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CHAPTER 5 CLOCK GENERATOR
User’s Manual U19780EJ2V0UD
131
Remark
f
X
:
X1 clock oscillation frequency
f
RH
:
Internal high-speed oscillation clock frequency
f
EXCLK
:
External main system clock frequency
f
XH
:
High-speed system clock frequency
f
XP
:
Main system clock frequency
f
PRS
:
Peripheral hardware clock frequency
f
CPU
:
CPU clock frequency
f
XT
:
XT1 clock oscillation frequency
f
SUB
:
Subsystem clock frequency
f
RL
:
Internal low-speed oscillation clock frequency
5.3 Registers Controlling Clock Generator
The following seven registers are used to control the clock generator.
•
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)
(1) Clock operation mode select register (OSCCTL)
This register selects the operation modes of the high-speed system and subsystem clocks, and the gain of the
on-chip oscillator.
OSCCTL can be set by a 1-bit or 8-bit memory manipulation instruction.
Reset signal generation clears this register to 00H.