Wetif VMT12, User Manual

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5.3 Value-Added Software Services
Software API: An interface that defines the ways by which an application
program may request services from libraries and/or operating systems.
Provides not only the underlying drivers required but also a rich set of
user-friendly, intelligent and integrated interfaces, which speeds
development, enhances security and offers add-on value for Advantech
platforms. It plays the role of catalyst between developer and solution, and
makes Advantech embedded platforms easier and simpler to adopt and
operate with customer applications.
5.3.1 SUSI Introduction
To make hardware easier and convenient to access for programmers,
Advantech has released a suite of API (Application Programming Interface)
in the form of a program library. The program Library is called Secured
and Unified Smart Interface or SUSI for short.
In modern operating systems, user space applications cannot access
hardware directly. Drivers are required to access hardware. User space
applications access hardware through drivers. Different operating
systems usually define different interface for drivers. This means that
user space applications call different functions for hardware access in
different operating systems. To provide a uniform interface for accessing
hardware, an abstraction layer is built on top of the drivers and SUSI is
such an abstraction layer. SUSI provides a uniform API for application
programmers to access the hardware functions in different Operating
Systems and on different Advantech hardware platforms.
Application programmers can invoke the functions exported by SUSI
instead of calling the drivers directly. The benefit of using SUSI is
portability. The same set of API is defined for different Advantech
hardware platforms. Also, the same set of API is implemented in different
Operating Systems including Windows XP and Windows CE. This user’s
manual describes some sample programs and the API in SUSI. The
hardware functions currently supported by SUSI can be grouped into a
few categories including Watchdog, I2C, SMBus, GPIO, and VGA control.
Each category of API in SUSI is briefly described below.