Integration Manual

Table Of Contents
TOBY-L2 and MPCI-L2 series - System Integration Manual
UBX-13004618 - R26 System description
Page 55 of 162
Figure 25 shows the case where in addition to the wake-up character further (valid) characters are sent. The wake
up character wakes-up the module UART. The other characters must be sent after the “wake up time” of ~5 ms.
If this condition is satisfied, the module (DCE) recognizes characters. The module will disable the UART after 2000
GSM frames from the latest data reception.
Wake up character
Not recognized by DCE
Valid characters
Recognized by DCE
DCE UART is enabled for 2000 GSM frames (~9.2s)
after the last data received
time
Wake up time: ~5 ms
time
OFF
ON
TXD input
UART
OFF
ON
Figure 25: Wake-up via data reception with further communication
The “wake-up via data reception” feature cannot be disabled.
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
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, 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 [11], 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 [12]):
Channel 0: control channel
Channel 1 5: AT commands / data connection
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See the u-blox AT Commands Manual [3] for the definition of the interface data mode, command mode and online command mode.