MITSUBISHI MICROCOMPUTERS
3820 Group
SINGLE-CHIP 8-BIT CMOS MICROCOMPUTER
PIN DESCRIPTION
Pin
V
CC
V
SS
RESET
X
IN
X
OUT
Reset input
Clock input
Clock output
• 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.
• LCD segment output pins
8-bit I/O port
CMOS compatible input level
CMOS 3-state output structure
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 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.
• 8-bit Input port
• CMOS compatible input level
• Pull-down control is enabled.
• 1-bit input pin
• CMOS compatible input level
•
•
•
•
7-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.
•
φ
clock output pin
• Interrupt input pins
• Serial I/O1 function pins
•
•
•
•
• Key input (key-on wake up) interrupt
input pins
•
•
•
•
• LCD segment pins
Name
Power source
Function
• Apply voltage of 2.5 V to 5.5 V to V
CC
, and 0 V to V
SS
.
(Extended operating temperature version : 3.0 V to 5.5 V)
Function except a port function
V
L1
– V
L3
COM
0
– COM
3
LCD power source
Common output
SEG
0
– SEG
15
P0
0
/SEG
24
–
P0
7
/SEG
31
Segment output
I/O port P0
P1
0
/SEG
32
–
P1
7
/SEG
39
I/O port P1
P2
0
– P2
7
I/O port P2
P3
0
/SEG
16
–
P3
7
/SEG
23
P4
0
P4
1
/
φ
P4
2
/INT
0
,
P4
3
/INT
1
P4
4
/R
X
D,
P4
5
/T
X
D,
P4
6
/S
CLK1,
P4
7
/S
RDY1
Input port P3
• LCD segment pins
Input port P4
I/O port P4
4
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