Fujitsu FR81S Manuale Utente
CHAPTER 34: CLOCK SUPERVISOR
4. Operation
FUJITSU SEMICONDUCTOR LIMITED
CHAPTER : CLOCK SUPERVISOR
FUJITSU SEMICONDUCTOR CONFIDENTIAL
13
4.4. Sub Clock Mode
This section explains the sub clock mode of the clock supervisor.
The main clock supervisor function stops automatically when the device changes to the sub clock mode
with the main clock supervisor function has been permitted.
The main clock supervisor enable bit (CSVCR:MSVE) does not become "0".
After the oscillation stabilization wait time of the main clock passes, the main clock supervisor function is
permitted again when the device changes from the sub-clock mode to the main clock mode.
[Notes]
Because the main oscillation stabilization wait time is measured by the main clock itself, if the main clock
stops before the oscillation stabilization wait time has elapsed, the main oscillation stabilization wait time
does not end and the main clock supervisor is not enabled.
In this case, after the timeout time measured by the internal CR oscillator has elapsed, the main clock
supervisor function is enabled regardless of the oscillation stabilization wait time and the main clock stop is
detected.
MB91520 Series
MN705-00010-1v0-E
1186