Advantech MIO-2270, Руководство пользователя

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43 MIO-2270 User Manual
Chapter 4
S
/W Introduction
and
Installation
4.3.2 Software APIs
4.3.2.1 GPIO API
The General Purpose Input/Output (GPIO) API is a flexible parallel interface that
enables various custom connections and allows users to monitor the signal input
level or set the output status to switch on/off a device. This API also facilitates pro-
grammable GPIO, which allows developers to dynamically set the GPIO input or out-
put status.
4.3.2.2 SMBus API
The System Management Bus (SMBus) API is a two-wire interface established by
Intel Corporation in 1995, based on the same operation principles of I
2
C, and used in
personal computers and servers for low-speed system management communica-
tions. At present, SMBus is incorporated in many types of embedded systems. Simi-
lar to other SUSI APIs, the SMBus API is available on numerous platforms including
Windows 7.
4.3.2.3 Display Control API
Two VGA control APIs exist; one for backlight on/off control, and one for brightness
control. These APIs allow developers to turn the backlight on or off and to control the
brightness.
1. Brightness Control
– The Brightness Control API allows developers to interface with an embedded
device and adjust the display brightness.
2. Backlight Control
– The Backlight API allows developers to control the backlight (screen) of an
embedded device.
4.3.2.4 Watchdog API
A watchdog timer (WDT) is a hardware device that triggers a specific action, e.g.,
system reboot, if the system does not reset the timer within a specified period of time.
The WDT API in SUSI enables developers to start the timer, reset the timer, and set
the timeout value for hardware that requires customized timeout values.
4.3.2.5 Hardware Monitor API
The hardware monitor (HWM) enables system health supervision using I/O chips
combined with sensors to monitor certain condition indices, such as fan speed, tem-
perature, voltage, etc.
However, because of the inaccuracy of many commercial hardware monitoring chips,
Advantech developed a unique scheme for hardware monitoring; that is, using a ded-
icated microprocessor and specifically designed algorithms to provide accurate and
reliable real-time data to ensure system protection.
4.3.2.6 Power Saving API
1. CPU Speed
– The Power Saving API uses Intel SpeedStep® technology to reduce the sys-
tem power consumption. The CPU speed is automatically adjusted according
to the system load.
2. System Throttling
– System throttling refers to various methods for reducing power consumption
by lowering the clock frequency. The Power Saving API allows users to
reduce the clock frequency from 87.5% to 12.5%.