Xircom An Intel Company GEM3501 User Manual
Core Engine GSM/GPRS Modem Developer Guide Preliminary Draft: 7/6/2001
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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
5.2.2 Hardware Signals
5.2.2.1 “SLEEP” Signal
The SLEEP signal indicates whether or not the Core Engine RF section is active. When
the RF section is shutdown, the SLEEP signal will be Low. The SLEEP output is provided
if a host application wants to use it, but it is not necessary to use this pin. Usage would
depend on the host device and application. Some examples of when the SLEEP signal
may be useful are as follows:
the RF section is shutdown, the SLEEP signal will be Low. The SLEEP output is provided
if a host application wants to use it, but it is not necessary to use this pin. Usage would
depend on the host device and application. Some examples of when the SLEEP signal
may be useful are as follows:
!
Power down other host elements when the Core Engine radio is inactive: Monitoring
the SLEEP signal allows the host to detect when the radio is asleep so that other
elements of the host device may be powered down while there is no radio activity,
and so saving power.
the SLEEP signal allows the host to detect when the radio is asleep so that other
elements of the host device may be powered down while there is no radio activity,
and so saving power.
!
Avoid multiple elements transmitting simultaneously: If the host device incorporates
another transmitting device (such as Bluetooth or 802.11) then the host may monitor
the SLEEP signal to confirm the Core Engine is not active before transmitting on one
of the other devices - it may be desirable to limit the implementation only one
technology or device is active or transmitting at once.
another transmitting device (such as Bluetooth or 802.11) then the host may monitor
the SLEEP signal to confirm the Core Engine is not active before transmitting on one
of the other devices - it may be desirable to limit the implementation only one
technology or device is active or transmitting at once.
5.2.2.2 “PWR_DWN” Signal
The PWR_DWN signal triggers the software power down sequence (the same as the
AT+CPWROFF software command). The Core Engine will be released from the network
and the RF section will be shutdown. At this time the SLEEP signal will be Low. The
Core Engine will transition to “DORMANT” mode. The WAKE_UP signal or RESET_B
signal can be used to make the Core Engine re-activate and register on the network.
AT+CPWROFF software command). The Core Engine will be released from the network
and the RF section will be shutdown. At this time the SLEEP signal will be Low. The
Core Engine will transition to “DORMANT” mode. The WAKE_UP signal or RESET_B
signal can be used to make the Core Engine re-activate and register on the network.
5.2.2.3 “WAKE_UP” Signal
The WAKE_UP signal will transition the Core Engine to the “READY” mode from the “RF
DISABLED”, “SLEEP” or “DORMANT” modes. The WAKE_UP signal (active Low) must
be held active for at least 10 microseconds.
DISABLED”, “SLEEP” or “DORMANT” modes. The WAKE_UP signal (active Low) must
be held active for at least 10 microseconds.
5.2.2.4 “RESET_B” Signal
The RESET_B signal can be used to perform a complete restart the Core Engine, similar
to cycling power to the Core Engine. The RESET_B signal (active Low) must be held
active for at least 10 microseconds.
to cycling power to the Core Engine. The RESET_B signal (active Low) must be held
active for at least 10 microseconds.
5.2.3 Software Commands
5.2.3.1 AT+CPWROFF
The “AT+CPWROFF” command will perform a graceful shutdown and transition the Core
Engine to the “DORMANT” mode. No subsequent AT commands will recognized by the
Core Engine until it is reset, either by cycling power or by either a WAKE_UP or a
RESET_B hardware signal.
Engine to the “DORMANT” mode. No subsequent AT commands will recognized by the
Core Engine until it is reset, either by cycling power or by either a WAKE_UP or a
RESET_B hardware signal.
5.2.3.2 AT+CFUN
The “AT+CFUN” command can be used to instruct the Core Engine to enter the “RF
DISABLED”, “SLEEP” or “DORMANT” mode, or to return to the “READY” mode. Unlike
the AT+CPWROFF command, the AT+CFUN command does not disable the Core Engine
AT command interface.
DISABLED”, “SLEEP” or “DORMANT” mode, or to return to the “READY” mode. Unlike
the AT+CPWROFF command, the AT+CFUN command does not disable the Core Engine
AT command interface.