Fujitsu F2MC-8L MB89620 Series Hardware Manual page 127

4.5 Port 4
4.5.1 Port 4 Register (PDR4)
This section describes the port 4 register.
n Port 4 Register Functions
Port 4 data register (PDR4)
The PDR4 register holds the pin states.
Notes: • When using peripherals that have output pins, enabling a peripheral's output enable bit, for a
Table 4.5.1 lists the functions of the port 4 register.
Table 4.5.1 Port 4 Register Function
Register
Port 4 data register
(PDR4)
R/W : Readable and writable
* : Pins with a pull-up resistor (optional) go to the pull-up state.
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CHAPTER 4 I/O PORTS
particular pin, sets that pin as a peripheral output pin.
When using peripherals that have input pins, set the PDR4-register bits corresponding
•
to the periphral input pins to "1" to turn the output transistor "OFF".
Data
Pin state is the "L"
0
level.
Pin state is the "H"
1
level.
Read Write
Outputs an "L" level to
the pin.
(Sets "0" to the output
latch and turns the
output transistor "ON".)
Sets the pin to the high-
impedance state.*
(Sets "1" to the output
latch and turns the
output transistor "OFF".)
Read/
Address Initial value
Write
R/W 000E 11111111
H
MB89620 series
B