Advantech AIMB-250 User Manual

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User’s Manual 
AIMB-250 User’s Manual 
 
21
 
1.6.7 
IDE Interface (Bus Master Capability and Synchronous DMA Mode ) 
The fast IDE interface supports up to four IDE devices providing an interface for IDE hard 
disks and ATAPI devices. Each IDE device can have independent timings. The IDE 
interface supports PIO IDE transfers up to 16 Mbytes/sec and Ultra ATA transfers up 100 
Mbytes/sec. It does not consume any ISA DMA resources. The IDE interface integrates 
16x32-bit buffers for optimal transfers. 
The ICH4’s IDE system contains two independent IDE signal channels. They can be 
electrically isolated independently. They can be configured to the standard primary and 
secondary channels (four devices). There are integrated series resistors on the data and 
control lines. 
Access to these controllers is provided by two standard IDC 40-pin connectors. 
1.6.8 USB 
2.0 
The ICH4 contains an Enhanced Host Controller Interface (EHCI) compliant host controller 
that supports USB high-speed signaling. High-speed USB 2.0 allows data transfers up to 
480Mb/s which is 40 times faster than full-speed USB. The ICH4 also contains three 
Universal Host Controller Interface (UHCI) controllers that support USB full-speed and 
low-speed signaling. 
The ICH4 supports 6 USB 2.0 ports.    All six USB ports are high-speed, full-speed, and 
low-speed capable. ICH4’s port-routing logic determines whether a USB port is controlled 
by one of the UHCI controllers or by the EHCI controller. 
1.6.9 
VIA VT1616 Audio Codec 
VIA Technologies’ VT1616TM 18-bit audio codec conforms to the AC’97 2.2 specifications. 
The VT1616 integrates Sample Rate Converters on all channels and can be adjusted in 
1Hz increments. There is a provision in hardware for down-mixing the 6 channels into 
stereo when only two end points are available. The analog mixer circuitry integrates a 
stereo enhancement to provide a pleasing 3D surround sound effect for stereo media. This 
codec is designed with aggressive power management to achieve low power consumption. 
When used with a 3.3V analog supply, power consumption is further reduced. The primary 
applications for this part are desktop and portable personal computers multimedia 
subsystems.