT Block Diagram
IWDT control circuit
14-bit counter
IWDTRR:
IWDT refresh register
IWDTCR:
IWDT control register
IWDTSR:
IWDT status register
IWDTRCR: IWDT reset control register
IWDTCSTPR: IWDT count stop control register
IWDT reset output
IW
D
T
C
S
T
P
R
Option function select register 0
(OFS0)
IWDTCLK
IWDTCLK/16
IWDTCLK/64
IWDTCLK/32
IWDTCLK/128
IWDTCLK/256
Reset control circuit
Interrupt control circuit
Clock control circuit
Count stop control output
in sleep mode
Clock
frequency
divider
IWDTCLK
Internal peripheral bus
IW
D
T
RCR
IW
D
T
SR
IWDT
C
R
IWDT
R
R
Event link controller
Event signal output
Interrupt request (WUNI)