CHAPTER 5 CLOCK GENERATORS
Preliminary User’s Manual U16898EJ1V0UD
64
Figure 5-1. Block Diagram of Clock Generators
X1/P121
X2/P122
f
X
f
X
2
PCC1
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)
HSRSTOP
STOP
PPCC1 PPCC0
OSTS1 OSTS0
f
XP
2
2
f
XP
f
X
2
2
f
RL
LSRSTOP
f
RH
CPU
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 Ring-OSC
mode register (LSRCM)
High-speed Ring-OSC
mode register (HSRCM)
High-speed Ring-OSC
is selected as system
clock source
Clock for flash
memory self
programming
control
Low-speed
Ring-OSC
oscillator
Prescaler
System clock
oscillator
Note
External clock
input
Crystal/ceramic
oscillation
High-speed
Ring-OSC
oscillation
Note Select the high-speed Ring-OSC oscillator, crystal/ceramic oscillator, or external clock input as the system
clock source by using the option byte.
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