R01UH0823EJ0100 Rev.1.00
Page 146 of 1823
Jul 31, 2019
RX23W Group
6. Resets
6.3.7
Determination of Cold/Warm Start
By reading the CWSF flag in RSTSR1, the type of reset processing caused can be identified; that is, whether a power-on
reset has caused the reset processing (cold start) or a reset signal input during operation has caused the reset processing
(warm start).
The CWSF flag in RSTSR1 is set to 0 when a power-on reset occurs (cold start); otherwise the flag is not set to 0. The
flag is set to 1 when 1 is written to it through programming; it is not set to 0 even when 0 is written.
shows an example of cold/warm start determination operation.
Figure 6.3
Example of Cold/Warm Start Determination Operation
VPOR
External voltage VCC
RES# pin
POR detection signal
(Low is valid)
RSTSR1.CWSF flag
Set to 1 through programming
Not driven to 0 when a
low level is applied to
the RES# pin