CHAPTER 5 CLOCK GENERATOR
User’s Manual U16899EJ2V0UD
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Table 5-3. Relationship Between Operation Clocks in Each Operation Status
High-Speed System
Clock Oscillator
Ring-OSC Oscillator
Note 2
Prescaler Clock
Supplied to Peripherals
Status
Operation
Mode
MSTOP = 0
MCC = 0
MSTOP = 1
MCC = 1
Note 1
RSTOP = 0 RSTOP = 1
Subsystem
Clock
Oscillator
CPU Clock
After
Release
MCM0 = 0 MCM0 = 1
Reset Stopped
Ring-OSC
Stopped
STOP
Stopped
Note 3
Stopped
HALT Oscillating
Stopped
Oscillating
Oscillating
Stopped
Oscillating
Note 4
Ring-OSC High-
speed
system
clock
Notes 1. When “Cannot be stopped” is selected for Ring-OSC by the option byte.
2. When “Can be stopped by software” is selected for Ring-OSC by the option byte.
3. Operates using the CPU clock at STOP instruction execution.
4. Operates using the CPU clock at HALT instruction execution.
Caution The RSTOP setting is valid only when “Can be stopped by software” is set for Ring-OSC by the
option byte.
Remark MSTOP: Bit 7 of the main OSC control register (MOC)
MCC:
Bit 7 of the processor clock control register (PCC)
RSTOP: Bit 0 of the Ring-OSC mode register (RCM)
MCM0:
Bit 0 of the main clock mode register (MCM)
Table 5-4. Oscillation Control Flags and Clock Oscillation Status
High-Speed System Clock Oscillator
Ring-OSC Oscillator
RSTOP = 0
Stopped
Oscillating
MSTOP = 1
Note
RSTOP = 1
Setting prohibited
RSTOP = 0
Oscillating
MSTOP = 0
Note
RSTOP = 1
Oscillating
Stopped
RSTOP = 0
Oscillating
MCC = 1
Note
RSTOP = 1
Stopped
Stopped
RSTOP = 0
Oscillating
MCC = 0
Note
RSTOP = 1
Oscillating
Stopped
Note Setting high-speed system clock oscillator oscillating/stopped differs depending on the CPU clock
used.
•
When the Ring-OSC clock is used as the CPU clock: Set using the MSTOP bit
•
When the subsystem clock is used as the CPU clock: Set using the MCC bit
Caution The RSTOP setting is valid only when “Can be stopped by software” is set for Ring-OSC
by the option byte.
Remark MSTOP: Bit 7 of the main OSC control register (MOC)
MCC:
Bit 7 of the processor clock control register (PCC)
RSTOP: Bit 0 of the Ring-OSC mode register (RCM)