topic SKEAZ64 CAN in Kinetis Microcontrollers

SKEAZ64 CAN

suntaoisme — Tue, 13 May 2025 03:26:11 GMT

I'm using the SKEAZ64MLH4 for 500kbit/s CAN communication. The configuration sampling point is only up to 80% and the my customer needs a sampling point greater than 85%, Please kindy assist in confirming if there is a feasible configuration?

Re: SKEAZ64 CAN

Celeste_Liu — Thu, 15 May 2025 10:50:17 GMT

Hello @suntaoisme ,

Thanks for your post.

sample point= (1+TSEG1)/(1+TSEG1+TSEG2), So, according to your configuration, the sample point is calculated as follows:

sample point = (1+ 7) /(1+7+2) = 80%

If you want to achieve a sample point greater than 85%, you need to increase TSEG1. For example, if TSEG1 is increased to 13, the sample point can reach 87.5%.

Hope it can help you.

BRs,

Celeste

Re: SKEAZ64 CAN

RalphLIU — Fri, 16 May 2025 14:13:03 GMT

Dear Celeste,

thanks for your support, but if only improve Time SEG1, is there some way to guarantee 500K bit rate?

Re: SKEAZ64 CAN

suntaoisme — Sat, 17 May 2025 00:51:43 GMT

Thanks for your reply. Would modifying T1 alone be ineffective, and would it provide a solution to validate that it works? Thanks.

Re: SKEAZ64 CAN

Celeste_Liu — Mon, 19 May 2025 07:36:41 GMT

Hello @suntaoisme ,

I'm curious about which IDE you used for the configuration page. I'm using Processor Expert in CodeWarrior v11.1 for configuration, and the interface seems different from yours.

Moreover, we have the CAN timing calculator that refers to AN1798(AN1798: CAN Bit Timing Requirements) to set the communication speed and then calculates all the necessary timing parameters.

I think there is no issue with the MSCAN configuration in Processor Expert (PE) of CodeWarrior v11.1. You can use this tool to derive all the appropriate parameters.

BRs,

Celeste

Re: SKEAZ64 CAN

suntaoisme — Wed, 21 May 2025 00:55:46 GMT

Hi Celeste Liu,

It's my CW version.

T1=5, T2=8, sampling point =42% ，and 499.332 Kbit/S is not 500Kbit/S by the customer。

Do you have a better idea of the correct combination of parameters? Thanks.

Re: SKEAZ64 CAN

Celeste_Liu — Mon, 26 May 2025 07:25:55 GMT

Hello @suntaoisme ,

Thanks for your reply.

You can refer to the following configuration, use the external clock with 10MHz, and let TSG1=16, TSG2=3, then the speed can be 500kbit/s and sampling point = 85%.

BRs,

Celeste