AM6442: UART with DMA. How to enable UART RX with variable length

Alan Ismail

Part Number: AM6442

Tool/software:

Dear Experts

The requirement is for r5f core in am6442 to use UART+DMA RX to receive transmissions with frame length of 20-110(variable )bytes, There is no indication of next frame length would be so the UART+DMA has to detect end of frame and issue interrupt to user

Data is expected to arrive every 4ms.

Is it possible to achieve this configuration with AM6442 , r5f + UART + DMA in non blocking mode.

Thank you

Alan I

27 days ago

0 Vaibhav Kumar 22 days ago

TI__Mastermind 45316 points

Hi Alan,

Let me know if a combination of DM Timers and UART would work for you?

The timer can generate an interrupt every 4 ms and UART can then go ahead and receive the transmission.

Best,

Vaibhav

0 Alan Ismail 22 days ago in reply to Vaibhav Kumar

Intellectual 385 points

Hi Vaibhav.

Is DM Timers refer to Dual Mode Timer?

Yes DM Timers can initiate the receive. Since the packet size is variable. I am not clear on how to get DMA to issue interrupt at the end of receive with variable length

To add to the complexity, there is no synchronization and phase lock between 4ms Time on am6442 to ~4ms on the transmitter side. In this scenario, the packet can be seen as "slowly driting" from receiver perspective.

Thanks

Alan I

0 Vaibhav Kumar 19 days ago in reply to Alan Ismail

TI__Mastermind 45316 points

Hi Alan,

Alan Ismail said:
Since the packet size is variable.

Please give a read through the following E2E: e2e.ti.com/.../5999396

Thanks,

Vaibhav

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AM6442: UART with DMA. How to enable UART RX with variable length