Altera FPGA users need no introduction to Partition Merge, a step in the Altera Quartus-II (\"Quartus\") design compilation process that combines multiple netlists (post-synthesis or post-fit) into a single, complete netlist. Quartus triggers this step automatically whenever it detects any design partitions in a project.<\/p>\n
Will Quartus always run Partition Merge? If not, why?<\/b><\/span> For example, if you import a Quartus Exported Partition File (.qxp file) into your project and designate it as a partition, Quartus will run Partition Merge during the compilation process. Okay, so what?<\/b> Table 1: Timing results with and without Partition Merge<\/p>\n Intuitively, the above results seem logical because Partition Merge performs optimizations such as resource sharing, thus affecting timing performance. The \"gotcha\"<\/i> here is that one might think that importing a netlist automatically triggers Partition Merge, but no -- you would have to explicitly declare it as a partition before things work as expected.<\/p>\n How we found this 'bug' was actually rather interesting -- InTime exported a result for a customer and the customer proceeded to reproduce the same result in Quartus, but obtained a much worse result (exactly what you see in Table 1 above). After banging our heads against the wall for a couple of days, we finally found the cause of the differences and documented it here in case someone else runs into a similar predicament.<\/p>\n Altera FPGA users need no introduction to Partition Merge, a step in the Altera Quartus-II (“Quartus”) design compilation process that combines multiple netlists (post-synthesis or post-fit) into a single, complete netlist. Quartus triggers this step automatically whenever it detects any design partitions in a project. Will Quartus always run Partition Merge? If not, why? Quartus […]<\/p>\n","protected":false},"author":6,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"spay_email":"","jetpack_publicize_message":"","jetpack_is_tweetstorm":false,"_links_to":"","_links_to_target":""},"categories":[206],"tags":[],"yoast_head":"\n
\nQuartus tries to detect partitions in your design and only runs Partition Merge if there is at least one partition.<\/p>\n
\nHowever, if you simply import the same .qxp netlist as a source file but neglect to designate it as a partition, Quartus will NOT run Partition Merge automatically.<\/p>\n
\nWorking with a customer, we found that timing results improved significantly (see Table 1 below) when Partition Merge was run versus when it was not run.<\/p>\n\n\n
\n Arria 10 design<\/span><\/th>\n Without Partition Merge<\/span>
\n(.qxp as source file)<\/span><\/th>\nWith Partition Merge
\n(same .qxp as a partition)<\/span><\/th>\n<\/tr>\n\n \n \n \n \n \n \n \n