B. Typical Applications
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PowerSpan II User Manual
80A1010_MA001_09
Integrated Device Technology
www.idt.com
The PowerQUICC II is the system memory controller being used in this application in order to manage
64-bit wide SDRAM. The PowerQUICC II has processor bus master and slave capability. As a bus
master in this system it can access SDRAM and PCI. The address latch and multiplexor allow the
external processor bus agents, the PowerPC 7xx, and PowerSpan II to access PowerQUICC II
controlled memory. Additionally, the PowerPC 7xx and PowerSpan II can program PowerQUICC II
registers and master the PowerQUICC II local bus.
The PowerSpan II processor bus arbiter controls system boot. Boot can be selected from PCI by
configuring the arbiter at power-up to ignore all external requests on Bus Request (PB_BR[3:1]_). This
allows an external PCI master to configure the PowerQUICC II memory controller and load system
boot code before enabling recognition of requests on PB_BR[3:1]_.
Alternatively, at power-up the processor bus arbiter is configured to recognize requests on PB_BR[1]_
and ignore requests on PB_BR[3:2]_. In this case the processor connected to PB_BR[1]_ enables
recognition of requests from other masters when its system configuration tasks are complete.
B.2.2
CompactPCI Adapter Card
A common PowerSpan II application is the support of PowerQUICC II based CompactPCI adapter
cards. These cards are installed in peripheral slots of the CompactPCI chassis.
PowerSpan II is in a dual PowerQUICC II application. One processor is selected to be the
Configuration master (RSTCONF_ is tied low) while the second processor, and PowerSpan II, are
configuration slaves.
Optionally, the second processor could have the PowerPC core disabled and be used strictly to provide
more serial interface capability.
PowerSpan II’s PCI-1 Interface is designated as the Primary Interface, through power-up option, and is
connected to the CompactPCI backplane. It is possible to designate either PCI-1 or PCI-2 as the
Primary Interface with a power-up option. The backplane supplies reset, clock and central resource
functionality. The Secondary PCI Interface, PCI- 2, connects to a secondary PCI system on the card
and provides reset and arbitration for the secondary bus.