Intel D945GCLF2 - Manual (Page 19)

Product Description
19
1.6.3 IDE Support
The board provides three IDE interface connectors:
• One parallel ATA IDE connector that supports two devices
• Two serial ATA connectors that support one device per connector
1.6.3.1 Parallel ATE IDE Interface
The ICH7’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.
• Ultra DMA: DMA protocol on IDE bus supporting host and target throttling and
transfer rates of up to 33 MB/sec.
• ATA-66: DMA protocol on IDE bus supporting host and target throttling and
transfer rates of up to 66 MB/sec. ATA-66 protocol is similar to Ultra DMA and is
device driver compatible.
• ATA-100: DMA protocol on IDE bus allows host and target throttling. The ICH7’s
ATA-100 logic can achieve read transfer rates up to 100 MB/sec and write transfer
rates up to 88 MB/sec.
NOTE
ATA-66 and ATA-100 are faster timings and require a specialized cable to reduce
reflections, noise, and inductive coupling.
The Parallel ATA IDE interface also supports ATAPI devices (such as CD-ROM drives)
and ATA devices using the transfer modes.
The BIOS supports Logical Block Addressing (LBA) and Extended Cylinder Head Sector
(ECHS) translation modes. The drive reports the transfer rate and translation mode to
the BIOS.
For information about Refer to
The location of the Parallel ATA IDE connector Figure 9, page 42
1.6.3.2 Serial ATA Interfaces
The ICH7’s Serial ATA controller offers two independent Serial ATA ports with a
theoretical maximum transfer rate of 3 Gbits/sec per port. One device can be installed
on each port for a maximum of two Serial ATA devices. A point-to-point interface is
used for host to device connections, unlike Parallel ATA IDE which supports a
master/slave configuration and two devices per channel.
For compatibility, the underlying Serial ATA functionality is transparent to the
operating system. The Serial ATA controller can operate in both legacy and native
modes. In legacy mode, standard IDE I/O and IRQ resources are assigned (IRQ 14
and 15). In Native mode, standard PCI Conventional bus resource steering is used.
Native mode is the preferred mode for configurations using the Windows* XP and
Windows Vista* operating systems.