GT-64260A Design Guide
Doc. No. MV-S300165-00, Rev. A
CONFIDENTIAL
Copyright © 2002 Marvell
Page 128
Document Classification: Proprietary Information
May 21, 2002, Preliminary
Section 16. PCI Interface Design Considerations
The PCI interface is used to connect the GT-64260A and other PCI devices. The GT-64260A supports two 64-bit
PCI interfaces (named PCI0 and PCI1), compliant to PCI specification, Rev. 2.2.
16.1 Interface Connectivity
The PCI interfaces connectivity complies to the PCI specification, Rev. 2.2.
16.2 Electrical Definition
The PCI electrical definition provides for both 5V and 3.3V signaling environments.
Do not confuse the "signaling environments" with 5V and 3.3V component technologies. A "5V component" can be
designed to work in a 3.3V signaling environment and vice versa. Component technologies can be mixed in either
signaling environment. The signaling environments cannot be mixed; all components on a given PCI bus must use
the same signaling convention of 5V or 3.3V.
For more information on the PCI interface electrical definition, see the "Electrical Specification" section in the PCI
specification.
16.3 Termination Topology
In configurations where non-terminated trace ends propagate a significant distance from a PCI component (e.g., a
section of unpopulated PCI connectors), it may be necessary to add active (e.g., diode) termination at the
unloaded end of the bus, to insure adequate signal quality.
Note
Since the signaling protocol depends on the initial reflection, passive termination does not work.
16.4 Timing Requirements
and
to determine the required AC timings for PCI specifications and GT-64260A PCI inter-
faces.
Note
The AC timing might be updated in the PCI specification or in the GT-64260A datasheet. Make sure you
have the most update documents. For every conflict between this document and the specifications