MITSUBISHI MICROCOMPUTERS
3827 Group
SINGLE-CHIP 8-BIT CMOS MICROCOMPUTER
PIN DESCRIPTION
Table 1 Pin description (1)
Pin
Name
Function
Function except a port function
VCC, VSS
VREF
Power source
•Apply voltage of 2.2 V to 5.5 V to VCC, and 0 V to VSS.
Analog refer-
ence voltage
•Reference voltage input pin for A-D converter and D-A converter.
AVSS
Analog power
source
•GND input pin for A-D converter and D-A 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.
•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.
LCD power
source
•Input 0 ≤ VL1 ≤ VL2 ≤ VL3 ≤ VCC voltage.
VL1–VL3
C1, C2
•Input 0 – VL3 voltage to LCD.
Charge-pump
capacitor pin
•External capacitor pins for a voltage multiplier (3 times) of LCD contorl.
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.
•LCD segment output pins.
SEG0–SEG17 Segment output
P00/SEG26–
P07/SEG33
I/O port P0
•8-bit output port.
•LCD segment output pins
•CMOS compatible input level.
•CMOS 3-state output structure.
•Pull-up control is enabled.
•I/O direction register allows each port to be individually
programmed as either input or output.
P10/SEG34– I/O port P1
P15/SEG39
•6-bit output port with same function as port P0.
•CMOS compatible input level.
•CMOS 3-state output structure.
•Pull-up control is enabled.
•I/O direction register allows each 6-bit pin to be pro-
grammed as either input or output.
P16, P17
•2-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.
P20 – P27
•8-bit I/O port with same function as port P0.
•CMOS compatible input level.
•Key input (key-on wake-up) interrupt
input pins
I/O port P2
•CMOS 3-state output structure.
•Pull-up control is enabled.
•LCD segment output pins
P3
P3
0
/SEG18
/SEG25
–
Output port P3
•8-bit output port with same function as port P0.
•CMOS 3-state output structure.
•Port output control is enabled.
7
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MITSUBISHI [ Mitsubishi Group ]
