LISA-U2 series - System integration manual
UBX-13001118 - R27
System description
Page 85 of 183
C1-Public
channel. The multiplexer protocol can be used on one serial interface (UART or SPI) at a time. Each
session consists of a stream of bytes transferring various kinds of data such as SMS, CBS, PSD,
GNSS, and AT commands in general. This permits, for example, SMS to be transferred to the DTE
when a data connection is in progress.
The following virtual channels are defined:
•
Channel 0: control channel
•
Channel 1
–
5: AT commands / data connection
•
Channel 6: GNSS tunneling
•
Channel 7: SAP (SIM Access Profile)
For more details, see the Mux implementation application note
☞
If the module switch-off AT command +CPWROFF is issued over a multiplexer channel, the
completion of the module power-off sequence could require up to 2.5 s, after the module OK reply.
Therefore, if the application processor (AP) controls the
VCC
supply of the module, the AP should
disable the multiplexer protocol and then issue the AT+CPWROFF command over the used AT
interface, or otherwise the AP should issue the AT+CPWROFF command over a multiplexer
channel and wait 2.5 s after OK reception before removing the module
VCC
supply.
