
365
CHAPTER 21 ELECTRICAL SPECIFICATIONS
User
’
s Manual U15017EJ2V0UD
Main System Clock Oscillator Characteristics (T
A
=
40 to +85
°
C)
Resonator
Recommended Circuit
Parameter
Symbol
Conditions
MIN.
TYP.
MAX.
Unit
Ceramic
resonator or
crystal
Oscillation
frequency
f
X
4
12.5
MHz
resonator
Oscillation
stabilization time
Note
f
SX
When reset is
released
2
19
/f
XX
ns
When STOP mode
is released
Note
ns
External
Oscillation
f
X
ENMP = 0
8
25
MHz
clock
frequency
ENMP = 1
4
12.5
MHz
Oscillation
stabilization time
Note
f
SX
When reset is
released
2
19
/f
XX
ns
When STOP mode
is released
Note
ns
Input high-/low-level
width
t
WXH
,
t
WXL
18
125
ns
Input rising/falling time
t
XR
,
t
XF
0
5
ns
Note
The oscillation stabilization time is the time required for oscillation to stabilize after power (V
DD
) application.
Caution When using the main system clock 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 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
SS1
.
Do not ground the capacitor to a ground pattern through which a high current flows.
Do not fetch signals from the oscillator.
Remarks 1.
f
X
:
Main system clock oscillation frequency
f
XX
: Main system clock frequency
2.
For the resonator selection and oscillator constant, customers are requested to either evaluate the
oscillation themselves or apply to the resonator manufacturer for evaluation.
V
SS1
X1
X2
C2
C1
X1
X2
HCMOS
inverter