UPD784026 Renesas Electronics Corporation., UPD784026 Datasheet - Page 120

• Manufacturer Part Number: UPD784026
• Description: 16/8-bit Single-chip Microcontrollers
• Manufacturer: Renesas Electronics Corporation.

4.4 CAUTIONS
4.4.1 When an External Clock Is Input
(1) If the STOP mode is used with external clock input, the EXTC bit of the oscillation stabilization time specification register
(2) When setting the EXTC bit of the OSTS to 1, be sure to input a clock in phase reverse to that of the clock input to the X1
(3) Even when inputting the external clock by clearing the EXTC bit of the oscillation stabilization time specification register
(4) When an external clock is input, this should be performed with a HCMOS device, or a device with the equivalent drive
(5) A signal should not be extracted from the X1 and X2 pins. If a signal is extracted, it should be extracted from point a in Figure
(6) The wiring connecting the X1 pin to the X2 pin via an inverter, in particular, should be made as short as possible.
80
The following cautions apply to the clock generator.
(OSTS) must be set (1). If the STOP mode is used when the EXTC bit is in the cleared (0) state, the PD784026 may be
damaged or suffer reduced reliability.
pin, to the X2 pin.
(OSTS) to 0, input a signal in phase reverse to that of the signal input to the X1 pin, to the X2 pin, whenever possible.
Otherwise, more malfunctioning may occur due to noise.
capability.
4-5.
Figure 4-5 Signal Extraction with External Clock Input
PD74HC04, etc.
CHAPTER 4 CLOCK GENERATOR
a
X1
X2
PD784026