HD643303x Hitachi, HD643303x Datasheet - Page 161

• Manufacturer Part Number: HD643303x
• Description: Hitachi Microcomputer
• Manufacturer: Hitachi

7.8 Port 8
7.8.1 Overview
Port 8 is a 4-bit input/output port that is also used for IRQ
pin configuration of port 8.
Pin P8
input pins or IRQ
pins in modes 2 and 3.
Pins in port 8 can drive one TTL load and a 90-pF capacitive load. They can also drive a darlington
transistor pair. Pins P8
Port 8
0
functions as input/output pin or as an IRQ
3
to IRQ
Port 8 pins
P8
P8
P8
P8
2
to P8
3
2
1
0
/IRQ
/IRQ
/IRQ
/IRQ
1
input pins in mode 1, and as input/output pins or IRQ
0
Figure 7-17 Port 8 Pin Configuration
3
2
1
0
have Schmitt-trigger inputs.
Mode 1
P8
P8
P8
P8
3
2
1
0
(input)/IRQ
(input)/IRQ
(input)/IRQ
(input/output)/IRQ
146
0
3
2
1
input pin. Pins P8
(input)
(input)
(input)
3
0
to IRQ
(input)
0
input. Figure 7-17 shows the
Modes 2 and 3
P8
P8
P8
P8
3
to P8
3
2
1
0
(input/output)/IRQ
(input/output)/IRQ
(input/output)/IRQ
(input/output)/IRQ
1
function as either
3
to IRQ
1
3
2
1
0
input
(input)
(input)
(input)
(input)