Altera Quartus II Scripting - Manual (Page 61)

Chapter 2: Command-line Executables 2–35
quartus_fit
© July 2013 Altera Corporation Quartus II Scripting Reference Manual
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arguments ............................................................................................................................................... 2–93
makefiles.................................................................................................................................................. 2–93
return_codes ........................................................................................................................................... 2–95
--check_ios
Option to run until I/O placement is determined. This process includes placing all blocks in the periphery,
such as PLLs, serializers, deserializers, and gigabit transceiver blocks (GXB).
The report file and the floorplan display I/O placement results. If all pins cannot be placed, the report file
and floorplan display partial placement, results, and error messages to indicate why placement failed.
The "--check_ios" option should not be used when you use the "--io_smart_recompile" option. For
example, after doing a complete place and route, if you change an I/O standard, it is advisable to use the
"--io_smart_recompile" option, because the "--check_ios" option destroys the original place and route
results.
--check_netlist
Option to run only legality checking on the current netlist. Analysis & Synthesis (quartus_map) must be
run successfully before you use this option. Currently changes made to placement or routing are not
verified -- only functional changes (for example, I/O standards) are checked.
This option can be used to verify that the netlist is legal after you make changes using the Chip Editor.
--early_timing_estimate[=<realistic|optimistic|pessimistic>]
Option to run an Early Timing Estimate. An Early Timing Estimate is an estimate of timing results for your
design before performing full placement and routing. This feature runs the fitter up to 10 times faster than
a full fit and generates a full timing report based on estimated delays for the design. The fit is not fully
optimized or routed, and hence the timing report is only an estimate. Typically, the estimated delays are
within 20% of what a full compilation can achieve.
The following table describes the types of timing estimates:
All Early Timing Estimate types have the same reduction of compilation time.
After successfully running "quartus_fit --early_timing_estimate," "quartus_tan --timing_analysis_only"
must be run to generate a timing report.
--effort=<standard|fast|auto>
Option to specify the level of effort you want the Fitter to use.
Value Description
realistic Estimates delays that will likely be close to a full compilation's results. (default value)
optimistic Estimates delays that are lower than those likely to be achieved by a full compilation.
This makes the estimate of performance optimistic.
pessimistic Estimates delays that are higher than those likely to be achieved by a full compilation.
This makes the estimate of performance pessimistic.