MC56F82748 CAN information

[EngHuiPeng]

Customer is checking whether MC56F82748 CAN feature is able to do sample point between 80-84. 

Customer requirement is as follow

CAN baud rate: 500K

Sample point: 80-84

Sync Jump width 2-4

I see in the DSC56800EXQSUG that the MSCAN can set the Sample point and Synch Jump width. How to calculate the sample point as the sample selection is 1 sample/bit to 3 samples/bit. Can MC56F82748 meet the above criteria. 

Thanks.

Regards,

Audrey

[xiangjun_rong]

Hi, Audrey,

Regarding your question, for MC56F82748, the bus clock is 50MHz, the CAN baudrate is 0.5MHz, the divider is 50MHz/0.5MHz=100, if you set the prescaler as 2(seting BRP bits in CAN_BTR0 as 1), the Tq clock cycle in ONE CAN bit is 25. In the case, for RX pin, the sampling point ocurs at the end of Time segment1, if you set the SAMP in CAN_BTR1, the CAN will sample the logic of RX pin at the end of Time Segment1 three times, the resulting bit value is determined by using majority rule on the three total samples.

Hope it can help you

BR

Xiangjun Rong