STM32F091RC=please tell me detailed procedure for can bit time calculation,to find value of these hcan.Instance = hcan.Init.Prescaler = hcan.Init.SyncJumpWidth = hcan.Init.TimeSeg1 = hcan.Init.TimeSeg2 =

[Wilson]

..

[Tesla DeLorean]

CAN BIT RATE = (APBCLOCK / PRESCALER) / (SJW + TS1 + TS2)

[Wilson]

can u explain each terms?

[Tesla DeLorean]

I'm sure the definitions are in the Reference Manual

SJW, TS1 and TS2 are the bit timing quanta, they have ranges as described in the manual. You sum these together to understand how many clock ticks you will need.

The CAN peripheral is clocked by the APB (Peripheral Bus) to which it is attached. Presumably 48 or 24 MHz depending on the dividers you have selected.

48,000,000 / 50,000 = 960

960 / 60 = 16

If you set the Prescaler to 60, the sum of SJW+TS1+TS2 needs to be 16, find a combination that fits.. Say 1, 7 and 8 ?

[Wilson]

at 48 mhz clock frequency,baudrate=50 kbps

[Wilson]

ok

[Wilson]

how did you choose 1,7,8?

sjw=1,ts1=7,ts2=8?

[turboscrew]

https://www.nxp.com/docs/en/reference-manual/BCANPSV2.pdf

Ch 6 or ch 13.

[waclawek.jan]

[OT] It's nice how in explanation of a ST's chip you refer to a document to be found at NXP, which refers to "Motorola CAN" in a Freescale chip... ;)

(Sorry for the OT, I couldn't resist. No, no need to explain.)

JW

[turboscrew]

BTW, the time quanta settings look different from the standard, because the standard says thet the SYNC_SEG is always 1. It doesn't need to be configured. Alsi in STM32 bxCAN, the TimeSeg1 contains the sum of both PROP_SEG and PHASE_SEG1.

And no, there is no "Motorola CAN", "Intel CAN" or "STMicro CAN". Just CAN.