Intel 273246-002 4 82371EB PCI to ISA/IDE Xcelerator PIIX4E, Dram, Power, Boot ROM, Legacy I/O

Theory of Operation

3.2.482371EB PCI to ISA/IDE Xcelerator (PIIX4E)

The 82443BX is designed to support the PIIX4E I/O bridge. The PIIX4E is a highly-integrated multifunctional component that supports the following:

•PCI Revision 2.1 compliant PCI-to-ISA bridge with support for 33 MHz PCI operations

•ACPI Power Management support

•Enhanced DMA controller, interrupt controller and timer functions

•Integrated IDE controller with Ultra DMA/33 support

•USB host interface with support for two USB ports

•System Management Bus (SMB) with support for DIMM Serial Presence Detect

3.2.5DRAM

The evaluation board provides two 168-pin DIMM module connectors. The DRAM interface is a 64-bit data path that supports Synchronous DRAM (SDRAM). The DRAM interface supports

4 Mbytes to 256 Mbytes of 4-Mbit, 16-Mbit and 64-Mbit DRAM and SRAM technology (both symmetrical and asymmetrical). Parity is not supported. One 32-Mbyte SDRAM DIMM is included in the kit.

3.2.6Power

The evaluation board uses an industry standard ATX-style power supply with a 20-pin connector. A 230-watt (minimum) supply is recommended. Note that the ATX power connector is keyed to prevent incorrect insertion. See “ATX Power Connector” on page 4-3for a detailed description of the power connector.

Make sure that the ATX power supply is not plugged into the wall when connecting or disconnecting it from the evaluation board.

3.2.7Boot ROM

The system boot ROM installed at U11 is a 2-Mbit 28F002BC flash device. The system is set up for in-circuit reprogramming of the BIOS, but the flash device is also socketed. This device is addressable on the XD bus extension of the ISA bus.

3.2.8RTC/NVRAM

The RTC and NVRAM are contained within the 82371EB PIIX4E device. CMOS NVRAM backup is provided by a 3-V lithium-ion battery.

3.2.9Legacy I/O

Support for legacy I/O functions is provided by the Intel 82371EB PIIX4E and the SMC FDC37B78X SuperI/O* device.

3-4 Celeron™ Processor Development Kit Manual