P30 To P37 (Port 3); P40 To P47 (Port 4); P50 To P57 (Port 5); P64 To P67 (Port 6) - NEC mPD780065 Series Preliminary User's Manual

2.2.3 P30 to P37 (Port 3)

This is an 8-bit input/output port. These pins can be specified in 1-bit units as input or output ports with port mode
register 3 (PM3). On-chip pull-up resistors can be specified by defining pull-up resistor option register 3 (PU3).

2.2.4 P40 to P47 (Port 4)

This is an 8-bit input/output port. Besides serving as input/output ports, these pins function as an address/data
bus.
The following operating mode can be specified in 1-bit units.
(1) Port mode
These pins function as an 8-bit input/output port. They can be specified in 1-bit units as input or output ports
with port mode register 4 (PM4). On-chip pull-up resistors can be specified by defining pull-up resistor option
register 4 (PU4).
(2) Control mode
These pins function as low-order address/data bus pins (AD0 to AD7) in external memory expansion mode.

2.2.5 P50 to P57 (Port 5)

This is an 8-bit input/output port. Besides serving as input/output ports, these pins function as an address bus.
The following operating modes can be specified in 1-bit units.
(1) Port mode
These pins function as an 8-bit input/output port. They can be specified in 1-bit units as input/output ports with
port mode register 5 (PM5). On-chip pull-up resistors can be specified by defining pull-up resistor option register
5 (PU5).
(2) Control mode
These pins function as high-order address bus pins (A8 to A15) in external memory expansion mode.

2.2.6 P64 to P67 (Port 6)

This is an 4-bit input/output port. Besides serving as input/output ports, these pins are used for control in external
memory expansion mode.
The following operating modes can be specified in 1-bit units.
(1) Port mode
These pins function as a 4-bit input/output port. They can be specified in 1-bit units as input or output ports with
port mode register 6 (PM6). On-chip pull-up resistors can be specified by defining pull-up resistor option register
6 (PU6).
(2) Control mode
These pins function as control signal output pins (RD, WR, WAIT, ASTB) in external memory expansion mode.
Caution When external wait is not used in external memory expansion mode, P66 can be used as an
input/output port.
CHAPTER 2 PIN FUNCTION
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