DCAN + DMA with RM48L952

Boris Georgiev

Hello Support,

I managed to do transfer between RAM to RAM with DMA. Next step was to try to run DCAN whit DMA, but I'm not sure is it possible ? How to initialize source address because, DCAN have two registers (Data A and Data B Registers) which must refer ?

Thank You.
Regards
Boris

over 13 years ago

0 Zhaohong Zhang over 13 years ago

TI__Mastermind 22715 points

Boris,

I would not consider that there are much advantage in using DMA with DCAN. On DCAN, CPU (or DMA if you want to use it) access the DCAN mailboxes in DCAN RAM via interface registers. Data registers A and B are only two of them. You need to first set up all other registers for the operation and then write to the byte of mailbox number in the IF mask/command register to trigger the transfer. Please refer to the DCAN spec for more details.

Thanks and regards,

Zhaohong

0 Boris Georgiev over 13 years ago in reply to Zhaohong Zhang

Prodigy 30 points

Thank you Zhaohong,

Otherwise, the standard way to transfer (transmit and receive) success without DMA. My idea now is to receive only a packets via CAN with DMA for more performance, but transmit without using of DMA.

Regards,

Boris.

0 Zhaohong Zhang over 13 years ago in reply to Boris Georgiev

TI__Mastermind 22715 points

Boris,

For accessing the DCAN mailboxes, reading is similar to writing. You will need to poll a status bit to check the data is returned to data registers from DCAN RAM. therefore, I do not think that DMA would provide any advantage.

Thanks and regards,

Zhaohong

0 Boris Georgiev over 13 years ago in reply to Zhaohong Zhang

Prodigy 30 points

Тhanks for the help I think I managed to solve the problem.

Thanks

and regards,

Boris.

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DCAN + DMA with RM48L952