7.2
Port 1
7.2.1
Overview
Port 1 is an 8-bit input/output port with the pin configuration shown in figure 7.1. The pin
functions differ depending on the operating mode.
Port 1 has built-in, programmable MOS input pull-up transistors that can be used in modes 2 and
3.
Pins in port 1 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 1 pins
P17/A7
P16/A6
P15/A5
P14/A4
P13/A3
P12/A2
P11/A1
P10/A0
A7 (output)
A6 (output)
A5 (output)
A4 (output)
A3 (output)
A2 (output)
A1 (output)
A0 (output)
A7 (output)/P17 (input)
A6 (output)/P16 (input)
A5 (output)/P15 (input)
A4 (output)/P14 (input)
A3 (output)/P13 (input)
A2 (output)/P12 (input)
A1 (output)/P11 (input)
A0 (output)/P10 (input)
Port 1
Pin configuration in mode 3
(single-chip mode)
P17 (input/output)
P16 (input/output)
P15 (input/output)
P14 (input/output)
P13 (input/output)
P12 (input/output)
P11 (input/output)
P10 (input/output)
Figure 7.1 Port 1 Pin Configuration
104
HITACHI [ HITACHI SEMICONDUCTOR ]
