Altera Quartus II Settings File - Manual (Page 764)

SYNCHRONIZER_IDENTIFICATION
Specifies how the TimeQuest Timing Analyzer identifies registers as being part of a synchronization
register chain for metastability analysis. A synchronization register chain is a sequence of registers with
the same clock with no fan-out in between, which is driven by a pin or logic from another clock domain.
If this option is set to 'Off', the TimeQuest Timing Analyzer does not identify the specified registers, or the
registers within the specified entity, as synchronization registers. If the option is set to 'Auto', the
TimeQuest Timing Analyzer identifies valid synchronization registers that are part of a chain with more
than one register that contains no combinational logic. If this option is set to 'Forced if Asynchronous',
the TimeQuest Timing Analyzer identifies synchronization register chains if the software detects an
asynchronous signal transfer, even if there is combinational logic or only one register in the chain. If this
option is set to 'Forced', then the specified register, or all registers within the specified entity, are identified
as synchronizers. The 'Forced' option should not be applied to the entire design, because doing so
identifies all registers in the design as synchronizers. Registers that are identified as synchronizers are
optimized for improved Mean Time Between Failure (MTBF) as long as the Optimize Design for
Metastability option is turned on. If a synchronization register chain is identified with the 'Forced' or
'Forced if Asynchronous' option, then the TimeQuest Timing Analyzer reports the metastability MTBF
for the chain. MTBF is not reported for automatically-detected register chains; you can use the 'Auto'
setting to generate a report of possible synchronization chains in your design. If a synchronization register
chain is identified with the 'Forced' or 'Forced if Asynchronous' option, then the TimeQuest Timing
Analyzer reports the metastability MTBF for the chain when it meets the design timing requirements.
Old Name
ANALYZE_METASTABILITY
Type
Enumeration
Values
• Auto
• Forced
• Forced If Asynchronous
• Off
Device Support
This setting can be used in projects targeting any Altera device family.
Notes
This assignment supports wildcards.
This assignment supports Fitter wildcards.
This assignment is included in the Fitter report.
Syntax
set_global_assignment -name SYNCHRONIZER_IDENTIFICATION <value>
set_global_assignment -name SYNCHRONIZER_IDENTIFICATION -entity <entity
764 SYNCHRONIZER_IDENTIFICATION
MNL-Q21005
2015.05.04
Altera Corporation Quartus Settings File Reference Manual
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