XStream
‐
PKG
‐
T™
Telephone
RF
Modem
–
Product
Manual
v5.x00
[2006.02.24]
2.1.4.
Sleep Mode
Sleep Modes are not supported by the XStream-PKG-T Telephone RF Modem; however, Sleep
Modes can be implemented on remote modems connected to the telephone RF modem host.
Sleep Modes enable the XStream Modem to operate at minimal power consumption when not in
use. Three Sleep Mode options are available:
•
Pin Sleep (Host Controlled)
•
Serial Port Sleep (Wake on Serial Port activity)
•
Cyclic Sleep (Wake on RF activity)
For the modem to transition into Sleep Mode, the modem must have a non-zero SM (Sleep Mode)
Parameter and one of the following must occur:
1. The modem is idle (no data transmission or reception) for a user-defined period of time
[Refer to ST (Time before Sleep) Command].
2. SLEEP pin is asserted (only for Pin Sleep option).
In Sleep Mode, the modem will not transmit or receive data until the modem first transitions to
Idle Mode. All Sleep Modes are enabled and disabled using SM Command. Transitions into and
out of Sleep Modes are triggered by various mechanisms as shown in the table below.
For more information about Sleep Modes, refer to the individual commands listed in “Related
Commands” column of the table. SM Command is the best starting point for implementing sleep
mode configurations.
Pin Sleep (SM = 1)
Pin Sleep requires the least amount of power. In order to achieve this state, Pin 2 (SLEEP) must
be asserted (high). The module remains in Pin Sleep until the Sleep pin is de-asserted.
After enabling Pin Sleep, DI3 controls whether the XStream Module is active or in Sleep Mode.
When DI3 is de-asserted (low), the module is fully operational. When DI3 is asserted (high), the
module transitions to Sleep Mode and remains in its lowest power-consuming state until the
Sleep pin is de-asserted. DI3 is only active if the module is setup to operate in this mode;
otherwise the pin is ignored.
Once in Pin Sleep Mode, DO2 (pin 1,
) is de-asserted (high), indicating that data should not
be sent to the module. Pin 8 (PWR) is also de-asserted (low) when the module is in Pin Sleep
Mode.
Note: The module will complete a transmission or reception before activating Pin Sleep.
Serial Port Sleep (SM = 2)
Serial Port Sleep is a Sleep Mode in which the XStream Module runs in a low power state until
serial data is detected on the DI pin.
When Serial Port Sleep is enabled, the module goes into Sleep Mode after a user-defined period
of inactivity (no transmitting or receiving of data). This period of time is determined by ST (Time
before Sleep) Command. Once a character is received through the DI pin, the module returns to
Idle Mode and is fully operational.
Cyclic Sleep (SM = 3-8)
Cyclic Sleep is the Sleep Mode in which the XStream Module enters into a low-power state and
awakens periodically to determine if any transmissions are being sent.
When Cyclic Sleep settings are enabled, the XStream Module goes into Sleep Mode after a user-
defined period of inactivity (no transmission or reception on the RF channel). The user-defined
period is determined by ST (Time before Sleep) Command.
While the module is in Cyclic Sleep Mode, DO2 (
) is de-asserted (high) to indicate that data
should not be sent to the module during this time. When the module awakens to listen for data,
DO2 is asserted and any data received on the DI Pin is transmitted. PWR is also de-asserted
(low) when the module is in Cyclic Sleep Mode.
©
2006
MaxStream,
Inc.,
Confidential
and
Proprietary
12
