Datasheet

V850ES/JG3-H, V850ES/JH3-H CHAPTER 33 ELECTRICAL SPECIFICATIONS
R01UH0042EJ0500 Rev.5.00 Page 1412 of 1513
Aug 12, 2011
33.4 Oscillator Characteristics
33.4.1 Main clock oscillator characteristics
(T
A = −40 to +85°C, VDD = EVDD = UVDD = AVREF0 = AVREF1, VSS = AVSS = 0 V, CL = 50 pF)
Resonator Circuit Example Parameter Conditions MIN. TYP. MAX. Unit
Oscillation frequency
(f
X)
Note 1
3 6 MHz
After reset is released 216/fX s
After STOP mode is
released
Note 3 ms
Ceramic
resonator/
crystal
resonator
X2X1
Oscillation stabilization
time
Note 2
After IDLE2 mode is
released
Note 3
μ s
Notes 1. The oscillation frequency shown above indicates only oscillator characteristics. Use the V850ES/JG3-H and
V850ES/JH3-H so that the internal operation conditions do not exceed the ratings shown in AC
Characteristics and DC Characteristics.
2. Time required from start of oscillation until the resonator stabilizes.
3. The value varies depending on the setting of the OSTS register.
Cautions 1. When using the USB controller, be sure to use a ceramic resonator or crystal resonator with an
accuracy of 6 MHz ±500 ppm or less when using the internal clock as the USB clock.
When using the external clock input by the UCLK pin, be sure to supply a clock with an accuracy of
48 MHz ±500 ppm or less.
If the USB clock accuracy drops, the transmission/reception data cannot satisfy the USB
specification.
2. When using the main clock oscillator, wire as follows in the area enclosed by the broken lines in the
above figure 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.
3. 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.