Intel AP440FX specifications IDE Support, Secure Flash Support, USB Support

AP440FX Motherboard Technical Product Specification

1.7.4IDE Support

The motherboard provides two independent high performance bus-mastering PCI IDE interfaces capable of supporting PIO Mode 3 and Mode 4 devices. The BIOS supports Logical Block Addressing (LBA) and Extended Cylinder Sector Head (ECHS) translation modes as well as ATAPI (e.g., CD-ROM) devices on both IDE interfaces. Detection of IDE device transfer rate and translation mode capability is automatically determined by the BIOS.

Normally, programmed I/O operations require a substantial amount of microprocessor bandwidth. In true multi-tasking operating systems like Windows† 95, the microprocessor bandwidth freed up by using PCI bus mastering IDE can be used to complete other tasks while disk transfers are occurring. When used in conjunction with the appropriate driver for the Windows 95 environment, the IDE interface can operate as a PCI bus master capable of supporting PIO Mode 4 devices with transfer rates of up to 16 MB/sec.

Detailed information on the PCIset is available in the Intel 82440FX PCISet data sheet.

1.7.5Secure Flash Support

The AP440FX motherboard uses both onboard hardware and BIOS code support to protect the onboard flash memory device from accidentally or intentionally being corrupted. A general purpose I/O (GPIO) port of the I/O controller is used to control the write enable line of the flash device. By putting the microprocessor in System Management Mode (SMM) whenever the flash write is enabled, the BIOS can ensure that the SMM code is not corrupted and that flash can only be written from within SMM.

1.7.6USB Support

The AP440FX motherboard has two USB ports. This permits connection of two USB peripheral devices directly to the computer without an external hub. If more devices are required, an external hub can be connected to either of the built-in ports. The motherboard completely supports the standard universal host controller interface (UHCI) and takes advantage of the standard software drivers written to be compatible with UHCI. Features of the USB include:

∙Self-identifying peripherals

∙Automatic mapping of function to driver and configuration

∙Support for isochronous and asynchronous transfer types over the same set of wires

∙Support for up to 127 physical devices

∙Guaranteed bandwidth and low latencies appropriate for telephony, audio, and other applications

∙Error handling and fault recovery mechanisms built into protocol

∙Low cost cables and connectors

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