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CHAPTER 4 PIN FUNCTION (
μ
PD780058Y Subseries)
4.2.5 P40 to P47 (Port 4)
This is an 8-bit input/output port. Besides serving as an input/output port, it functions as an address/data bus.
The test input flag (KRIF) can be set to 1 by detecting a falling edge.
The following operating modes can be specified in 8-bit units.
(1) Port mode
This port functions as an 8-bit input/output port. They can be specified in 8-bit units for an input or output
port by using the memory expansion mode register (MM). When it is used as an input port, on-chip pull-up
resistors can be used by defining the pull-up resistor option register L (PUOL).
(2) Control mode
This port functions as low-order address/data bus pins (AD0 to AD7) in external memory expansion mode.
When pins are used as an address/data bus, the on-chip pull-up resistor is automatically disabled.
4.2.6 P50 to P57 (Port 5)
This is an 8-bit input/output port. Besides serving as an input/output port, it functions as an address bus.
Port 5 can drive LEDs directly.
The following operating modes can be specified bit-wise.
(1) Port mode
This port functions as an 8-bit input/output port. It can be specified bit-wise as an input/output port with port
mode register 5 (PM5). When it is used as an input port, on-chip pull-up resistors can be used by defining
the pull-up resistor option register L (PUOL).
(2) Control mode
This port functions as high-order address bus pins (A8 to A15) in external memory expansion mode. When
pins are used as an address bus, the on-chip pull-up resistor is automatically disabled.
4.2.7 P60 to P67 (Port 6)
This is an 8-bit input/output port. Besides serving as an input/output port, it is used for control in external memory
expansion mode. P60 to P63 can be driven LEDs directly.
The following operating modes can be specified bit-wise.
(1) Port mode
This port functions as an 8-bit input/output port. It can be specified bit-wise as an input or output port with
port mode register 6 (PM6).
P60 to P63 are N-ch open drain outputs. Mask ROM version can contain pull-up resistors with the mask option.
When P64 to P67 are used as an input port, on-chip pull-up resistor can be used by defining the pull-up resistor
option register L (PUOL).
(2) Control mode
This port functions as control signal output pins (RD, WR, WAIT, ASTB) in external memory expansion mode.
When a pin is used as a control signal output, the on-chip pull-up resistor is automatically disabled.
Caution When external wait is not used in external memory expansion mode, P66 can be used as an
input/output port.