1. Functional Overview
30
PowerSpan II User Manual
80A1010_MA001_09
Integrated Device Technology
www.idt.com
1.6.2.2
Adapter Card
In an adapter card application, the read latency problem is a mirror image of a PCI host bridge
application. In an adapter card, the PowerQUICC II serial ports (FCCs) may be expected to transfer bit
streams through the PowerQUICC II/PCI to host memory across the PCI bus. In this case, there can be
eight separate FCCs potentially contending for the processor slave interface in the PCI bridge
—
assuming there are two PowerQUICC IIs on the local bus. This architecture adds considerable latencies
to read transactions because of FCCs attempting reads to host memory across the PCI bus. Ideally, each
FCC would have a dedicated channel to the PCI bus so they do not have to share resources.
PowerSpan II supports this ideal situation through its concurrent reads in a flexible switching
architecture. The PCI bridge latches information about the local read as it receives the read request
even with reads pending. The FCCs can now receive transmit data from system host memory with far
lower latencies.
Содержание PowerSpan II
Страница 8: ...Contents 8 PowerSpan II User Manual 80A1010_MA001_09 Integrated Device Technology www idt com ...
Страница 14: ...List of Tables 14 PowerSpan II User Manual 80A1010_MA001_09 Integrated Device Technology www idt com ...
Страница 18: ...About this Document 18 PowerSpan II User Manual 80A1010_MA001_09 Integrated Device Technology www idt com ...
Страница 82: ...2 PCI Interface 82 PowerSpan II User Manual 80A1010_MA001_09 Integrated Device Technology www idt com ...
Страница 112: ...3 Processor Bus Interface 112 PowerSpan II User Manual 80A1010_MA001_09 Integrated Device Technology www idt com ...
Страница 156: ...7 Interrupt Handling 156 PowerSpan II User Manual 80A1010_MA001_09 Integrated Device Technology www idt com ...
Страница 380: ...12 Register Descriptions 380 PowerSpan II User Manual 80A1010_MA001_09 Integrated Device Technology www idt com ...
Страница 394: ...14 Package Information 394 PowerSpan II User Manual 80A1010_MA001_09 Integrated Device Technology www idt com ...
Страница 414: ...15 AC Timing 414 PowerSpan II User Manual 80A1010_MA001_09 Integrated Device Technology www idt com ...
Страница 416: ...16 Ordering Information 416 PowerSpan II User Manual 80A1010_MA001_09 Integrated Device Technology www idt com ...
Страница 420: ...A Hardware Implementation 420 PowerSpan II User Manual 80A1010_MA001_09 Integrated Device Technology www idt com ...
Страница 428: ...B Typical Applications 428 PowerSpan II User Manual 80A1010_MA001_09 Integrated Device Technology www idt com ...
Страница 432: ...Glossary 432 PowerSpan II User Manual 80A1010_MA001_09 Integrated Device Technology www idt com ...