Fujitsu MB90390 Series Hardware Manual page 157

Note:
Ceramic and crystal oscillators generally require an oscillation stabilization wait time of several
milliseconds, until stabilization at a natural frequency is attained. A proper oscillation stabilization
wait time must be set for the particular oscillator used.
See Section "5.5 Oscillation Stabilization Wait Time", for details about oscillation stabilization wait times.
■ Oscillation Stabilization Wait and Reset State
A reset operation in response to a power-on reset and other resets during stop mode is performed after the
oscillation stabilization wait time has elapsed. This time interval is generated by the time-base timer. If the
external reset has not been cleared after the interval, the reset operation is performed after the external reset
is cleared.
CHAPTER 7 RESETS
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