Xircom An Intel Company GEM3501 User Manual
Core Engine GSM/GPRS Modem Developer Guide Preliminary Draft: 7/6/2001
19
Part Number: 07100026, Revision: 002
Confidential
© 2001 Xircom, Inc., an Intel company All rights reserved.
All trademarks and copyrights are the property of Xircom, Inc., an Intel company
All trademarks and copyrights are the property of Xircom, Inc., an Intel company
Pin
Number
Signal
Name
Direction
Functionality
2
RX0_DS
To CPE
Receive data 0. DCE Output signal. Main serial interface
transmit data signal. During idle or reset, signal will be a logic
1. Connects to a DTE, RX, receive data pin.
3
TX0_DS
From CPE
Transmit data 0. DCE Input signal. Active low. Main serial
interface receive data signal. During idle or reset, signal will
be a logic 1. Connects to a DTE, TX, transmit data pin.
7
RTS0_DS
From CPE
Request-To-Send 0. DCE Input signal. Active low. Main serial
interface request to send signal. Connects to a DTE, RTS,
Request-To-Send pin.
8
CTS0_DS
To CPE
Clear-To-Send 0. DCE Output signal. Active low. Main serial
interface clear to send signal. Connects to a DTE, CTS, Clear
to send pin.
Table 4: Carrier Board Secondary Serial Connector Pin Out
NOTE: The maximum length for the Secondary Serial cable is 25 feet.
4.8 Primary Audio Interface [P1]
The primary audio interface (connector P1 on the carrier board) uses an RJ-9 connector
and provides differential microphone input and speaker output.
and provides differential microphone input and speaker output.
Pin
Number
Signal
Name
Direction
Functionality
1
MIC0N
From CPE
Microphone Negative. Negative input pin from an electret-
type microphone. Nominal microphone differential voltage
should be 2.0 volts. Impedance not less than 900 ohms.
Leave signal disconnected if function is not used.
2
SPK0N
To CPE
Speaker Negative. Negative output pin. Low side of a
push-pull amplifier. Speaker impedance 15
ohms,
minimum. Speaker capacitance of 700
pF, maximum.
Driver voltage is 3.7V peak-to-peak. Leave signal
disconnected if function is not used.
3
SPK0P
To CPE
Speaker Positive. Positive output pin. High side of a push-
pull amplifier. Speaker impedance 15 ohms, minimum.
Speaker capacitance of 700 pF, maximum. Driver voltage
is 3.7V peak-to-peak. Leave signal disconnected if function
is not used.
4
MIC0P
From CPE
Microphone Positive. Positive input pin from an electret-
type microphone. Nominal microphone differential voltage
should be 2.0 volts. Impedance not less than 900 ohms.
Leave signal disconnected if function is not used.
Table 5: Carrier Board Primary Audio Port Connector Pin Out