TOBY-L2 and MPCI-L2 series - System Integration Manual
UBX-13004618 - R28
System description
Page 54 of 164
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The “wake-up via data reception” feature cannot be disabled.
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In command mode
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, with “wake-up via data reception” enabled and autobauding enabled, the DTE
should always send a dummy character to the module before the “AT” prefix set at the beginning
of each command line: the first dummy character is ignored if the module is in active-mode, or it
represents the wake-up character if the module is in low power idle-mode.
☞
In command mode
, with “wake-up via data reception” enabled and autobauding disabled, the DTE
should always send a dummy “AT” to the module before each command line: the first dummy “AT”
is not ignored if the module is in active-mode (i.e. the module replies “OK”), or it represents the
wake up character if the module is in low power idle-mode (i.e. the module does not reply).
Additional considerations
If the USB is connected and not suspended, the module is forced to stay in active-mode, therefore the
AT+UPSV settings are overruled but they have effect on the UART behavior (they configure UART
power saving, so that UART is enabled / disabled according to the AT+UPSV settings).
1.9.2.5
UART multiplexer protocol
TOBY-L2 series modules include multiplexer functionality as per 3GPP TS 27.010
, on the UART
physical link.
This is a data link protocol which uses HDLC-like framing and operates between the module (DCE) and
the application processor (DTE) and allows a number of simultaneous sessions over the used physical
link (UART): the user can concurrently use AT interface on one MUX channel and data communication
on another MUX channel.
The following virtual channels are defined (for more details, see Mux implementation Application
Note
Channel 0: control channel
Channel 1 – 5: AT commands / data connection
1.9.3
DDC (I
2
C) interface
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The I
2
C bus compatible Display Data Channel interface is not available on the MPCI-L2 series
modules.
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The I
2
C bus compatible Display Data Channel interface is not supported by the TOBY-L2 series
modules “00”, “01”, “60” and TOBY-L201-02S product versions.
The SDA and SCL pins of TOBY-L2 series modules represent an I
2
C bus compatible Display Data
Channel (DDC) interface for the communication with external I
2
C devices as audio codecs: an I
2
C
master can communicate with more I
2
C slaves in accordance to the I
2
C bus specifications
The AT commands interface is not available on the DDC (I
2
C) interface.
DDC (I
2
C) slave-mode operation is not supported: the TOBY-L2 modules can act as I
2
C master only.
The DDC (I
2
C) interface pads of the module, serial data (SDA) and serial clock (SCL), are open drain
output and external pull up resistors must be used conforming to the I
2
C bus specifications
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See the u-blox AT Commands Manual
for the definition of data mode, command mode and online command mode.