38K0 Datasheet, PDF (12/133 Pages) Mitsubishi Electric Semiconductor – SINGLE-CHIP 8-BIT CMOS MICROCOMPUTER

38K0 Group
I/O PORTS
The I/O ports have direction registers which determine the input/
output direction of each individual pin. Each bit in a direction reg-
ister corresponds to one pin, and each pin can be set to be input
port or output port.
When “0” is written to the bit corresponding to a pin, that pin be-
comes an input pin. When “1” is written to that bit, that pin be-
comes an output pin.
If data is read from a pin set to output, the value of the port output
latch is read, not the value of the pin itself. Pins set to input are
floating. If a pin set to input is written to, only the port output latch
is written to and the pin remains floating.
Table 5 I/O ports functions
Pin
Name
P00–P07
Port P0
P10–P17
Port P1
P20–P27
Port P2
P30–P32
P33/ExINT
P34/ExCS
P35/ExWR
P36/ExRD
P37/ExA0
P40/RxD/
ExDREQ
P41/TxD/
ExDACK
P42/SCLK/
ExTC
P43/SRDY/
ExA1
P50/INT0
P52/INT1
Port P3
Port P4
Port P5
P51/CNTR0
P53–P57
P60–P63
Port P6
Input/Output
Input/output,
individual bits
I/O Format
CMOS compatible
input level
CMOS 3-state output
CMOS compatible
input level
CMOS 3-state output
(Power source is
VCCE)
CMOS compatible
input level
CMOS 3-state output
CMOS/TTL compat-
ible input level
CMOS 3-state output
(Power source is
VccE)
CMOS compatible
input level
CMOS 3-state output
Non-Port Function
Key-on wake up
A/D conversion input
External bus interface
funciton I/O
External bus interface
funciton output
External bus interface
funciton input
Serial I/O input
External bus interface
funciton output
Serial I/O output
External bus interface
funciton input
Serial I/O I/O
External bus interface
funciton input
Serial I/O output
External bus interface
funciton input
External interrupt input
Timer X function I/O
Related SFRs
Port P0 pull-up control
register
AD control register
EXB control register
EXB control register
EXB control register
Serial I/O control
register
EXB control register
Serial I/O control
register
EXB control register
Serial I/O control
register
EXB control register
Serial I/O control
register
EXB control register
Port P5 pull-up control
register
Interrupt edge selection
register
Timer X mode register
Diagram No.
(1)
(2)
(3)
(4)
(5)
(6)
(7)
(8)
(9)
(10)
(11)
(12)
(13)
(14)
Note: Make sure that the input level at each pin is either 0 V or VCC during execution of the STP instruction. When an input level is at an intermediate poten-
tial, a current will flow from VCC to VSS through the input-stage gate.
Rev.3.00 Oct 05, 2006 page 12 of 129
REJ03B0192-0300