LEON-G100 / LEON-G200 - System Integration Manual
GSM.G1-HW-09002-G3
Preliminary
System description
Page 54 of 125
It is highly recommended to provide on an application board a direct access to
RxD
and
TxD
lines of the
module (in addition to access to these lines from an application processor). This enables a direct
connection of PC (or similar) to the module for execution of Firmware upgrade over the UART. The
module FW upgrade over UART (using the
RxD
and
TxD
pins) starts at the module switch-on or when
the module is released from the reset state: it is suggested to provide access to the
PWR_ON
pin, or to
provide access to the
RESET_N
pin, or to provide access to the enabling of the DC supply connected to
the
VCC
pin, to start the module firmware upgrade over the UART.
1.9.1.5
MUX Protocol (3GPP 27.010)
The module has a software layer with MUX functionality complaint with
3GPP 27.010
This is a data link protocol (layer 2 of OSI model) using HDLC-like framing and operates between the module
(DCE) and the application processor (DTE). The protocol allows simultaneous sessions over the UART. Each
session consists of a stream of bytes transferring various kinds of data like SMS, CBS, GPRS, AT commands in
general. This permits, for example, SMS to be transferred to the DTE when a data connection is in progress.
The following channels are defined:
Channel 0: control channel
Channel 1 – 5: AT commands /data connection
Channel 6: GPS tunneling
For more details refer to
GSM Mux implementation Application Note