7.3
Port 2
7.3.1
Overview
Port 2 is an 8-bit input/output port with the pin configuration shown in figure 7.5. The pin
functions differ depending on the operating mode.
Port 2 has built-in, programmable MOS input pull-up transistors that can be used in modes 2 and
3.
Pins in port 2 can drive one TTL load and a 90-pF capacitive load. They can also drive LEDs and
darlington transistors.
Pin configuration
in mode 1
Pin configuration
in mode 2
(expanded mode
with on-chip ROM
disabled)
(expanded mode
with on-chip ROM
enabled)
Port 2 pins
P27/A15
P26/A14
P25/A13
P24/A12
P23/A11
P22/A10
P21/A9
A
A
A
A
A
A
15 (output)
14 (output)
13 (output)
12 (output)
11 (output)
10 (output)
A15 (output)/P27 (input)
A14 (output)/P26 (input)
A13 (output)/P25 (input)
A12 (output)/P24 (input)
A11 (output)/P23 (input)
A10 (output)/P22 (input)
A9 (output)/P21 (input)
A8 (output)/P20 (input)
Port 2
A9 (output)
A8 (output)
P20/A8
Pin configuration in mode 3
(single-chip mode)
P27 (input/output)
P26 (input/output)
P25 (input/output)
P24 (input/output)
P23 (input/output)
P22 (input/output)
P21 (input/output)
P20 (input/output)
Figure 7.5 Port 2 Pin Configuration
110
HITACHI [ HITACHI SEMICONDUCTOR ]
