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CHAPTER 21 CLOCK MONITOR
User’s Manual U16228EJ2V0UD
406
Figure 21-3. Timing of Clock Monitor (3/4)
(5) Clock monitor status after STOP mode is released
(CLME = 1 is set when CPU clock operates on Ring-OSC clock and before entering STOP mode)
Clock monitor status
Monitoring
Monitoring
stopped
Monitoring stopped
Monitoring
CLME
Ring-OSC clock
(CPU clock)
X1 input clock
CPU operation
Normal
operation
17 clocks
Clock supply
stopped
Normal operation
Oscillation
stopped
Oscillation stabilization time
(time set by OSTS register)
STOP
When bit 0 (CLME) of the clock monitor mode register (CLM) is set to 1 before entering STOP mode, monitoring
automatically starts at the end of the X1 input clock oscillation stabilization time. Monitoring is stopped in STOP mode
and during the oscillation stabilization time.
(6) Clock monitor status after X1 input clock oscillation is stopped by software
Normal operation (Ring-OSC clock or subsystem clock
Note
)
CPU operation
Clock monitor status
CLME
MSTOP or
MCC
Note
Ring-OSC clock
X1 input clock
Oscillation stabilization time
(time set by OSTS register)
Monitoring
Monitoring
stopped
Monitoring
Monitoring stopped
Oscillation
stopped
When bit 0 (CLME) of the clock monitor mode register (CLM) is set to 1 before or while oscillation of the X1 input
clock is stopped, monitoring automatically starts at the end of the X1 input clock oscillation stabilization time.
Monitoring is stopped when oscillation of the X1 input clock is stopped and during the oscillation stabilization time.
Note
The register that controls oscillation of the X1 input clock differs depending on the type of the clock supplied
to the CPU.
When CPU operates on Ring-OSC clock: Controlled by bit 7 (MSTOP) of the main OSC control
register (MOC)
When CPU operates on subsystem clock: Controlled by bit 7 (MCC) of the processor clock control
register (PCC)