| *** tpb has joined #yosys | 00:00 | |
| *** lutsabound has quit IRC | 00:23 | |
| *** pie__ has quit IRC | 00:27 | |
| *** pie__ has joined #yosys | 00:27 | |
| *** kraiskil has joined #yosys | 00:34 | |
| *** kraiskil has quit IRC | 01:24 | |
| *** develonepi3 has quit IRC | 02:44 | |
| *** kraiskil has joined #yosys | 04:42 | |
| *** kraiskil has quit IRC | 04:55 | |
| *** dpzmick_ has joined #yosys | 05:37 | |
| *** _whitelogger has quit IRC | 05:42 | |
| *** _whitelogger has joined #yosys | 05:44 | |
| *** dpzmick_ has quit IRC | 06:03 | |
| *** rohitksingh has joined #yosys | 08:04 | |
| *** TFKyle has quit IRC | 08:05 | |
| *** rohitksingh has quit IRC | 08:12 | |
| *** rohitksingh_ has joined #yosys | 08:13 | |
| *** rohitksingh_ has quit IRC | 08:17 | |
| *** rohitksingh has joined #yosys | 08:19 | |
| *** rohitksingh has quit IRC | 08:25 | |
| *** rohitksingh has joined #yosys | 08:26 | |
| *** rohitksingh has quit IRC | 08:34 | |
| *** rohitksingh has joined #yosys | 08:44 | |
| *** rohitksingh has quit IRC | 09:01 | |
| *** rohitksingh has joined #yosys | 09:02 | |
| *** rohitksingh has quit IRC | 09:31 | |
| *** rohitksingh has joined #yosys | 09:33 | |
| *** rohitksingh has quit IRC | 10:08 | |
| *** rohitksingh has joined #yosys | 10:08 | |
| *** rohitksingh has quit IRC | 10:35 | |
| *** zkms has quit IRC | 10:53 | |
| *** zkms has joined #yosys | 10:56 | |
| *** pie___ has joined #yosys | 11:11 | |
| *** pie__ has quit IRC | 11:14 | |
| *** maikmerten has joined #yosys | 13:40 | |
| maikmerten | I have a question regarding the "est tns" output of nextpnr. For my design, the output startes highly negative, then creeps towards zero | 13:47 |
|---|---|---|
| maikmerten | Info: at iteration #1: temp = 10000.000000, cost = 112265, est tns = -2366.69ns | 13:47 |
| maikmerten | ... | 13:47 |
| maikmerten | Info: at iteration #365: temp = 0.000001, cost = 9392, est tns = -0.96ns | 13:48 |
| maikmerten | so is that the timing slack, with negative numbers meaning the timing target is not yet reached? | 13:48 |
| daveshah | maikmerten: this is a very rough estimate of timing used by the placer | 13:49 |
| daveshah | it's primarly there fore placer debugging than as a real indicator as to whether the design will pass timing after routing | 13:49 |
| maikmerten | ah, thanks | 13:50 |
| daveshah | it is the sum of all the estimated (budget - actual slack | 13:50 |
| daveshah | *actual delay) | 13:50 |
| daveshah | when that value is negative | 13:50 |
| maikmerten | I noticed that with low values of --slack_redist_iter it appears to creep faster towards zero | 13:50 |
| daveshah | That is also because slack_redist_iter will redistribute the budget | 13:52 |
| daveshah | So it will allow a higher amount of delay in the slower parts of the paths | 13:52 |
| maikmerten | so that's not simply a "try harder" button that trades of computational effort and quality | 13:53 |
| maikmerten | so, in the end the routing ending up with | 14:21 |
| maikmerten | Info: at iteration #385: temp = 0.000000, cost = 11258, est tns = -114.20ns | 14:21 |
| maikmerten | Info: at iteration #386: temp = 0.000000, cost = 11258.000000 | 14:21 |
| maikmerten | is not troublesome, because that's basically a preliminary estimate | 14:22 |
| maikmerten | with | 14:22 |
| maikmerten | Info: Max frequency for clock 'uart_inst.CLK_I_$glb_clk': 29.83 MHz (PASS at 28.00 MHz) | 14:22 |
| maikmerten | being the real deal | 14:22 |
| daveshah | Yes, that is correct | 14:23 |
| maikmerten | cool, thanks again for taking the time to answer my somewhat basic questions! | 14:25 |
| *** lutsabound has joined #yosys | 14:41 | |
| *** pie__ has joined #yosys | 14:57 | |
| *** pie___ has quit IRC | 15:01 | |
| *** rohitksingh has joined #yosys | 15:03 | |
| *** maikmerten has quit IRC | 15:25 | |
| *** tautologico has quit IRC | 15:30 | |
| *** voxadam has quit IRC | 16:11 | |
| *** leviathanch has joined #yosys | 16:36 | |
| *** _whitelogger has quit IRC | 16:54 | |
| *** _whitelogger has joined #yosys | 16:56 | |
| *** kraiskil has joined #yosys | 16:59 | |
| *** tautologico has joined #yosys | 17:05 | |
| *** rohitksingh has quit IRC | 17:22 | |
| *** TFKyle has joined #yosys | 17:30 | |
| *** leviathanch has quit IRC | 17:30 | |
| *** seldridge has joined #yosys | 18:16 | |
| *** emeb has joined #yosys | 18:19 | |
| *** pie___ has joined #yosys | 18:44 | |
| *** pie__ has quit IRC | 18:44 | |
| *** kraiskil has quit IRC | 19:03 | |
| *** rohitksingh has joined #yosys | 19:09 | |
| *** tautologico has quit IRC | 19:14 | |
| *** rohitksingh has quit IRC | 20:16 | |
| *** lutsabound has quit IRC | 21:10 | |
| *** AlexDaniel has joined #yosys | 21:17 | |
| *** seldridge has quit IRC | 22:00 | |
Generated by irclog2html.py 2.13.1 by Marius Gedminas - find it at mg.pov.lt!