CHAPTER 22 ELECTRICAL SPECIFICATIONS (TARGET)
Preliminary User’s Manual U19014EJ1V0UD
488
X1 Oscillator Characteristics
(T
A
=
−
40 to +85
°
C, 4.0 V
≤
V
DD
= EV
DD
≤
5.5 V, V
SS
= EV
SS
= 0 V)
Resonator Recommended
Circuit
Parameter
Conditions
MIN. TYP. MAX. Unit
Ceramic
resonator
C1
X2
X1
V
SS
C2
X1 clock
oscillation
frequency (f
X
)
Note
4.0 V
≤
V
DD
≤
5.5 V
16.0
MHz
Crystal
resonator
C1
X2
X1
V
SS
C2
X1 clock
oscillation
frequency (f
X
)
Note
4.0 V
≤
V
DD
≤
5.5 V
16.0
MHz
Note
Indicates
only
oscillator
characteristics. Refer to
AC Characteristics
for instruction execution time.
Cautions 1. When using the X1 oscillator, wire as follows in the area enclosed by the broken lines in the
above figures to avoid an adverse effect from wiring capacitance.
• Keep the wiring length as short as possible.
• Do not cross the wiring with the other signal lines.
• Do not route the wiring near a signal line through which a high fluctuating current flows.
• Always make the ground point of the oscillator capacitor the same potential as V
SS
.
• Do not ground the capacitor to a ground pattern through which a high current flows.
• Do not fetch signals from the oscillator.
2. Since the CPU is started by the internal high-speed oscillation clock after a reset release, check
the X1 clock oscillation stabilization time using the oscillation stabilization time counter status
register (OSTC) by the user. Determine the oscillation stabilization time of the OSTC register
and oscillation stabilization time select register (OSTS) after sufficiently evaluating the
oscillation stabilization time with the resonator to be used.
In addition, make sure that V
DD
≥
4.0 V before switching the CPU clock to the X1 clock.
Remark
For the resonator selection and oscillator constant, customers are requested to either evaluate the
oscillation themselves or apply to the resonator manufacturer for evaluation.
electronic components distributor
