Technical information
4
MITSUBISHI MICROCOMPUTERS
3820 Group
SINGLE-CHIP 8-BIT CMOS MICROCOMPUTER
Function
• Apply voltage of 2.5 V to 5.5 V to VCC, and 0 V to VSS.
(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 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 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
VSS
RESET
XIN
XOUT
VL1 – VL3
COM
0
– COM
3
SEG
0
– SEG
15
P00/
SEG
24
–
P07/
SEG
31
P10/
SEG
32
–
P17/
SEG
39
P20
–
P27
P30/
SEG
16
–
P37/
SEG
23
P40
P41/ φ
P42/INT0,
P43/INT1
P44/RXD,
P45/TXD,
P46/SCLK1,
P47/SRDY1
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
PIN DESCRIPTION