CHAPTER 5 CLOCK GENERATORS
User’s Manual U18172EJ2V0UD
74
(a) The internal reset signal is generated by the power-on clear function on power application, the option byte is
referenced after reset, and the system clock is selected.
(b) The option byte is referenced and the system clock is selected. Then the high-speed internal oscillation
clock operates as the system clock.
Figure 5-9. Status Transition of Default Start by High-Speed internal oscillation
HALT
instruction
STOP
instruction
V
DD
> 2.1 V
±
0.1 V
Start with PCC = 02H,
PPCC = 02H
HALT
STOP
Interrupt
Reset signal
Interrupt
Power
application
Reset by
power-on clear
Clock division ratio
variable during
CPU operation
High-speed internal
oscillator selected
by option byte
Remark
PCC:
Processor clock control register
PPCC: Preprocessor clock control register