1-5
3820 GROUP USER’S MANUAL
MITSUBISHI MICROCOMPUTERS
3820 Group
SINGLE-CHIP 8-BIT CMOS MICROCOMPUTER
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)
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.
Pin
V
CC
V
SS
RESET
X
IN
X
OUT
V
L1
– V
L3
COM
0
– COM
3
SEG
0
– SEG
15
P0
0
/
SEG
24
–
P0
7
/
SEG
31
P1
0
/
SEG
32
–
P1
7
/
SEG
39
P2
0
–
P2
7
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
Table 1. Pin description (1)
PIN DESCRIPTION
Name
Power source
Reset input
Clock input
Clock output
LCD power source
Common output
Segment output
I/O port P0
I/O port P1
I/O port P2
Input port P3
Input port P4
I/O port P4
Function except a port function
LCD segment pins
Key input (key-on wake up) interrupt
input pins
LCD segment pins
φ
clock output pin
Interrupt input pins
Serial I/O1 function pins