UPD789304 Datasheet, PDF (39/64 Pages) NEC – 8-BIT SINGLE-CHIP MICROCONTROLLER

µPD789304, 789306, 789314, 789316
RC oscillation (µPD789314, 789316)
Resonator Recommended Circuit
Parameter
RC
resonator
CL1
CL2 _{Oscillation frequency}
(fCC)^{Note 1}
Oscillation stabilization
time^{Note 2}
External
clock
CL1
CL1
CL1 input frequency
CL2
(fCC)^{Note 1}
CL1 input high-/low-level
width (tXH, tXL)
CL2
OPEN
CL1 input frequency
(fCC)^{Note 1}
CL1 input high-/low-level
width (tXH, tXL)
Conditions
(TA = –40 to +85°C, VDD = 1.8 to 5.5 V)
MIN. TYP. MAX.
Unit
2.0
4.0
MHz
VDD = 2.7 to 5.5 V
32
128
1.0
µs
µs
4.0
MHz
100
500
ns
VDD = 2.7 to 5.5 V
1.0
VDD = 2.7 to 5.5 V
100
4.0
MHz
500
ns
Notes 1. Indicates only oscillator characteristics. Refer to AC Characteristics for instruction execution time.
2. Time required to stabilize oscillation after reset or STOP mode release.
Cautions 1. When using the main system 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 VSS.
• Do not ground the capacitor to a ground pattern through which a high current flows.
• Do not fetch signals from the oscillator.
2. When the main system clock is stopped and the device is operating on the subsystem
clock, wait until the oscillation stabilization time has been secured by the program before
switching back to the main system clock.
Data Sheet U14384EJ1V0DS
39