P30 To P33 (Port 3); P40 To P47 (Port 4); P50 To P57 (Port 5) - NEC 78K0 User Manual

2.2.4

P30 to P33 (port 3)

P30 to P33 function as a 4-bit I/O port. These pins also function as pins for external interrupt request input and
timer I/O.
The following operation modes can be specified in 1-bit units.
(1) Port mode
P30 to P33 function as a 4-bit I/O port. P30 to P33 can be set to input or output in 1-bit units using port mode
register 3 (PM3). Use of an on-chip pull-up resistor can be specified by pull-up resistor option register 3 (PU3).
(2) Control mode
P30 to P33 function as external interrupt request input pins and timer I/O pins.
(a) INTP1 to INTP4
These are the external interrupt request input pins for which the valid edge (rising edge, falling edge, or both
rising and falling edges) can be specified.
(b) TI51
This is an external count clock input pin to 8-bit timer/event counter 51.
(c) TO51
This is a timer output pin.
2.2.5

P40 to P47 (port 4)

P40 to P47 function as an 8-bit I/O port. These pins also function as address/data bus pins.
The following operation modes can be specified.
(1) Port mode
P40 to P47 function as an 8-bit I/O port. P40 to P47 can be set to input or output in 1-bit units using port mode
register 4 (PM4). Use of an on-chip pull-up resistor can be specified by pull-up resistor option register 4 (PU4).
(2) Control mode
P40 to P47 function as the pins for the lower address/data bus (AD0 to AD7) in external memory expansion
mode.
Caution The external bus interface function cannot be used in (A1) grade products and (A2) grade
products.
2.2.6

P50 to P57 (port 5)

P50 to P57 function as an 8-bit I/O port. These pins also function as address bus pins.
The following operation modes can be specified.
(1) Port mode
P50 to P57 function as an 8-bit I/O port. P50 to P57 can be set to input or output in 1-bit units using port mode
register 5 (PM5). Use of an on-chip pull-up resistor can be specified by pull-up resistor option register 5 (PU5).
(2) Control mode
P50 to P57 function as the pins for the higher address bus (A8 to A15) in external memory expansion mode.
Caution The external bus interface function cannot be used in (A1) grade products and (A2) grade
products.
CHAPTER 2 PIN FUNCTIONS
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User's Manual U15947EJ2V0UD
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