74
CHAPTER 3 PIN FUNCTIONS (
μ
PD78018F SUBSERIES)
3.2.6 P50-P57 (Port5)
These pins form an 8-bit I/O port, port 5, which also serves as an address bus.
These pins can directly drive LEDs.
Port 5 can be set in the following operation modes in 1-bit units.
(1) Port mode
In this mode, P50 through P57 constitute an 8-bit I/O port which can be set in the input or output mode in 1-
bit units by using the port mode register 5 (PM5). When used as an input port, an internal pull-up resistor
can be used if so specified by the pull-up resistor option register (PUO).
(2) Control mode
In this mode, P50 through P57 function as the high-order address bus pins (A8-A15) in the external memory
extension mode. The pins used as address bus pins are automatically disconnected from the internal pull-
up resistor.
3.2.7 P60-P67 (Port6)
These pins constitute an 8-bit I/O port, port 6, which can be also used to output control signals in the external
memory extension mode.
P60 through P63 can directly drive LEDs.
Port 6 can be set in the following operation modes in 1-bit units.
(1) Port mode
In this mode, P60 through P67 constitute an 8-bit I/O port, which can be set in the input or output mode in
1-bit units by using the port mode register 6 (PM6).
P60 through P63 are N-ch open drain pins. These pins of the mask ROM model can be connected to an internal
pull-up resistor by mask option.
When using P64 through P67 as input port pins, an internal pull-up resistor can be used if so specified by the
pull-up resistor option register (PUO).
(2) Control mode
In this mode, P60 through P67 functions as control signal output pins (RD, WR, WAIT, and ASTB) in the
external memory extension mode. The pins used as control signal output pins are automatically disconnected
from the internal pull-up resistor.
Caution If the external wait state is not used in the external memory extension mode, P66 can be used
as an I/O port pin.
3.2.8 AV
REF
This pin inputs a reference voltage to the A/D converter.
Connect this pin to V
SS
when the A/D converter is not used.
3.2.9 AV
DD
This is the analog power supply pin of the A/D converter.
Keep this pin at the same voltage as the V
DD
pin even when the A/D converter is not used.
3.2.10 AV
SS
This is the ground pin of the A/D converter.
Keep this pin at the same voltage as the V
SS
pin even when the A/D converter is not used.