Ref; Cl1 And Cl2 ( Μ Pd754144 Only); X1 And X2 ( Μ Pd754244 Only); Reset - NEC PD754144 User Manual

4-bit single-chip microcontrollers
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2.2.8 AV
... input pin shared with port 6

REF

This is a reference voltage input pin. An analog reference voltage for the programmable threshold port is input.
2.2.9 CL1 and CL2 ( µ PD754144 only)
These pins are used to connect the RC oscillator resistor (R) and capacitor (C) of the system clock oscillator.
No external clock can be input.
2.2.10 X1 and X2 ( µ PD754244 only)
These pins connect a crystal/ceramic oscillator for system clock oscillation.
An external clock can also be input to these pins.
(a) Ceramic/crystal oscillation
Crystal resonator
or
ceramic resonator

2.2.11 RESET

This pin inputs an active-low reset signal.
The RESET signal is an asynchronous input signal and is asserted when a signal with a specific low-level width
is input to this pin regardless of the operating clock. The RESET signal takes precedence over all the other operations.
This pin can not only be used to initialize and start the CPU, but also to release the STOP and HALT modes.
The RESET pin is a Schmitt-triggered input pin.
This pin can be connected to an internal pull-up resistor by a mask option.
28
CHAPTER 2 PIN FUNCTIONS
RC oscillation
C
R
µ PD754244
X1
X2
V
SS
(4.194304 MHz TYP.)
User's Manual U10676EJ3V0UM
µ PD754144
CL1
CL2
V
SS
(b) External clock
ExternaI
clock
µ
PD754244
X1
X2

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Pd754244

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