CHAPTER 28 ELECTRICAL SPECIFICATIONS
User’s Manual U16896EJ2V0UD
657
Main Clock Oscillator Characteristics
(1) Crystal resonator, ceramic resonator (T
A
=
−
40 to +85
°
C, V
DD
= 2.7 to 5.5 V, V
SS
= 0 V)
Recommended Circuit
Parameter
Conditions
MIN.
TYP.
MAX.
Unit
V
DD
= 4.5 to 5.5 V
2
5
MHz
V
DD
= 4.0 to 5.5 V
2
4
MHz
PLL mode
V
DD
= 2.7 to 5.5 V
2
2.5
MHz
Oscillation
frequency (f
X
)
Note 1
Clock-through mode V
DD
= 2.7 to 5.5 V
2
10
MHz
When OSTS0
Note 3
= 0
2
13
/f
X
s
After reset is
released
When OSTS0
Note 3
= 1
2
15
/f
X
s
X2
X1
Oscillation
stabilization
time
Note 2
After STOP mode is released
Note 4
s
Notes 1.
Indicates only oscillator characteristics.
2.
Time required to stabilize the resonator after reset or STOP mode is released.
3.
Set by mask option/option byte (refer to
CHAPTER 25
).
4.
The value differs depending on the OSTS register settings.
(2) External clock (T
A
=
−
40 to +85
°
C, V
DD
= 2.7 to 5.5 V, V
SS
= 0 V)
Recommended Circuit
Parameter
Conditions
MIN.
TYP.
MAX.
Unit
V
DD
= 4.5 to 5.5 V
2
5
MHz
V
DD
= 4.0 to 5.5 V
2
4
MHz
PLL mode
V
DD
= 2.7 to 5.5 V
2
2.5
MHz
External clock
X2
X1
Input frequency
(f
X
)
Note
Clock-through mode V
DD
= 2.7 to 5.5 V
2
10
MHz
Note
The duty ratio of the input waveform must be within 50%
±
5%.
Cautions 1. When using the main 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 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. When the main clock is stopped and the device is operating on the subclock, wait until the
oscillation stabilization time has been secured by the program before switching back to the
main clock.
