mpc823rg Freescale Semiconductor, Inc, mpc823rg Datasheet - Page 1305

• Manufacturer Part Number: mpc823rg
• Description: Mpc823 Powerquicc Integrated Communications Processor For Portable Systems
• Manufacturer: Freescale Semiconductor, Inc

MPC823 Instruction Set—sync
sync
Assembler Syntax
Definition
Description
FIELD
FIELD
BIT
BIT
16
0
17
1
00000
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2
Freescale Semiconductor, Inc.
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For More Information On This Product,
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of all instructions executed by a given processor. Executing a
sync instruction ensures that all instructions preceding the sync
instruction appear to have completed before the sync instruction
completes, and that no subsequent instructions are initiated by
the processor until after the sync instruction completes. When
the sync instruction completes, all external accesses caused by
instructions preceding the sync instruction will have been
performed with respect to all other mechanisms that access
memory.
Multiprocessor implementations also send a sync address-only
broadcast that is useful in some designs. For example, if a
design has an external buffer that reorders loads and stores for
better bus efficiency, the sync broadcast signals to that buffer
that previous loads/stores must be completed before any
following loads/stores. The sync instruction can be used to
ensure that the results of all stores into a data structure, caused
by store instructions executed in a “critical section” of a program,
are seen by other processors before the data structure is seen
as unlocked. The functions performed by the sync instruction
will normally take a significant amount of time to complete, so
indiscriminate use of this instruction may adversely affect
performance. In addition, the time required to execute sync may
vary from one execution to another. The eieio instruction may be
more appropriate than sync for many cases.
sync
Synchronize
The sync instruction provides an ordering function for the effects
POWERPC ARCHITECTURE
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MPC823 REFERENCE MANUAL
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Go to: www.freescale.com
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5
LEVEL
UISA
22
6
23
7
00000
24
8
25
9
SUPERVISOR
598
LEVEL
10
26
11
27
OPTIONAL
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28
00000
13
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MOTOROLA
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FORM
X
15
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0