How to use register to set Flexcan for judge mailbox whether is busy or idle on S32K144

[jinshuaixu]

Hello to everybody:

        Now, l want to judge whether mailbox 6 is idle or busy,l use library function just as below ago:

if (FLEXCAN_DRV_GetTransferStatus(INST_CANCOM1, TX_MAILBOX_6) != STATUS_BUSY) {

    //do something
 }

     if l want to use register just as "if((CAN0->IFLAG1)&0x00200000)". who can give me some advise,thank you for your helping.