6. Arbitration
140
PowerSpan II User Manual
80A1010_MA001_09
Integrated Device Technology
www.idt.com
Figure 21: Arbitration Algorithm
Each PowerSpan II PCI arbiter is programmable with the corresponding arbiter control register (see
“PCI-1 Bus Arbiter Control Register” on page 284
) and enabled through power-up option PCI x
Arbiter enable (PWRUP_Px_ARB_EN) (see
“Resets, Clocks and Power-up Options” on page 167
).
Each master has a arbitration level for PCI Master Device x (Mx_PRI) bit in the
(Px_ARB_CTRL) to determine its arbitration level.
External Arbitration
When an external arbiter is used, the PowerSpan II PCI Master uses Px_REQ#[1]/Px_GNT#[1] to
acquire the bus.
Master X
Master Y
Master Z
Level 0
Master C
Level 0
Master A
Master B
Level 1
Arbitration Order
Level 1, Level 1, Level 1, Level 0
For example, if all bus masters
assert Request:
* A, B, C, X
* A, B, C, Y
* A, B, C, Z
* A, B, C, X
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 ...