Pin Number

Signal Name

Direction

Description

#1

MD*

Input

Mode selection pin

#2

RST

Input

Reset, active high

#3

P3

DTR*

Input/output

Output

General-purpose input/output line

Data terminal ready output

#4

P2

DSR*

Input/output

Input

General-purpose input/output line

Data set ready input

#5

L3

SG*

Output

Output

LED output 3

Green status LED control line

#6

L4

SR*

Output

Output

LED output 4

Red status LED control line

#7

VCC

Positive power input, 5V nominal, +/- 5%, app. 220mA

#8

GND

Ground

#9

RX

Input

Serial receive line

#10

TX

Output

Serial transmit line

#11

P4

CTS/SEL*

Input/output

Input

General-purpose input/output line

Clear to send input; full-/half-duplex selection input

#12

P5

RTS/DIR*

Input/output

Output

General-purpose input/output line

Request to send output (full-duplex mode); data direction control output (half-duplex mode)

Pin Number

Signal Name

#1

RX+

#2

RX-

#3

AVCC

#4

---

#5

---

#6

GND

#7

TX+

#8

TX-