Oscillation Circuit; Main System Clock Oscillation Circuit Characteristics - NEC V850ES/DJ2 User Manual

9.4 Oscillation Circuit

9.4.1 Main System Clock Oscillation Circuit Characteristics

(V =EV =BV =MTV
DD DD DD
V =EV =BV =MTV
SS SS SS
T =-40 to +85°C)
A
Resonator Recommended circuit
X1
Crystal/
Ceramic
resonator
a) Time required from when V
stabilizes.
b) Stabilization time for Flash macro. Setting by OSTS resistor.
c) Depend on the setting of the oscillation stabilization time select resistor (OSTS).
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 capaci-
tance.
• 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 cur-
rent flows.
• Do not fetch signals from the oscillator.
1. 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.
Chapter 9 Electrical Specification
=SMV =AV
DD DD REF0
=SMV =AV =0 V,
SS SS SS
Parameter
Oscillation fre-
quency
X2
Oscillation stabili-
a
zation time
reaches oscillation voltage range (MIN.: 4.0 V) to when the crystal resonator
DD
.
SS
Preliminary User's Manual U17763EE1V1UD00
=4.0 to 5.5 V,
Conditions
After reset is released
After STOP mode is
released
After IDLE2 mode is
released
MIN. TYP. MAX.
4 5
16
2 /f
X
b
c
0.5
b
c
350
Unit
MHz
s
ms
µs
133