Fujitsu FR81S User Manual
CHAPTER 34: CLOCK SUPERVISOR
4. Operation
FUJITSU SEMICONDUCTOR LIMITED
CHAPTER : CLOCK SUPERVISOR
FUJITSU SEMICONDUCTOR CONFIDENTIAL
11
4.2. Stopping CR Oscillator and the Clock Supervisor
Function
This section explains stopping CR oscillator and the clock supervisor function.
CR Oscillator
The CR oscillator can be stopped only at the standby mode. Please change to the standby mode after setting
oscillation permission bit (CSVCR:RCE) at the standby mode to "0".
The thing to stop the CR oscillator when there is a problem in the main clock or a sub-clock is prohibited. It
can be confirmed whether or not the problem exists in the clock by the MM bit and the SM bit of the
CSVCR register.
[Note]
The operation clock stops, too, when the CR oscillation is stopped because the operation clock has already
replaced the CR oscillation clock when there is a problem in the clock.
Main Clock Supervisor
The MSVE bit of the CSVCR register is set to "0".
Sub Clock Supervisor
The SSVE bit of the CSVCR register is set to "0".
MB91520 Series
MN705-00010-1v0-E
1184