CHAPTER 20 CLOCK MONITOR
Preliminary User’s Manual U16315EJ1V0UD
363
Figure 20-3. Timing of Clock Monitor (1/3)
(1) When internal reset is executed by oscillation stop of X1 input clock
4 clocks of Ring-OSC clock
X1 input clock
Ring-OSC clock
Internal reset signal
CLME
CLMRF
Note
Note
CLMRF is read by software and then automatically cleared to 0. CLMRF is cleared under the following
conditions.
•
RESET input
•
Internal reset signal generation by POC
•
After read by software
(2) Clock monitor status after STOP mode is released
(CLME = 1 is set when CPU clock operates on X1 input clock and before entering STOP mode)
Clock monitor status
Monitoring
Monitoring stopped
Monitoring
CLME
Ring-OSC clock
X1 input clock
CPU operation
Normal
operation
STOP
Oscillation stabilization time
Normal operation
Oscillation
stopped
Oscillation stabilization time
(set by OSTS register)
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.