Chapter 5 Clock Generator; Functions Of Clock Generator - NEC 78K0/KD1 Series User Manual

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.
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.

CHAPTER 5 CLOCK GENERATOR

Preliminary User's Manual U16315EJ1V0UD
Oscillation cannot be stopped. When
103