TMS320F28388D: MCAN

Jammy Feng

Prodigy 60 points

Part Number: TMS320F28388D

Hi,

TMS320F28388D As per TMS320F2838x TRM section 45.5.14 Figure 45-13

msgRAMConfigParams.txFIFOSize = 7U; // Tx FIFO/Queue.

Now if put index =7, and get index =2, then call

MCAN_writeMsgRam(MCAN0_BASE, MCAN_MEM_TYPE_FIFO,0U, &txMsg);

//
        // Enable Transmission interrupt.
        //
        MCAN_txBufTransIntrEnable(MCAN0_BASE, fifoStatus.putIdx,1U);

        //
        // Add request for transmission.
        //
        MCAN_txBufAddReq(MCAN0_BASE, fifoStatus.putIdx);


after that ,I want to kown if the put index = 0 ?  In other words, Is the FIFo circle FIFO?

over 4 years ago

0 Praveen Kumar Ravichandran over 4 years ago

TI__Expert 4610 points

Hi,

Yes, it is a circular FIFO and once the get index reaches the end of the FIFO, any new writes will be written into index = 0.

Please note that the index starts from 0 and not 1

Regards,
Praveen

0 Jammy Feng over 4 years ago in reply to Praveen Kumar Ravichandran

Prodigy 60 points

Hi,

I am not clear about :

1)when using TX FIFO,host had trasmitted a message, Is the TX get index plus 1? If yes,why don't I see SW do this?

2)When using RX FIFO,host had received a message,Is the RX put index plus 1? If yes,why don't I see SW do this?

0 Praveen Kumar Ravichandran over 4 years ago in reply to Jammy Feng

TI__Expert 4610 points

Hi,

Can you please clarify on what do you mean by 'Why dont I see SW do this?' Are you trying to understand why the SW is not incrementing the index? The different indexes are controlled by the HW and are read-only for SW.

Regards,
Praveen

0 Jammy Feng over 4 years ago in reply to Praveen Kumar Ravichandran

Prodigy 60 points

Hi,

Yes.I mean why SW not chang the get index or the put index when TX buffer trasmit a message or Rx buffer receive a message.

The different indexes are controlled by the HW.How can I read the get index or the put index when TX buffer trasmit a message or Rx buffer receive a message ?

+1 Praveen Kumar Ravichandran over 4 years ago in reply to Jammy Feng

TI__Expert 4610 points

Jammy,

The get index and put index for TX/RX are available in their respective status registers(MCAN_TXFQS, MCAN_RXFxS). Any point of time, these values can be read by the SW to know the current index.

Regards,
Praveen

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TMS320F28388D: MCAN