1. Functional Overview
28
PowerSpan II User Manual
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Integrated Device Technology
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Figure 4: Concurrent Read Process with PowerSpan II
When Master 2 makes its first read request in Step 2, it is retried but information about the read request
is latched and initiates a read on the other bus. This occurs even though a read is in progress for
Master 1.
PowerSpan II can simultaneously support two reads to the Processor Bus and two reads to the PCI bus.
1.6.1.1
Conventional Reads and Retries
In conventional FIFO-based bridge architectures, bus masters must take turns for read opportunities
and incur multiple retries while waiting.
illustrates the read process for subsequent reads where
retries are incurred while a pending read is completed.
Master 1: Makes a read request
and is retried.
READ 1 Request
READ 1
Read Request
Master 2: Makes an initial read
request and is retried.
READ 2
Master 1: Takes the read data
Master 2: Takes read data
Read Request
Master 1: Makes request
1.
2.
3.
4.
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 ...