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Table 7.7
Input Pull-Up Transistor States (Port 4)
Mode
1 to 5
8-bit bus mode
16-bit bus mode
6 and 7
Legend:
Off
: The input pull-up transistor is always off.
On/off : The input pull-up transistor is on if P4PCR = 1 and P4DDR = 0. Otherwise, it is off.
7.6
Port 5
7.6.1
Overview
Port 5 is a 4-bit input/output port which also has an address output function. It's pin configuration
is shown in figure 7.5. 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 mode 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 modes 6 and 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
Hardware
Reset
Standby Mode
Off
Off
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 7.5 Port 5 Pin Configuration
Software
Standby Mode
On/off
Off
On/off
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
Other Modes
On/off
Off
On/off
to A
) or generic input.
16
Modes 6 and 7
P5 (input/output)
3
P5 (input/output)
2
P5 (input/output)
1
P5 (input/output)
0
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