NEC uPD78056Y - Manual (Page 67)

67
CHAPTER 3 PIN FUNCTION (
µ
PD78054 Subseries)
3.2.5 P40 to P47 (Port 4)
These are 8-bit input/output ports. Besides serving as input/output ports, they function as an address/data bus.
The test input flag (KRIF) can be set to 1 by detecting a falling edge.
The following operating mode can be specified in 8-bit units.
(1) Port mode
These ports function as 8-bit input/output ports. They can be specified in 8-bit units for input or output ports
by using the memory expansion mode register (MM). When they are used as input ports, on-chip pull-up
resistors can be used by defining the pull-up resistor option register L (PUOL).
(2) Control mode
These ports function 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.
3.2.6 P50 to P57 (Port 5)
These are 8-bit input/output ports. Besides serving as input/output ports, they function as an address bus.
Port 5 can drive LEDs directly.
The following operating modes can be specified in 1-bit units.
(1) Port mode
These ports function as 8-bit input/output ports. They can be specified in 1-bit units as input/output ports with
port mode register 5 (PM5). When they are used as input ports, on-chip pull-up resistors can be used by
defining the pull-up resistor option register L (PUOL).
(2) Control mode
These ports function 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.
3.2.7 P60 to P67 (Port 6)
These are 8-bit input/output ports. Besides serving as input/output ports, they are used for control in external
memory expansion mode. P60 to P63 can drive LEDs directly.
The following operating modes can be specified in 1-bit units.
(1) Port mode
These ports function as 8-bit input/output ports. They can be specified in 1-bit units as input or output ports
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 input ports, on-chip pull-up resistors can be used by defining the pull-up resistor
option register L (PUOL).
(2) Control mode
These ports function 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.