PI7C7300 datasheet(40/109 Pages) PERICOM

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PI7C7300A

3-PORT PCI-TO-PCI BRIDGE

ADVANCE INFORMATION

Page 40 OF 109

09/25/03 Revision 1.09

PI7C7300A returns a target disconnect to an initiator when one of the following

conditions is met:

PI7C7300A hits an internal address boundary.

PI7C7300A cannot accept any more write data.

PI7C7300A has no more read data to deliver.

See Section 4.6.4 for a description of write address boundaries, and Section 4.7.3 for a

description of read address boundaries.

4.9.4.3

TARGET ABORT

PI7C7300A returns a target abort to an initiator when one of the following conditions is

met:

PI7C7300A is returning a target abort from the intended target.

When PI7C7300A returns a target abort to the initiator, it sets the signaled target abort

bit in the status register corresponding to the initiator interface.

4.10

CONCURRENT MODE OPERATION

The Bridge can be configured to run in concurrent operation. Concurrent operation is

defined as cycles going from one device on one secondary bus to another device on the

same or other secondary bus. This off-loads traffic from the primary bus, allowing other

traffic to run on the primary bus concurrently.

The Bridge is already configured to handle concurrent operation. However, the devices

themselves need to be configured to do so. Meaning, device drivers for the specific

device used will have to be configured to perform the operation. Please see section 5.1

for more information on addressing.

ADDRESS DECODING

PI7C7300A uses three address ranges that control I/O and memory transaction

forwarding. These address ranges are defined by base and limit address registers in the

configuration space. This chapter describes these address ranges, as well as ISA-mode

and VGA-addressing support.

5.1

ADDRESS RANGES

PI7C7300A uses the following address ranges that determine which I/O and memory

transactions are forwarded from the primary PCI bus to the secondary PCI bus, and from

the secondary bus to the primary bus:

PI7C7300 Datasheet(PDF) 40 Page - Pericom Semiconductor Corporation