MITSUBISHI MICROCOMPUTERS
7477/7478 GROUP
SINGLE-CHIP 8-BIT CMOS MICROCOMPUTER
PIN DESCRIPTION
Input/
Output
Pin
Name
Functions
Apply voltage of 2.7 to 5.5V to VCC, and 0V to VSS.
VCC, VSS
Power source
AVSS
(Note 1)
Analog power
source
Ground level input pin for A-D converter.
Same voltage as VSS is applied.
RESET
Reset input
Input
To enter the reset state, the reset input pin must be kept at “L” for 2µs or more
(under normal VCC conditions).
XIN
Clock input
Input
These are I/O pins of internal clock generating circuit for main clock. To
control generating frequency, an external ceramic or a quartz crystal oscillator
is connected between the XIN and XOUT pins. If an external clock is used, the
clock source should be connected the XIN pin and the XOUT pin should be left
open. Feedback resistor is connected between XIN and XOUT.
XOUT
Clock output
Output
VREF
Reference voltage
input
Input
I/O
Reference voltage input pin for A-D converter.
P00 – P07
I/O port P0
Port P0 is an 8-bit I/O port. The output structure is CMOS output.
When this port is selected for input, pull-up transistor can be connected in
units of 1-bit and a key on wake up function is provided.
P10 – P17
I/O port P1
I/O
Port P1 is an 8-bit I/O port. The output structure is CMOS output.
When this port is selected for input, pull-up transistor can be connected in
units of 4-bit. P12 and P13 are in common with timer output pins T0 and T1.
P14, P15, P16 and P17 are in common with serial I/O pins RXD, TXD, SCLK
____
and SRDY, respectively.
P20 – P27
(Note 2)
Input port P2
Input port P3
Input
Input
Port P2 is an 8-bit input port.
This port is in common with analog input pins IN0 to IN7.
P30 – P33
Port P3 is a 4-bit input port. P30, P31 are in common with external interrupt
input pins INT0, INT1, and P32, P33 are in common with timer input pins
CNTR0, CNTR1.
P40 – P43
(Note 3)
I/O port P4
I/O
Port P4 is a 4-bit I/O port. The output structure is CMOS output, When this
port is selected for input, pull-up transistor can be connected in units of 4-bit.
P50 – P53
(Note 4)
Input port P5
Input
Port P5 is a 4-bit input port and pull-up transistor can be connected in units of
4-bit. P50, P51 are in common with input/output pins of clock for clock function
XCIN, XCOUT. When P50, P51 are used as XCIN, XCOUT, connect a ceramic or a
quartz crystal oscillator between XCIN and XCOUT. If an external clock input is
used, connect the clock input to the XCIN pin and open the XCOUT pin.
Feedback resistor is connected between XCIN and XCOUT pins.
Notes 1 : AVSS for M37478M4/M8/E8-XXXFP.
2 : Only P20–P23 (IN0–IN3) 4-bit for the 7477 group.
3 : Only P40 and P41 2-bit for the 7477 group.
4 : This port is not included in the 7477 group.
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MITSUBISHI [ Mitsubishi Group ]
