JavierHormigo
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Re: Strange behavior of Quartus Fitter and how to get more information
Hi @BoonBengT_Altera , I checked the "place" report, and I could see significant differences but I don't understand many terms such as [B]Estimate of ALMs recoverable by dense packing [C][b] Due to LAB-wide signal conflicts LAB logic registers: Secondary logic registers Could you clarify them? Besides that, I have no idea of how I can influence on the value of these parameters. Thank you, JAvierRe: Strange behavior of Quartus Fitter and how to get more information
Hi @BoonBengT_Altera I have been going through the files you suggested but I still don't understand why a design that occupies significantly fewer resources fails to be fitted while the original implement with no errors. The report only said that there are not enough LABs in the region, but why? Is it because the Quartus estimation is so wrong that instead of reducing the resources by 30% as it said, they actually grow? Is it because although the resources are less they are concentrated in the same region? If so, why? I have not changed anything to force the tool to put everything in the same region, why don't use a different region? How can I handle this situation? Too many questions raised. Thanks, JAvierRe: Strange behavior of Quartus Fitter and how to get more information
Hi @BoonBengT_Altera , Sorry, I exaggerated the reduction achieved by the new version of the 12 kernels. It wasn't 40 %. The detailed reduction is ALUT 25% REG 33% MLAB 20% RAM 35% which still are very significant. You can extract those figures from the tables I sent on October 10th. Attached you can find the rpt files regarding the fitter for the initial successful implementation and for the second that fails. I hope those files can help to understand what is happening. Thanks, JAvierRe: Strange behavior of Quartus Fitter and how to get more information
Hi @BoonBengT_Altera, I did what you suggested and that lead us to my first question: Using the 12 kernel as a baseline, the estimation report said the new version uses around 40% fewer resources. However, the fitter fails to implement the hardware because of a lack of enough LABs. How is this possible? How could I get more information about the fitter process? Thanks, JAvierRe: Strange behavior of Quartus Fitter and how to get more information
Hi @BoonBengT_Altera All these detailed reports are "estimated resource utilization" reports. In all this report the new architecture uses much less area than the original one. However, when implemented, the fitter fails. So, there are no useful information on this problem in those report. I need a report on the fitting process to see what's going on or any inside why the estimate said the area is reduced when the fitter said it grows. ThanksRe: Strange behavior of Quartus Fitter and how to get more information
The initial report with 12 kernels are: Device Static partition Quartus Fitter: Total Used (Entire System) Quartus Fitter: Kernel System Estimated: Kernel system ALM 702720 168990 645,368 415228.0 - ALUT 553419 - REG 2810880 675960 1,392,304 1022779 944410 - MLAB 3233 4068 RAM 6847 1590 3,867 2599 2147 DSP 3960 786 144 144 144 After optimizing the kernels using the simplest LSU (FIFO) and [[intel::max_global_work_dim(0)]] in functions to eliminate the function overhead, the report for 12 kernels is the one below Device Static partition Quartus Fitter: Total Used (Entire System) Estimated: Kernel system ALM 702720 168990 TBD - ALUT 420411 - REG 2810880 675960 TBD 636982 - MLAB 3288 RAM 6847 1590 TBD 1403 DSP 3960 786 TBD 144 The estimated utilization is much lower but the implementation finished with the error similar to that: "Error (170012): Fitter requires 72611 LABs to implement the design, but the device contains only 66099 LABs." This error is not consistent because sometimes it says more LAB are needed for smaller designs and also the number of LAB the device contains changes. I'm not sure If I know where should I get the the resource map. Thanks.
