Glossary-6
MPC106 PCIB/MC User's Manual
MOTOROLA
same location, cached data is typically placed in the set whose
cache
line
corresponding to that address was used least recently.
Slave
. The device addressed by a master device. The slave is identified in the
address tenure/phase and is responsible for supplying or latching the
requested data for the master during the data tenure/phase.
Snooping
. Monitoring addresses driven by a bus master to detect the need for
coherency actions.
Snoop push.
Write-backs
due to a snoop hit. The
cache line
will transition to
an invalid or exclusive state.
Synchronization.
A process to ensure that operations occur strictly
in order
.
System memory.
The physical memory available to a processor.
Target-disconnect
. The termination of a PCI cycle initiated by the target
because it is unable to respond within eight PCI clock cycles. Note
that the term ‘target-disconnect’ is often used interchangeably with
‘disconnect’.
Tenure
. The period of bus mastership. For the 60x, there can be separate
address bus tenures and data bus tenures. A tenure consists of three
phases—arbitration, transfer, termination.
Throughput
. The measure of the number of instructions that are processed
per clock cycle.
Timeout
. A
transaction termination
due to exceeding a
latency
limit. A
transaction
is not necessarily concluded when a timeout occurs.
Transaction
. A complete exchange between two bus devices. A transaction
is minimally comprised of an address tenure/phase; one or more data
tenures/phases may be involved in the exchange. There are two kinds
of transactions—address/data and address-only.
Transfer termination
. Signal that refers to both signals that acknowledge the
transfer of individual beats (of both single-beat transfer and
individual beats of a burst transfer) and to signals that mark the end
of the tenure/phase.
Word
. A 32-bit data element.
Write-back
.A memory update policy in which processor write cycles are
only required to be written to the
cache
. The data in the cache does
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