Fujitsu FR81S User Manual
CHAPTER 34: CLOCK SUPERVISOR
4. Operation
FUJITSU SEMICONDUCTOR LIMITED
CHAPTER : CLOCK SUPERVISOR
FUJITSU SEMICONDUCTOR CONFIDENTIAL
15
4.6. Watch Mode
This section explains watch mode.
Main Clock Supervisor
The main clock supervisor function is not influenced from the transition to the watch mode.
When the main clock stops, the change dividing and reset are issued to the CR oscillation clock when the
main clock is connected with the permission of the main clock supervisor function and RTC.
The watch mode is made clear, and RTC is initialized.
The RTC clock stops only because it does not detect it even if the main clock stops when the main clock is
connected with the prohibition of the main clock supervisor function and RTC.
Sub Clock Supervisor
The sub clock supervisor function is not influenced from the transition to the watch mode.
When a sub clock is connected with the permission of the sub clock supervisor function and RTC, reset is
not issued though it cuts in the CR oscillation clock when a sub clock stops.
The RTC clock stops only because it does not detect it even if the sub clock stops when the sub clock is
connected with the prohibition of the sub clock supervisor function and RTC.
MB91520 Series
MN705-00010-1v0-E
1188