XECOM (3) XE1414A
PIN NAME DESCRIPTION
3 RXD Serial data output to the DTE (i.e. external UART). A logic "high" represents a
"mark" and a logic "low" represents a "space", TTL.
9 \DTR Data Terminal Ready, input, active Low, TTL. The function of this pin is set by
the &D command. Normally the modem ignores DTR.
11 \CTS Clear to Send, output, active Low, TTL/CMOS. This pin regulates the flow of
data from the DTE during hardware flow control.
13 TXD Serial data input from the DTE (i.e. external UART). A logic "high" represents a
"mark" and a low represents a"space", TTL.
14 \RTS Request to Send, input, active Low, TTL. This signal regulates the flow of data
from the modem during hardware flow control.
16 \RI Ring Indicator, output, active Low, TTL. When low indicates the modem is
receiving a ring signal.
19 TIP Tip connection to the phone line(RJ11 pin3) from the internal DAA.
20 RING Ring connection to the phone line(RJ11 pin4) from the internal DAA. Caution:
21 GND Ground (0 volts)
22 AMP Audio output function is determined by L & M commands and the value in
register S22. This output can drive a 300 ohm load.
30 OH Oh is an active low output from the modem. Oh goes high when the modem is
"off-hook." This signal can be used to drive and external relay to switch line
usage between the modem and a handset.
36 RESET Hardware reset pin, active High, TTL. Use of an external reset is not
recommended. When not used Reset should be left open. Any signal applied to
Pin 36 must remain high for a minimum of 100 milliseconds.
38 \DCD Data Carrier Detect, output, active Low, TTL/CMOS. Function is set by the &C
command and the value in register S21.
39 \DSR Data Set Ready, output, active Low, TTL/CMOS. Function is set by the &S
command and the value in register S21.
40 Vcc +5 Volt power
XE1414A Pin Descriptions