On 21.02.2022 14:43:57, Srinivas Neeli wrote: > > Can you also provide the hand calculated bit timing parameters for > > the above scenarios? > > Baud rate 1/5Mbps > ================ > > Hand configuration: > --------------------------- > ip link set can0 type can tq 12 prop-seg 29 phase-seg1 30 phase-seg2 20 sjw 1 dtq 12 dprop-seg 5 dphase-seg1 6 dphase-seg2 4 dsjw 1 fd on (A/D: 1/5Mbps, Sample point=75%) > > Baud rate 1/4Mbps > ================ > > Hand configuration: > -------------------------- > ip link set can0 type can tq 12 prop-seg 29 phase-seg1 30 phase-seg2 20 sjw 1 dtq 12 dprop-seg 7 dphase-seg1 7 dphase-seg2 5 dsjw 1 fd on (A/D: 1/4Mbps, Sample point=75%) I've updated the algorithm to prefer lower brp values. Can you check if these values make sense to you? | $ ./can-calc-bit-timing --alg=can-next xilinx_dwnstrm -c 79999999 | Bit timing parameters for xilinx_dwnstrm with 79.999999 MHz ref clock (cmd-line) using algo 'can-next' | nominal real Bitrt nom real SampP | Bitrate TQ[ns] PrS PhS1 PhS2 SJW BRP Bitrate Error SampP SampP Error | 1000000 12 29 30 20 1 1 999999 0.0% 75.0% 75.0% 0.0% | 800000 12 39 40 20 1 1 799999 0.0% 80.0% 80.0% 0.0% | 666666 12 47 48 24 1 1 666666 0.0% 80.0% 80.0% 0.0% | 500000 12 69 70 20 1 1 499999 0.0% 87.5% 87.5% 0.0% | 250000 25 69 70 20 1 2 249999 0.0% 87.5% 87.5% 0.0% | 125000 50 69 70 20 1 4 124999 0.0% 87.5% 87.5% 0.0% | 100000 50 87 87 25 1 4 99999 0.0% 87.5% 87.5% 0.0% | 83333 50 104 105 30 1 4 83333 0.0% 87.5% 87.5% 0.0% | 50000 100 87 87 25 1 8 49999 0.0% 87.5% 87.5% 0.0% | 33333 125 104 105 30 1 10 33333 0.0% 87.5% 87.5% 0.0% | 20000 250 87 87 25 1 20 19999 0.0% 87.5% 87.5% 0.0% | 10000 500 87 87 25 1 40 9999 0.0% 87.5% 87.5% 0.0% | | Bit timing parameters for xilinx_dwnstrm with 79.999999 MHz ref clock (cmd-line) using algo 'can-next' | nominal real Bitrt nom real SampP | Bitrate TQ[ns] PrS PhS1 PhS2 SJW BRP Bitrate Error SampP SampP Error | 12000000 12 2 2 2 1 1 11428571 4.8% 75.0% 71.4% 4.8% | 10000000 12 2 3 2 1 1 9999999 0.0% 75.0% 75.0% 0.0% | 8000000 12 3 3 3 1 1 7999999 0.0% 75.0% 70.0% 6.7% | 5000000 12 5 6 4 1 1 4999999 0.0% 75.0% 75.0% 0.0% | 4000000 12 7 7 5 1 1 3999999 0.0% 75.0% 75.0% 0.0% | 2000000 12 14 15 10 1 1 1999999 0.0% 75.0% 75.0% 0.0% | 1000000 25 14 15 10 1 2 999999 0.0% 75.0% 75.0% 0.0% regards, Marc -- Pengutronix e.K. | Marc Kleine-Budde | Embedded Linux | https://www.pengutronix.de | Vertretung West/Dortmund | Phone: +49-231-2826-924 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 |
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