Preliminary User’s Manual U16315EJ1V0UD
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CHAPTER 5 CLOCK GENERATOR
5.1 Functions of Clock Generator
The clock generator generates the clock to be supplied to the CPU and peripheral hardware.
The following three system clock oscillators are available.
•
X1 oscillator
The X1 oscillator oscillates a clock of 2.0 to 10.0 MHz. Oscillation can be stopped by executing the STOP
instruction or setting the main OSC control register (MOC) and processor clock control register (PCC).
•
Ring-OSC oscillator
The Ring-OSC oscillator oscillates a clock of 240 kHz (TYP.). Oscillation can be stopped by setting the Ring-
OSC mode register (RCM) when “Can be stopped by software” is set by a mask option and the X1 input clock is
used as the CPU clock.
•
Subsystem clock oscillator
The subsystem clock oscillator oscillates a clock of 32.768 kHz. Oscillation cannot be stopped. When
subsystem clock oscillator is not used, setting not to use the on-chip feedback resistor is possible using the
processor clock control register (PCC), and the power consumption can be reduced in the STOP mode.