Datasheet

78K0/Kx2-L CHAPTER 5 CLOCK GENERATOR
R01UH0028EJ0400 Rev.4.00 199
Sep 27, 2010
(3) Internal low-speed oscillation clock (clock for watchdog timer)
• Internal low-speed oscillator
This circuit oscillates a clock of f
IL = 30 kHz (TYP.). After a reset release, the internal low-speed oscillation clock
always starts operating.
Oscillation can be stopped by using the internal oscillation mode register (RCM) when “internal low-speed
oscillator can be stopped by software” is set by option byte.
The internal low-speed oscillation clock cannot be used as the CPU clock. The following hardware operates with
the internal low-speed oscillation clock.
• Watchdog timer
• 8-bit timer H1 (when f
IL, fIL/2
6
, or fIL/2
15
is selected)
Remark f
IL: Internal low-speed oscillation clock frequency
5.2 Configuration of Clock Generator
The clock generator includes the following hardware.
Table 5-1. Configuration of Clock Generator
Item Configuration
Control registers Clock operation mode select register (OSCCTL)
Processor clock control register (PCC)
Internal oscillation mode register (RCM)
Main OSC control register (MOC)
Main clock mode register (MCM)
Oscillation stabilization time counter status register (OSTC)
Oscillation stabilization time select register (OSTS)
Oscillators X1 oscillator
XT1 oscillator
Note
Internal high-speed oscillator
Internal low-speed oscillator
Note 78K0/KC2-L only