CAN Rx FIFO Mail Boxes

[Nico3]

Hello

I have a query regarding mailboxes for receiving FIFO in CAN peripheral. The manual says there are two FIFOs and each FIFO has three mailboxes. So, it means there should be total SIX registers for receiving DATA. But I see only two registers CAN_RDX0R   & CAN_RDX1R. 

Please correct me.

PS: Manual says there are three mailboxes for Tx and I see three registers CAN_TDX0R, CAN_TDX1R & CAN_TDX2R.