Modem User Manual

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8 Embedded Applications
The wireless modem has the capability to store and run customer written code in the
form of a script during the processor’s idle time, through the use of an on board
interpreter.
8.1 Features
Main features of embedded applications are as follows:
• C-based scripting language (Sony Ericsson specific)
• Over the air upgrade of scripts (NOT GSM software)
• Library of intrinsic functions
• 2 scripts can be stored in the memory at any time (but only 1 can be active)
8.2 Implementation
The wireless modem has up to 128k of space available for storage of two scripts in
the scripting language and 100k of operating RAM. Structures included in this
language are:
• If - then - else statements
• While loops
• For loops
All hardware interfaces that are normally available to the wireless modem through
the AT commands are available to the embedded application.
Further drivers have been written such as M bus, keypad, SPI and I2C for use by the
embedded application (EA) through the use of the I/O pins.
8.2.1 Limitations
Since the wireless modem is processing the script using its own memory, limitations
are placed onto the scripts that are run.
A direct comparison cannot be made to a fully compiled C program in terms of size,
but a gauge of script size is that if each line were 128 characters long in the script
then the script could be about 1600 lines long.
Processing power is something that needs to be considered as the script is run as a
low priority process within the software. However, controller mode stops GSM
operation and provides all the processing power for the script to be run. See the
M2mpower Application Guide
for more details.