Achronix ACE Version 5.0 User Manual
Page 238
Projects
Chapter 3. Concepts
Option Sets only enable performance-related implementation options, and (currently) never disable any
already-enabled implementation options. So each generated implementation starts with the exact same
implementation options as the template implementation, and then just the few implementation options
named in the Option Set’s description are overwritten with the described values.
Achronix broke up the Option Sets into small granular chunks because of QOR/runtime tradeoffs. Some
of the options have a large runtime cost, and on some designs there is a minimal performance gain. Based
upon the observed runtimes reported in the
, users may choose to save hours
of runtime if they only lose 0.01% frequency by using (for example) the Option Set ”acx util pro” instead of
”acx all opt” as they iterate their design. (Many of the Option Sets like ”acx util pro” will enable a subset
of what ”acx all opt” enables.)
Note:
Currently, the Option Set overrides will only enable optimization-oriented
implementation options, not disable them. Thus, if the implementation options in the
template implementation are already the same values as those in the Option Set, the
results from the two implementations (the implementation generated from the Option Set,
and the template implementation) will be identical.
It is expected that among all the Option Sets, users will be able to find at least one that provides the necessary
QOR gain for an acceptable runtime impact, allowing the user the fastest possible design iteration.
See the
and
Attempting Likely Optimizations Using Option Sets
for more info.
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