LISA-U2 series - System Integration Manual
UBX-13001118 - R19
Early Production Information
System description
Page 62 of 175
AT+UPSV HW flow control
RTS line
DTR line
Communication during idle-mode and wake up
2
Enabled (AT&K3)
ON or OFF
ON or OFF
Not Applicable: HW flow control cannot be enabled with AT+UPSV=2.
2
Disabled (AT&K0)
ON
ON or OFF
Data sent by the DTE is correctly received by the module.
Data sent by the module is correctly received by the DTE if it is ready to receive
data, otherwise data is lost.
2
Disabled (AT&K0)
OFF
ON or OFF
Data sent by the DTE is lost by LISA-U2 modules.
The first character sent by the DTE is lost by LISA-U2 modules, but after
~20 ms the UART and the module are waked up: recognition of subsequent
characters is guaranteed after the complete UART / module wake-up.
Data sent by the module is correctly received by the DTE if it is ready to receive
data, otherwise data is lost.
3
Enabled (AT&K3)
ON
ON
Data sent by the DTE is correctly received by the module.
Data sent by the module is correctly received by the DTE.
3
Enabled (AT&K3)
ON
OFF
Data sent by the DTE is lost by the module.
Data sent by the module is correctly received by the DTE.
3
Enabled (AT&K3)
OFF
ON
Data sent by the DTE is correctly received by the module.
Data sent by the module is buffered by the module and will be correctly
received by the DTE when it is ready to receive data (i.e.
RTS
line will be ON).
3
Enabled (AT&K3)
OFF
OFF
Data sent by the DTE is lost by the module.
Data sent by the module is buffered by the module and will be correctly
received by the DTE when it is ready to receive data (i.e.
RTS
line will be ON).
3
Disabled (AT&K0)
ON or OFF
ON
Data sent by the DTE is correctly received by the module.
Data sent by the module is correctly received by the DTE if it is ready to receive
data, otherwise data is lost.
3
Disabled (AT&K0)
ON or OFF
OFF
Data sent by the DTE is lost by the module.
Data sent by the module is correctly received by the DTE if it is ready to receive
data, otherwise data is lost.
Table 28: UART and power-saving summary
AT+UPSV=0: power saving disabled, fixed active-mode
The module does not enter idle-mode and the UART interface is enabled (data can be sent and received): the
CTS
line is always held in the ON state after UART initialization. This is the default configuration.
AT+UPSV=1: power saving enabled, cyclic idle/active mode
When the DTE issues the AT+UPSV=1 command, the UART is immediately disabled.
Afterwards, the UART of LISA-U2 series modules is periodically enabled to receive or send data and, if data has
not been received or sent over the UART, the interface is automatically disabled whenever possible according to
the timeout configured by the second parameter of the +UPSV AT command.
The module automatically enters the low power idle-mode whenever possible but it wakes up to active-mode
according to the UART periodic wake up so that the module cyclically enters the low power idle-mode and the
active-mode. Additionally, the module wakes up to active-mode according to any required activity related to the
network or any other required activity related to the functions / interfaces of the module.
The UART is enabled, and the module does not enter low power idle-mode, in the following cases:
During the periodic UART wake up to receive or send data
If the module needs to transmit some data over the UART (e.g. URC)
If a character is sent by the DTE with HW flow control disabled, the first character sent causes the system
wake-up due to the “wake up via data reception” feature described in the following subsection, and the
UART will be then kept enabled after the last data received according to the timeout set by the second
parameter of the AT+UPSV=1 command
The module, outside an active call, periodically wakes up from idle-mode to active-mode to monitor the paging
channel of the current base station (paging block reception), according to 2G or 3G discontinuous reception
(DRX) specification.
