MCAN_TXFQS

MCAN Tx FIFO/Queue Status

The Tx FIFO/Queue status is related to the pending Tx requests listed in register MCAN_TXBRP. Therefore the effect of Add/Cancellation requests may be delayed due to a running Tx scan (MCAN_TXBRP not yet updated).

In case of mixed configurations where dedicated Tx Buffers are combined with a Tx FIFO or a Tx Queue, the Put and Get Indices indicate the number of the Tx Buffer starting with the first dedicated Tx Buffers.
Example: For a configuration of 12 dedicated Tx Buffers and a Tx FIFO of 20 Buffers a Put Index of 15 points to the fourth buffer of the Tx FIFO.

  0xC4 32 Read-only 0x00000000  

MCAN Tx FIFO/Queue Status

Bit  31 30 29 28 27 26 25 24  
                   
Access                   
Reset                   
Bit  23 22 21 20 19 18 17 16  
      TFQF TFQPI[4:0]  
Access      R R R R R R  
Reset      0 0 0 0 0 0  
Bit  15 14 13 12 11 10 9 8  
        TFGI[4:0]  
Access        R R R R R  
Reset        0 0 0 0 0  
Bit  7 6 5 4 3 2 1 0  
      TFFL[5:0]  
Access      R R R R R R  
Reset      0 0 0 0 0 0  

Bits 5:0 – TFFL[5:0]: Tx FIFO Free Level

Tx FIFO Free Level

Number of consecutive free Tx FIFO elements starting from TFGI, range 0 to 32. Read as zero when Tx Queue operation is configured (MCAN_TXBC.TFQM = ‘1’).

Bits 12:8 – TFGI[4:0]: Tx FIFO Get Index

Tx FIFO Get Index

Tx FIFO read index pointer, range 0 to 31. Read as zero when Tx Queue operation is configured (MCAN_TXBC.TFQM = ‘1’).

Bits 20:16 – TFQPI[4:0]: Tx FIFO/Queue Put Index

Tx FIFO/Queue Put Index

Tx FIFO/Queue write index pointer, range 0 to 31.

Bit 21 – TFQF: Tx FIFO/Queue Full

Tx FIFO/Queue Full

ValueDescription
0

Tx FIFO/Queue not full.

1

Tx FIFO/Queue full.