Altera Quartus II Settings File - Manual (Page 586)

GUARANTEE_MIN_DELAY_CORNER_IO_ZERO_HOLD_TIME
Controls whether the fitter tries to achieve a zero hold time for I/O pins that feed globally clocked
registers at the fast corner and in stringent operating conditions even if a design does not contain timing
assignments. When this option is set to On, the fitter preserves zero hold time for I/O pins feeding
globally clocked registers at the fast corner and in stringent operating conditions. This setting may cause
violations of tSU or tPD timing constraints. When this option is set to Off, the fitter optimizes a design to
meet user timing assignments only. When this option is set to 'When Tsu and Tpd Constraints Permit',
the fitter preserves zero hold time for I/O pins feeding globally clocked registers at the fast corner and in
stringent operating conditions only if this can be done without violating tSU or tPD timing constraints.
This option is useful for automatically meeting I/O hold time requirements in the fast corner without
specifying any extra timing constraints.
Type
Enumeration
Values
• Off
• On
• When Tsu and Tpd Constraints Permit
Device Support
This setting can be used in projects targeting any Altera device family.
Notes
This assignment is included in the Fitter report.
Syntax
set_global_assignment -name GUARANTEE_MIN_DELAY_CORNER_IO_ZERO_HOLD_TIME
Default Value
On
586 GUARANTEE_MIN_DELAY_CORNER_IO_ZERO_HOLD_TIME
MNL-Q21005
2015.05.04
Altera Corporation Quartus Settings File Reference Manual
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