CHAPTER 5 CLOCK GENERATOR
Preliminary User’s Manual U16315EJ1V0UD
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5.3 Registers Controlling Clock Generator
The following six registers are used to control the clock generator.
•
Processor clock control register (PCC)
•
Ring-OSC mode register (RCM)
•
Main clock mode register (MCM)
•
Main OSC control register (MOC)
•
Oscillation stabilization time counter status register (OSTC)
•
Oscillation stabilization time select register (OSTS)
(1) Processor clock control register (PCC)
The PCC register is used to select the CPU clock, the division ratio, main system clock oscillator operation/stop
and whether to use the on-chip feedback resistor of the subsystem clock oscillator.
The PCC is set by a 1-bit or 8-bit memory manipulation instruction.
RESET input clears PCC to 00H.
Figure 5-2. Subsystem Clock Feedback Resistor
FRC
P-ch
Feedback resistor
XT1
XT2