MITSUBISHI MICROCOMPUTERS
3822 Group
SINGLE-CHIP 8-BIT CMOS MICROCOMPUTER
PIN DESCRIPTION
Table 1 Pin description (1)
Pin
Name
Function
Function except a port function
VCC, VSS
Power source
•Apply voltage of power source to VCC, and 0 V to VSS. (For the limits of VCC, refer to “Recom-
mended operating conditions”).
VREF
AVSS
Analog refer-
ence voltage
•Reference voltage input pin for A-D converter.
Analog power
source
•GND input pin for A-D converter.
•Connect to VSS.
Reset input
Clock input
•Reset input pin for active “L”.
RESET
XIN
•Input and output pins for the main clock generating circuit.
•Feedback resistor is built in between XIN pin and XOUT pin.
•Connect a ceramic resonator or a quartz-crystal oscillator between the XIN and XOUT pins to set
the oscillation frequency.
XOUT
Clock output
•If an external clock is used, connect the clock source to the XIN pin and leave the XOUT pin open.
•This clock is used as the oscillating source of system clock.
•Input 0 ≤ VL1 ≤ VL2 ≤ VL3 ≤ VCC voltage.
LCD power
source
VL1–VL3
•Input 0 – VL3 voltage to LCD.
Common output
•LCD common output pins.
COM0–COM3
•COM2 and COM3 are not used at 1/2 duty ratio.
•COM3 is not used at 1/3 duty ratio.
SEG0–SEG11
Segment output
I/O port P0
•LCD segment output pins.
P00/SEG16–
P07/SEG23
•8-bit output port.
•LCD segment output pins
•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.
P10/SEG24–
P17/SEG31
I/O port P1
I/O port P2
•Pull-down control is enabled.
•Key input (key-on wake-up) interrupt
•8-bit I/O port.
P20 – P27
input pins
•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.
•4-bit input port.
•LCD segment output pins
P3
P3
4
/SEG12
/SEG15
–
Input port P3
7
•CMOS compatible input level.
•Pull-down control is enabled.
4
MITSUBISHI [ Mitsubishi Group ]
