Intel D925XBC User Manual

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Product Description 
1.7 Intel
®
 925X Chipset 
The Intel 925X chipset consists of the following devices: 
•  Intel 82925X Memory Controller Hub (MCH) with Direct Media Interface (DMI) interconnect 
•  Intel 82801FR I/O Controller Hub (ICH6-R) with DMI interconnect 
•  Firmware Hub (FWH) 
The MCH is a centralized controller for the system bus, the memory bus, the PCI Express bus, and 
the DMI interconnect.  The ICH6-R is a centralized controller for the board’s I/O paths.  The FWH 
provides the nonvolatile storage of the BIOS.   
 
For information about  
Refer to 
The Intel 925X chipset 
 
Resources used by the chipset  
Chapter 2 
1.7.1 USB 
The boards support up to eight USB 2.0 ports, supports UHCI and EHCI, and uses UHCI- and 
EHCI-compatible drivers.   
The ICH6-R provides the USB controller for all ports.  The port arrangement is as follows: 
•  Four ports are implemented with dual stacked back panel connectors adjacent to the audio 
connectors 
•  Four ports are routed to two separate front panel USB connectors 
 
NOTES 
•  Computer systems that have an unshielded cable attached to a USB port may not meet FCC 
Class B requirements, even if no device is attached to the cable.  Use shielded cable that meets 
the requirements for full-speed devices.  
 
For information about  
Refer to 
The location of the USB connectors on the back panel 
Figure 20, page 66 
The location of the front panel USB connectors on the Desktop Board D925XCV  Figure 21, page 68 
The location of the front panel USB connectors on the Desktop Board D925XBC  Figure 22, page 70 
1.7.2 IDE 
Support 
The board provides five IDE interface connectors: 
•  One parallel ATA IDE connector, which supports two devices 
•  Four serial ATA IDE connectors, which support one device per connector 
1.7.2.1  Parallel ATE IDE Interface 
The ICH6-R’s Parallel ATA IDE controller has one bus-mastering Parallel ATA IDE interface.  
The Parallel ATA IDE interface supports the following modes: 
•  Programmed I/O (PIO):  processor controls data transfer. 
•  8237-style DMA:  DMA offloads the processor, supporting transfer rates of up to 16 MB/sec. 
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