RM48L952: [FAQ] Problems when transmitting more than 64K Byte data in DMA applied SCI communication

영호 안

Part Number: RM48L952

Hello, thank you for always answering my questions.
Today, I discovered a problem while trying to transmit 71K Byte of data in multi-buffer mode SCI communication with DMA.
While looking for a problem because all data was not transmitted, we confirmed that data less than 64K Byte is completely transmitted, but when more than 64K Byte is transmitted, the total data minus 64K Byte is transmitted.
I couldn't find the cause of this in the data sheet nor in the forum, so I'm asking this question.
What could be causing this and how can I fix it?
Thank you for your time. Below is my code file.

20220907_BigEndian_Test.zip

over 2 years ago

0 jagadish gundavarapu over 2 years ago

TI__Guru 69891 points

Hi,

I started working on your issue and i will get back to you soon with the solution.

Thanks & Regards,

Jagadish.

+1 jagadish gundavarapu over 2 years ago in reply to jagadish gundavarapu

TI__Guru 69891 points

Hi,

The maximum number of frames you can transfer using the DMA for one block transfer is 0x1FFF (i.e. decimal 8191)

So even if you configure more frames than 8191 you can only send 8191 frames only, in our example single frame consists of 8 bytes so we can send max of 65528 bytes(~64kb). If you want to transmit more than 8191 frames then please reconfigure DMA with remaining frames(Total-8191) after sending 8191 frames.

Thanks & Regards,

Jagadish.

Arm-based microcontrollers

Arm-based microcontrollers forum

RM48L952: [FAQ] Problems when transmitting more than 64K Byte data in DMA applied SCI communication