TMS320F28335: receive fifo, SCI, f28335

Akhil Pillai

Hello,

I wanted to ask what happens if i set my fifo size to 5 and I send something more than 5 bytes. Let's say I send 7 bytes, so my question is, Will the remaining 2 bytes get lost?

Any help is greatly appreciated

Thank you

Akhil

over 8 years ago

0 Kevin Allen18 over 8 years ago

TI__Mastermind 45606 points

Hi Akhil,

The SCI FIFO buffers for this device are non-configurable, where the size of the buffer cannot be changed. Both the TX and RX buffers are set at 16 words.

If you were to have a case where the SCI RX fifo buffer is already full and receive another word, then the new word will overwrite the oldest word in the fifo buffer. This will continue to happen for every new word that is received while the fifo buffer is full.

An Interrupt can be triggered to read from, or empty, the RX fifo buffer when it contains a certain number of words. The desired number of words would be set in the SCIFFRX.RXFFIL register.

Hope this helps,
Kevin

0 Akhil Pillai over 8 years ago in reply to Kevin Allen18

Intellectual 930 points

Hi kevin,

My apologies. What i meant to ask was what will happen if I set the Fifo interrupt level to 5 and i send 7 bytes? Will the remaining 2 bytes get lost or will it be in the FIFO?

Regards,
Akhil

0 Kevin Allen18 over 8 years ago in reply to Akhil Pillai

TI__Mastermind 45606 points

Hi Akhil,

The two extra bytes (or words) will be in the FIFO buffer. If you would like to check that the extra words were written to the RX buffer before the interrupt is serviced you should read the SCIFFRX.RXFFST register flag and then remove that many words from the fifo.

Hope this helps,
Kevin

0 Cody Watkins over 8 years ago in reply to Kevin Allen18

TI__Mastermind 42195 points

Akhil,
I will be closing this thread. If you have any additional questions please start another thread.

Regards,
Cody

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TMS320F28335: receive fifo, SCI, f28335