upd78f0124hgba1-8et-a Renesas Electronics Corporation., upd78f0124hgba1-8et-a Datasheet - Page 445

• Manufacturer Part Number: upd78f0124hgba1-8et-a
• Description: 8-bit Single-chip Microcontrollers
• Manufacturer: Renesas Electronics Corporation.

Internal Oscillator Characteristic
Subsystem Clock Oscillator Characteristics
(T
Notes 1. Indicates only oscillator characteristics. Refer to AC Characteristics for instruction execution time.
Cautions 1. When using the subsystem clock oscillator, wire as follows in the area enclosed by the broken
Remark For the resonator selection and oscillator constant, customers are requested to either evaluate the
(T
On-chip internal oscillator
Crystal
resonator
External clock
Note2
A
A
Parameter
= −40 to +110°C, 2.7 V ≤ V
= −40 to +110°C, 2.0 V ≤ V
2. Input a clock signal to the XT1 pin and input the inverse clock signal to the XT2 pin.
2. The subsystem clock oscillator is designed as a low-amplitude circuit for reducing power
oscillation themselves or apply to the resonator manufacturer for evaluation.
Resonator
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
• Do not ground the capacitor to a ground pattern through which a high current flows.
• Do not fetch signals from the oscillator.
consumption, and is more prone to malfunction due to noise than the high-speed system clock
oscillator. Particular care is therefore required with the wiring method when the subsystem
clock is used.
Recommended Circuit
V
XT2
SS
CHAPTER 28 ELECTRICAL SPECIFICATIONS ((A1) GRADE PRODUCTS)
C4
Rd
XT2
C3
XT1
XT1
DD
DD
Oscillation frequency (f
= EV
= EV
DD
DD
Oscillation frequency
(f
XT1 input frequency
(f
XT1 input high-/low-level
width (t
Parameter
XT
XT
≤ 5.5 V, 2.7 V ≤ AV
≤ 5.5 V, 2.0 V ≤ AV
)
)
Note1
Note1
User’s Manual U16962EJ3V0UD
XTH
Parameter
, t
XTL
R
)
)
REF
REF
≤ V
≤ V
DD
DD
Conditions
, V
, V
Conditions
SS
SS
= EV
= EV
SS
SS
= AV
= AV
SS
SS
MIN.
MIN.
120
32
32
12
= 0 V)
= 0 V)
32.768
TYP.
TYP.
240
SS
MAX.
MAX.
38.5
15.6
490
.
35
Unit
kHz
Unit
kHz
kHz
µ
445
s