
Glossary-2
MPC106 PCIB/MC User's Manual
MOTOROLA
Burst
. A multiple beat data transfer whose total size is typically equal to a
cache line (32-bytes).
Bus clock
. Clock that synchronizes the bus state transitions.
Bus master
. The owner of the address or data bus; the device that initiates or
requests the transaction.
Cache
. High-speed memory containing recently accessed data and/or
instructions (subset of main memory).
Cache flush
. An operation that removes from a cache any data from a
specified address range. This operation ensures that any modified
data within the specified address range is written back to main
memory. This operation is generated typically by a Data Cache
Block Flush (
dcbf
) instruction.
Caching-inhibited
. A memory update policy in which the
cache
is bypassed
and the load or store is performed to or from main memory.
Cache line
. A small region of contiguous memory that is copied from
memory into a
cache
. The size of a cache line may vary among
processors; the maximum block size is one
page
. Note that the term
‘cache line’ is often used interchangeably with ‘cache block’.
Cast-outs
.
Cache line
that must be written to memory when a snoop miss
causes the least recently used cache line with modified data to be
replaced.
Clear
. To cause a bit or bit field to register a value of zero.
See also
Set.
Copy-back operation
. A cache operation in which a cache line is copied
back to memory. Copy-back operations consist of
snoop push-out
operations and cache
cast-out
operations.
Direct-store
. Interface available on PowerPC processors only to support
direct-store devices from the POWER architecture.
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
‘disconnect’ is often used interchangeably with ‘target-disconnect’.
E
xception
. An unusual or error condition encountered by the processor that
results in special processing.
C
D
E