xe1414c Xecom, Inc, xe1414c Datasheet - Page 3

• Manufacturer Part Number: xe1414c
• Description: Worldwide 14.4 Kbps Modem Module For Embedded Applications
• Manufacturer: Xecom, Inc

XE1414C PIN DESCRIPTIONS
27-28
31-35
XECOM
PIN NAME
4-8
10
11
12
13
14
15
16
18
20
21
22
29
30
36
37
1
2
3
9
RESET
L1, L2
RING
\DTR
GND
AMP
RXD
\CTS
TXD
\RTS
LCS
N/C
N/C
N/C
TIP
NC
AR
NC
NC
NC
\RI
OH
No Internal Connection
Auxiliary Data/Voice Relay, Active High Output, TTL/CMOS. The AR signal goes high when ever the mo-
dem is in the on-hook state. It can be connected to an external relay to switch control of the telephone line
between the modem and an auxiliary handset when.
Received Data, Output, TTL. Serial data output to the host. A logic "High" on RXD represents a "mark"
and a logic "Low" represents a "space".
No Internal Connection
Data Terminal Ready, Input, active Low, TTL. The "AT&D" command sets the function of \DTR. The de-
fault, AT&D2, requires the host to assert \DTR to permit a modem link. The modem drops the call in
progress if \DTR is revoked and will not connect until \DTR is reasserted.
Loop Current Sense, input, active High, TTL/CMOS. LCS provides an input to the modem from an ex-
ternal loop current sensor. The Loop Current Sensor may be required for some applications in which the
modem shares a telephone line with a telephone handset.
Clear to Send, Output, active Low, TTL/CMOS. \CTS provides the flow control output from the modem
when hardware flow control is selected. The modem revokes \CTS when the modem's input buffer is
full. The modem reasserts \CTS when the buffer can accept more data without a buffer overflow.
No Internal Connection
Transmit Data, Input, TTL. Serial data input from the host. A logic "High" represents a "mark" and a
Low represents a "space", TTL.
Request to Send, input, active Low, TTL. The XE1414C uses \RTS for hardware flow control. When
\RTS is revoked; hardware flow control is activated, and the modem will not place data on RXD.
No Internal Connection
Ring Indicator, Output, active Low, TTL. When low indicates the modem is receiving a ring signal.
Tip connection to the phone line (RJ11 pin 3) from the internal DAA. The XE1414C is not sensitive to
the battery voltage polarity across Tip and Ring.
Ring connection to the phone line (RJ11 pin 4) from the internal DAA.
Ground (0 volts)
Audio Output function is set by L & M commands and the value in register S22. This output can drive a
minimum load of 300 ohms.
L1 and L2 provide the control the performance of the loop current holding circuit. When a jumper is applied
between L1 and L2, the CTR21 current limiting circuit is active and DC loop current is limited to 60
milliamps. When no jumper is provided, a full 100 milliamps of loop current is supported.
No Internal Connection
Off-Hook, Output, active High. OH indicates the modem's hookswitch relay is closed. Hookswitch closure
connects the modem to the telephone line.
No Internal Connection
Hardware reset pin, Input, active High, TTL. A high on Pin 36 initiates a hardware reset. An external reset
is not required or recommended. The Reset pulse must be held a minimum of 100 milliseconds.
No Internal Connection
DESCRIPTION
(3)
XE1414C