Compaq AlphaPC 264DP Technical Reference Manual page 19

1.1.5 PCI Interface
The PCI interface provides a PCI speed of 33 MHz. The Cypress CY82C693UB
(southbridge) provides the following:
•
PCI-to-ISA bridge
•
PCI to IDE interface
•
Real-time clock support
•
Mouse and keyboard controller
The PCI to SCSI interface is derived from the Adaptec AIC7895 controller
(AIC7895). The AIC7895 supports two separated ultrawide SCSI ports.
The PCI has five dedicated 64-bit slots and one shared 64-bit slot. The one shared
slot also provides a 16-bit ISA expansion slot. Six expansion slots in total are sup-
ported—six PCI, or five PCI and one ISA.
The two PCI buses are configured as follows:
•
PCI bus 0: contains Pchip0, southbridge, Adaptec SCSI, and three 64-bit expan-
sion slots
•
PCI bus 1: contains Pchip1 and three 64-bit expansion slots
1.1.6 ISA Interface
The ISA bus provides an expansion bus and the following system support functions:
•
The ISA bus has one shared expansion slot with the PCI.
•
An SMC FDC37C669 super I/O controller chip is used as the combination con-
troller chip that provides a diskette controller, two universal, asynchronous
receiver/transmitters (UARTs) for com ports, and a parallel port.
1.1.7 IDE Interface
The integrated drive electronics (IDE) provides an additional expansion bus, with
one connector on the mainboard.
Only CD-ROMs with an IDE cable length of 12 inches or less are sup-
Note:
ported.
12 February 1999 – Subject To Change
System Components and Features
AlphaPC 264DP Introduction
1–5