Forum Discussion
Altera_Forum
Honored Contributor
18 years agoMaik,
To use a larger device try the StratixIII family. The free version of the tools supports some smaller members of the high-end families, but even those smallest members are larger than your baseline part. The EP3SL70, for instance, is roughly 7x your EP1S10. Details on what is supported in the web version are at http://www.altera.com/products/software/products/quartus2web/features/sof-quarweb_features.html. Regarding differences between software releases it is not necessarily that the default settings have changed but rather that the optimization, placement, and routing algorithms have changed. Thus you will see different results between different versions. In general you make adjustments to the settings to match or beat what an older release achieved. As an example one change between 4.1 and 7.1 was power optimization. Traditionally the tradeoff has been timing versus resources; now power dissipation is also considered when performing tradeoffs to find a "best fit" implementation. The PowerPlay power optimizations are on by default, and this will potentially increase logic usage or degrade timing to improve power dissipation. So after importing from 4.1 to 7.1 SP1 you would need to turn off power optimizations if you care about resources and/or timing more than power (see "Assignments / Settings / Analysis & Synthesis Settings / Powerplay power optimizations"). There is an option for Powerplay optimizations under the fitter settings also, but this impacts compilation time and timing more than resources. Since the number of assignments and settings can be overwhelming, Altera has added advisors into the tool to provide guidance. Have you tried the Resource Optimization Advisor in version 7.1 (under "Tools / Advisors")? This will provide guidance on how to improve resource utilization. For instance to reduce LE usage expand the category "Logic Element Usage" then view the three stages: Stage 1 is basic advise that should be followed first, stage 2 is the next level and may provide some additional savings, and stage 3 is the final step which may provide some additional reductions but can potentially impact other areas.