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Glossary-10
MPC7400 RISC Microprocessor Users Manual
Quiesce
. To come to rest. The processor is said to quiesce when an exception
is taken or a
sync
instruction is executed. The instruction stream is
stopped at the decode stage and executing instructions are allowed to
complete to create a controlled context for instructions that may be
affected by out-of-order, parallel execution..
See
Context
synchronization.
Quiet NaN
. A type of
NaN
that can propagate through most arithmetic
operations without signaling exceptions. A quiet NaN is used to
represent the results of certain invalid operations, such as invalid
arithmetic operations on inTnities or on NaNs, when invalid.
See
Signaling NaN.
rA
. The
r
A instruction Teld is used to specify a GPR to be used as a source
or destination.
rB
. The
r
B instruction Teld is used to specify a GPR to be used as a source.
rD
. The
r
D instruction Teld is used to specify a GPR to be used as a
destination.
rS
. The
r
S instruction Teld is used to specify a GPR to be used as a source.
Real address mode
. An MMU mode when no address translation is
performed and the
effective address
speciTed is the same as the
physical address. The processors MMU is operating in real address
mode if its ability to perform address translation has been disabled
through the MSR registers IR and/or DR bits.
Record bit
. Bit 31 (or the Rc bit) in the instruction encoding. When it is set,
updates the condition register (CR) to reect the result of the
operation.
Referenced bit
. One of two
page history bits
found in each
page table entry
(PTE). The processor sets the
referenced bit
whenever the page is
accessed for a read or write. See also Page access history bits.
Register indirect addressing
. A form of addressing that speciTes one GPR
that contains the address for the load or store.
Register indirect with immediate index addressing
. A form of addressing
that speciTes an immediate value to be added to the contents of a
speciTed GPR to form the target address for the load or store.
Q
R