CHAPTER 5 CLOCK GENERATORS
User’s Manual U16898EJ3V0UD
68
Figure 5-1. Block Diagram of Clock Generators
X1/P121
X2/P122
f
X
f
X
2
PCC1
C
P
U
STOP
PPCC1 PPCC0
OSTS1 OSTS0
f
XP
2
2
f
XP
f
X
2
2
f
RL
LSRSTOP
Controller
Selector
CPU clock
(f
CPU
)
Internal bus
Internal bus
Oscillation stabilization
time select register (OSTS)
Preprocessor clock
control register (PPCC)
Processor clock
control register (PCC)
System clock oscillation
stabilization time counter
Selector
Prescaler
Clock to peripheral
hardware (f
XP
)
8-bit timer H1,
watchdog timer
Option byte
1: Cannot be stopped.
0: Can be stopped.
Low-speed internal oscillation
mode register (LSRCM)
Low-speed
internal
oscillator
Prescaler
System clock
oscillator
Note
External clock
input
Crystal/ceramic
oscillation
High-speed
internal
oscillation
Watchdog timer
Note
Select the high-speed internal oscillator, crystal/ceramic oscillator, or external clock input
circuit
as the
system clock source by using the option byte.