
CHAPTER 4 CLOCK GENERATOR
87
(2) When the device is powered on, and when restoring from the STOP mode, sufficient time must be allowed for the oscillation
to stabilize. Generally speaking, the time required for oscillation stabilization is several milliseconds when a crystal
resonator is used, and several hundred microseconds when a ceramic resonator is used.
An adequate oscillation stabilization period should be secured by the following means:
<1>
<2>
When powering-on
When returning from STOP mode :
(i)
RESET input (reset period)
(ii) Time of the oscillation stabilization timer that automatically starts at the valid edge of NMI, INTP4, or INTP5
signal
Note
(set by the oscillation stabilization time specification register (OSTS))
: RESET input (reset period)
Note
For INTP4 and INTP5, when masking is released and macro service is disabled.
(3) The EXTC bit of the oscillation stabilization time specification register (OSTS) must be cleared (to 0). If the EXTC bit is set
(to 1), oscillation will stop.