Chapter 8 Parallel Ports; Outline - Fujitsu F2MC-16LX MB90580 Series Hardware Manual

Chapter 8:
Parallel Ports

8.1 Outline

In MB90580 series, there are 10 parallel ports which are as follows:
• Port 0 (8 CMOS I/O pins)
• Port 1 (8 CMOS I/O pins)
• Port 2 (8 CMOS I/O pins)
• Port 3 (8 CMOS I/O pins)
• Port 4 (8 CMOS I/O pins with open-drain control)
• Port 5 (8 CMOS I/O pins)
• Port 6 (6 CMOS I/O pins)
• Port 7 (4 CMOS I/O pins)
• Port 8 (8 CMOS I/O pins)
• Port 9 (8 CMOS I/O pins)
• Port A (3 CMOS I/O pins)
Each pin of the ports can be specified as input or output using the direction register if the corresponding
peripheral does not use the pin. When a pin is specified as input, the value of the pin level is read from a
data register. When a pin is specified as output, the data register latch value is read from the data register.
The above also applies to a read operation for a read-modify-write instruction.
When a data register is read while the corresponding port is used as a control output, control output value
is read from the data register regardless of the direction register value.
When an input pin is changed into an output pin, care must be taken to use a read-modify-write instruction
(such as a bit set instruction) to set output data in the data register beforehand. In this case, the data input
from the pin is read instead of the data register latch value.