Advantech PCM-9362 Series, Руководство пользователя

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51 PCM-9362 User Manual
Chapter 4
S
/W Introduction
&
Installation
Application programmers can invoke the functions exported by SUSI instead of call-
ing 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 catego-
ries including Watchdog, I
2
C, SMBus, GPIO, and VGA control. Each category of API
in SUSI is briefly described below.
4.3.2 Software APIs
4.3.2.1 The GPIO API
General Purpose Input/Output is a flexible parallel interface that allows a variety of
custom connections. It allows users to monitor the level of signal input or set the out-
put status to switch on/off a device. Our API also provides Programmable GPIO,
which allows developers to dynamically set the GPIO input or output status.
4.3.2.2 The I
2
C API
I
2
C is a bi-directional two-wire bus that was developed by Phillips for use in their tele-
visions in the 1980s and nowadays is used in various types of embedded systems.
The strict timing requirements defined in the I
2
C protocol has been taken care of by
SUSI. Instead of asking application programmers to figure out the strict timing
requirements in the I
2
C protocol, the I
2
C API in SUSI can be used to control I
2
C
devices by invoking other function calls. SUSI provides a consistent programming
interface for different Advantech boards. That means user programs using SUSI are
portable among different Advantech boards as long as the boards and SUSI provide
the required functionalities. Overall product development times can be greatly
reduced using SUSI.
4.3.2.3 The SMBus API
The System Management Bus (SMBus) is a two-wire interface defined by Intel® Cor-
poration in 1995. It is based on the same principles of operation of I2C and is used in
personal computers and servers for low-speed system management communica-
tions. Nowadays, it can be seen in many types of embedded systems. As with other
API in SUSI, the SMBus API is available on many platforms including Windows XP
and Windows CE.
4.3.2.4 The Display Control API
There are two kinds of VGA control APIs, backlight on/off control and brightness con-
trol. Backlight on/off control allows a developer to turn on or off the backlight, and to
control brightness smoothly.
1. Brightness Control
– The Brightness Control API allows a developer to interface with an embed-
ded device to easily control brightness.
2. Backlight Control
– The Backlight API allows a developer to control the backlight (screen) on/off
in an embedded device.