Rohm LAPIS SEMICONDUCTOR ML620Q503, User Manual

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ML620Q503/Q504 User's Manual
Chapter 16 Port XT
FEUL620Q504 16–1
16 Port XT
16.1 General Description
This LSI includes a 2-bit input port, port XT (PXT0, PXT1).
It can function as an external interrupt input, a low-speed crystal oscillation pin, or an external clock input pin.
When it is used as a low-speed crystal oscillation pin, the PXT1 pin functions as an output pin if the crystal
oscillation mode is selected with the XTM1 to XTM0 bits of the FCON2 register. For details of the FCON2
register, low-speed crystal oscillation, and external clock input, see Chapter 6, “Clock Generation Circuit”.
16.1.1 Features
•
Can be used as a high-impedance input.
•
Can be used as an external interrupt pin (EXII0 to EXII1), a low-speed crystal oscillation pin, or an
external clock input pin.
16.1.2 Configuration
Figure 16-1 shows the configuration of the port XT.
PXTD : Port XT data register
PXTDIR : Port XT direction register
Figure 16-1 Configuration of Port XT
16.1.3 List of Pins
Pin name I/O Primary function
PXT0/EXII0/XT0 I
Input port, External interrupt pin
Low-speed crystal oscillation pin
PXT1/EXII1/XT1/
LSCLKI
I/O
Input port, External interrupt pin
Low-speed crystal oscillation pin,
External low-speed clock input pin
Data bus
PXT0, PXT1
Low-speed
oscillator
circuit
V
DD
V
SS
2
XTCLK(32.768kHz)
2
STOP mode
1
PXTD
ENXT (Enable oscillation)
2
2
FCON2
(XTM1,XTM0)
EXII0 to EXII1
2
PXTDIR