
1-5
SINGLE-CHIP 8-BIT CMOS MICROCOMPUTER
MITSUBISHI MICROCOMPUTERS
3822 Group
Function
 Apply voltage of 2.5 V to 5.5 V to VCC, and 0 V to VSS.
 Reference voltage input pin for A-D converter.
 GND input pin for A-D converter.
 Connect to VSS.
Reset input pin for active “L”
 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.
 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
 Input 0 – VL3 voltage to LCD
 LCD common output pins
 COM2 and COM3 are not used at 1/2 duty ratio.
 COM3 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 pin to be individually
programmed as either input or output.
 Pull-up control is enabled.
 4-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.
 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
Pin
VCC, VSS
VREF
AVSS
RESET
XIN
XOUT
VL1 – VL3
COM0 – COM3
SEG0 – SEG11
P00/SEG16 –
P07/SEG23
P10/SEG24 –
P17/SEG31
P20 – P27
P30/SEG12 –
P37/SEG15
P40
P41/
φ
P42/INT0,
P43/INT1
P44/RXD,
P45/TXD,
P46/SCLK,
P47/SRDY
Name
Power source
Analog reference
voltage
Analog 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
PIN DESCRIPTION