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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
VCC
VSS
RESET
XIN
XOUT
VL1 – VL3
COM0 – COM3
SEG0 – SEG15
P00/SEG24 –
P07/SEG31
P10/SEG32 –
P17/SEG39
P20 – P27
P30/SEG16 –
P37/SEG23
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