1. Functional Overview
24
PowerSpan II User Manual
80A1010_MA001_09
Integrated Device Technology
www.idt.com
1.2
PCI Interface
PowerSpan II is available as a Single PCI PowerSpan II or Dual PCI PowerSpan II. A 64-bit PCI
Interface is available on both variants; the Dual PCI PowerSpan II has a 32-bit PCI Interface in
addition to the 64-bit PCI Interface. In both cases, the PCI Interfaces on the PowerSpan II support
66MHz operation and are asynchronous to the other interfaces on the device.
The PCI interfaces are
PCI 2.2 Specification
compliant.
1.2.1
PCI-to-PCI Bridge
The Dual PCI PowerSpan II is a PCI-to-PCI bridge. It connects traffic between the two PCI interfaces.
This PCI-to-PCI bridging function is “non-transparent”. In a non-transparent bridge one PCI bus is
hidden from system BIOS running in the other PCI domain. Memory and I/O transfers pass freely
between the PCI interfaces, but Configuration accesses are filtered.
The application is shown in
Programmable DMA Block Size
PowerSpan II enables programmable DMA block sizes.
and
“Register Descriptions”
on page 235
PB Arbiter Qualifies Bus Grants
The PowerSpan II PB Arbiter can be programmed to qualify data bus grants before issuing data bus
grants.
Target Fast Back to Back Capable (TFBBC)
The default setting of this bit was changed to 0 in PowerSpan II; the device does not support fast
back-to-back transactions.
“Register Descriptions”
on page 235
Table 2: PowerSpan II Functional Enhancements
Functional Enhancement Descriptions
See