MITSUBISHI MICROCOMPUTERS
3822 Group
SINGLE-CHIP 8-BIT CMOS MICROCOMPUTER
PIN DESCRIPTION
Table 1 Pin description (1)
Pin
V
CC
, V
SS
V
REF
AV
SS
Name
Power source
Analog refer-
ence voltage
Analog power
source
Reset input
Clock input
Clock output
Function
Function except a port function
•Apply voltage of power source to V
CC
, and 0 V to V
SS
. (For the limits of V
CC
, refer to “Recom-
mended operating conditions”).
•Reference voltage input pin for A-D converter.
•GND input pin for A-D converter.
•Connect to V
SS
.
•Reset input pin for active “L”.
•Input and output pins for the main clock generating circuit.
•Feedback resistor is built in between X
IN
pin and X
OUT
pin.
•Connect a ceramic resonator or a quartz-crystal oscillator between the X
IN
and X
OUT
pins to set
the oscillation frequency.
•If an external clock is used, connect the clock source to the X
IN
pin and leave the X
OUT
pin open.
•This clock is used as the oscillating source of system clock.
•Input 0
≤
V
L1
≤
V
L2
≤
V
L3
≤
V
CC
voltage.
•Input 0 – V
L3
voltage to LCD.
•LCD common output pins.
•COM
2
and COM
3
are not used at 1/2 duty ratio.
•COM
3
is not used at 1/3 duty ratio.
RESET
X
IN
X
OUT
V
L1
–V
L3
COM
0
–COM
3
LCD power
source
Common output
SEG
0
–SEG
11
P0
0
/SEG
16
–
P0
7
/SEG
23
Segment output
I/O port P0
•LCD segment output pins.
•8-bit output port.
•CMOS compatible input level.
•CMOS 3-state output structure.
•LCD segment output pins
P1
0
/SEG
24
–
P1
7
/SEG
31
P2
0
– P2
7
I/O port P1
•I/O direction register allows each port to be individually
programmed as either input or output.
•Pull-down control is enabled.
•8-bit I/O port.
•CMOS compatible input level.
•CMOS 3-state output structure.
•I/O direction register allows each pin to be individually
programmed as either input or output.
•Pull-up control is enabled.
•Key input (key-on wake-up) interrupt
input pins
I/O port P2
P3
4
/SEG
12
–
P3
7
/SEG
15
Input port P3
•4-bit input port.
•CMOS compatible input level.
•Pull-down control is enabled.
•LCD segment output pins
4
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