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8.6
Port 5
8.6.1
Overview
Port 5 is a 4-bit input/output port with the pin configuration shown in figure 8.5. The pin functions
differ depending on the operating mode.
In modes 1 to 4 (expanded modes with on-chip ROM disabled), port 5 consists of address output
pins (A
to A
). In modes 5 (expanded modes with on-chip ROM enabled), settings in the port 5
19
16
data direction register (P5DDR) designate pins for address bus output (A
In mode 6, 7 (single-chip mode), port 5 is a generic input/output port.
Port 5 has software-programmable built-in pull-up transistors.
Pins in port 5 can drive one TTL load and a 90-pF capacitive load. They can also drive an LED or
a darlington transistor pair.
Port 5
Port 5
Modes 1 to 4
pins
P5 /A
A
(output)
3
19
19
P5 /A
A
(output)
2
18
18
P5 /A
A
(output)
1
17
17
P5 /A
A
(output)
0
16
16
Figure 8.5 Port 5 Pin Configuration
19
Mode 5
P5 (input)/A
(output)
3
19
P5 (input)/A
(output)
2
18
P5 (input)/A
(output)
1
17
P5 (input)/A
(output)
0
16
Rev. 4.00 Jan 26, 2006 page 285 of 938
Section 8 I/O Ports
to A
) or generic input.
16
Mode 6 and 7
P5 (input/output)
3
P5 (input/output)
2
P5 (input/output)
1
P5 (input/output)
0
REJ09B0276-0400
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