UPD78F0138 NEC, UPD78F0138 Datasheet - Page 470

• Manufacturer Part Number: UPD78F0138
• Description: (UPD78xxxx) 8-Bit Single-Chip Microcontrollers
• Manufacturer: NEC

X1 Oscillator Characteristics
(T
Notes 1.
Cautions 1. When using the X1 oscillator, wire as follows in the area enclosed by the broken lines in the
470
Ceramic
resonator
Crystal
resonator
External
clock
Resonator Recommended Circuit
A
= −40 to +85°C, 2.7 V ≤ V
Note 3
2.
3.
2. Since the CPU is started by the Ring-OSC after reset, check the oscillation stabilization time of
CHAPTER 29 ELECTRICAL SPECIFICATIONS (STANDARD PRODUCTS, (A) GRADE PRODUCTS)
Indicates only oscillator characteristics. Refer to AC Characteristics for instruction execution time.
When the REGC pin is connected to V
Connect the REGC pin directly to V
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.
the X1 input clock using the oscillation stabilization time status register (OSTC). 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.
V
V
SS
SS
X1
C1
C1
X1
X1
C2
C2
X2
X2
X2
DD
= EV
Oscillation
frequency (f
Oscillation
frequency (f
X1 input
frequency (f
X1 input high-
/low-level width
(t
XPH
Parameter
DD
, t
XPL
≤ 5.5 V, 2.7 V ≤ AV
)
XP
XP
XP
User’s Manual U16228EJ2V0UD
)
)
)
Note 1
Note 1
Note 1
DD
.
SS
When a capacitor
is connected to
the REGC pin
When the REGC
pin is directly
connected to V
When a capacitor
is connected to
the REGC pin
When the REGC
pin is directly
connected to V
4.0 V ≤ V
3.3 V ≤ V
2.7 V ≤ V
4.0 V ≤ V
3.3 V ≤ V
2.7 V ≤ V
via a capacitor (1
REF
DD
DD
DD
DD
DD
DD
≤ 5.5 V
< 4.0 V
< 3.3 V
≤ 5.5 V
< 4.0 V
< 3.3 V
≤ V
Note 2
Note 2
Conditions
DD
DD
DD
, V
4.0 V ≤ V
4.0 V ≤ V
3.3 V ≤ V
2.7 V ≤ V
4.0 V ≤ V
4.0 V ≤ V
3.3 V ≤ V
2.7 V ≤ V
µ
SS
F: recommended).
= EV
DD
DD
DD
DD
DD
DD
DD
DD
SS
≤ 5.5 V
≤ 5.5 V
< 4.0 V
< 3.3 V
≤ 5.5 V
≤ 5.5 V
< 4.0 V
< 3.3 V
= AV
SS
= 0 V)
MIN.
2.0
2.0
2.0
2.0
2.0
2.0
2.0
2.0
2.0
2.0
2.0
46
56
96
TYP.
SS
MAX.
8.38
8.38
8.38
8.38
8.38
500
500
500
.
5.0
5.0
5.0
10
10
10
MHz
MHz
MHz
MHz
MHz
Unit
ns