Datasheet

CHAPTER 27 ELECTRICAL SPECIFICATIONS (STANDARD PRODUCTS)
User’s Manual U18698EJ1V0UD
543
Standard
p
roducts
X1 Oscillator Characteristics
(TA = −40 to +85°C, 1.8 V ≤ VDD ≤ 5.5 V, VSS = AVSS = 0 V)
Resonator Recommended Circuit Parameter Conditions MIN. TYP. MAX. Unit
2.7 V ≤ VDD ≤ 5.5 V 2.0 10.0
Ceramic
resonator
C1
X2X1
VSS
C2
X1 clock
oscillation
frequency (f
X)
Note
1.8 V ≤ V
DD < 2.7 V 2.0 5.0
MHz
2.7 V ≤ VDD ≤ 5.5 V 2.0 10.0
Crystal
resonator
C1
X2X1
C2
VSS
X1 clock
oscillation
frequency (f
X)
Note
1.8 V ≤ V
DD < 2.7 V 2.0 5.0
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.
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.