Overview - Hitachi H8/3022 Hardware Manual

Port 7 Data Register (P7DR)
Bit
Initial value
Read/Write
Note: * Determined by pins P7
When port 7 is read, the pin levels are always read.
7.8 Port 8

7.8.1 Overview

Port 8 is a 2-bit input/output port that is also used for IRQ
pin configuration of port 8.
functions as input/output pin or as an IRQ
Pin P8
0
or IRQ input pins in modes 1, 3, 5, and 6, and as input/output pins or IRQ
1
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
156
7 6
P7 P7
7 6
— * — *
R R
to P7
7
and P8
1
Port 8 pins Modes 1, 3, 5, and 6
P8 /IRQ P8 (input)/IRQ
1 1 1
P8 /IRQ P8 (input/output)/IRQ
0 0 0
Figure 7-20 Port 8 Pin Configuration
5 4
P7 P7
5 4
— * — *
R R
.
0
and IRQ
1
input pin. Pins P8
0
have Schmitt-trigger inputs.
0
(input)
1
(input)
0
3 2
P7 P7
3 2
— * — *
R R
input. Figure 7-20 shows the
0
function as either input pins
1
input pins in mode 7.
1
Mode 7
P8 (input/output)/IRQ
1
P8 (input/output)/IRQ
0
1 0
P7 P7
1 0
— * — *
R R
(input)
1
(input)
0