3-22
Falcon ECC Memory Controller Chip Set
3
❏
The tester
❏
The refresher/scrubber
The Falcon pair’s arbiters assign priority with the refresher/scrubber
highest, the tester next, and the PowerPC 60x bus lowest. When no
requests are pending, the arbiter defaults to providing a PowerPC 60x bus
grant. This provides fast response for PowerPC 60x bus cycles. Although
the arbiter operates on a priority basis, it also performs a pseudo round-
robin algorithm in order to prevent starving any of the requesting entities.
Note that PowerPC DRAM or ROM/Flash accesses should not be
attempted while the tester is in operation.
Chip Defaults
Some jumper option kinds of parameters need to be configured by
software in the Falcon pair. These parameters include DRAM and
ROM/Flash attributes. In order to set up these parameters correctly,
software needs some way of knowing about the devices that are being used
with the Falcon pair. One way of providing this information is by using the
power-up status registers in the Falcon pair. At power-up reset, each
Falcon latches the level on its RD0-RD63 signal pins into its power-up
status registers. Since the RD signal pins are high impedance during reset,
their power-up reset level can be controlled by pullup/pulldown resistors.
(They are pulled-up internally.)
External Register Set
Each chip in the Falcon pair has an external register chip select pin which
enables it to talk to an external set of registers. This interface is like the
ROM/Flash interface but with less flexibility. It is intended for the system
designer to be able to implement general-purpose status/control signals
with this external set. Refer to the Programming Model in this chapter for
a description of this register set.
Содержание MVME2700 Series
Страница 1: ...MVME2600 2700 Series Single Board Computer Programmer s Reference Guide V2600A PG2 ...
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Страница 67: ...1 50 Board Description and Memory Maps 1 ...
Страница 70: ...Introduction 2 3 2 Four 31 bit tick timers Two 64 bit general purpose registers for cross processor messaging ...
Страница 151: ...2 84 Raven PCI Host Bridge Multi Processor Interrupt Controller Chip 2 ...
Страница 215: ...3 64 Falcon ECC Memory Controller Chip Set 3 ...
Страница 277: ...Glossary GL 14 G L O S S A R Y ...