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LISA-U1 series - System Integration Manual
3G.G2-HW-10002-3
Preliminary
System description
Page 56 of 125
recommended to provide direct access to
VUSB_DET
,
USB_D+
,
USB_D-
lines for execution of firmware
upgrade over USB and for debug purpose. In both cases, provide as well access to
RESET_N
pin, or to
the
PWR_ON
pin, or enable the DC supply connected to the
VCC
pin to start the module firmware
upgrade (see
Firmware Update Application Note
If the UART interface is not used, all the UART interface pins can be left unconnected, but it is highly
recommended to provide direct access to the
RxD
,
TxD
,
CTS
and
RTS
lines for execution of firmware
upgrade and for debug purpose.
1.9.3
USB interface
LISA-U1 series modules provide a high-speed USB interface at 480 Mb/s compliant with the
Universal Serial Bus
[7]. It acts as a USB device and can be connected to any USB host such as a PC or other
Application Processor.
The USB-device shall look for all upper-SW-layers like any other serial device. This means that LISA-U1 series
modules emulate all serial control logical lines.
If the logical DTR line isn't enabled by the USB host, the module doesn’t answer to AT commands by the
USB interface.
Name
Description
Remarks
VUSB_DET
USB detect input
Apply 5 V typical to enable USB
USB_D+
USB Data Line D+
90
Ω
nominal differential impedance.
Pull-up or pull-down resistors and external series resistors as
required by the
USB 2.0 high-speed specification
[7] are part
of the USB pad driver and need not be provided externally.
USB_D-
USB Data Line D-
90
Ω
nominal differential impedance.
Pull-up or pull-down resistors and external series resistors as
required by the
USB 2.0 high-speed specification
[7] are part
of the USB pad driver and need not be provided externally.
Table 21: USB pins
The USB interface pins ESD sensitivity rating is 1 kV (Human Body Model according to JESD22-A114F).
Higher protection level could be required if the lines are externally accessible on the application board.
Higher protection level can be achieved by mounting a very low capacitance (i.e. less or equal to 1 pF)
ESD protection (e.g. Tyco Electronics PESD0402-140 ESD protection device) on the lines connected to
these pins.
1.9.3.1
USB features
LISA-U1 series modules simultaneously support 6 USB CDC (Communications Device Class) that assure multiple
functionalities to the USB physical interface. The 6 available CDCs are configured as described in the following
list:
USB1: AT commands / data connection
USB2: AT commands / data connection
USB3: AT commands / data connection
USB4: GPS tunneling dedicated port
USB5: 2G and BB trace dedicated port
USB6: 3G trace dedicated port
The user can concurrently use AT command interface on one CDC and Packet-Switched / Circuit-Switched Data
communication on another CDC.