One of the interrupt sources is the MRAF (Message
RAM access failure in register IR.MRAF). The flag and interrupt is
set, when the Rx handler:
- Has not completed acceptance filtering, or
storage, of an accepted message until the arbitration field
of the following message has been received. In this case,
acceptance filtering or message storage is aborted and the
Rx handler starts processing the following message.
- Was not able to write a message to the message
RAM. In this case, message storage is aborted. In both
cases, the FIFO put index is not updated respectively, the
new data flag for a dedicated Rx buffer is not set, and a
partly stored message is overwritten when the next message
is stored to this location. The flag is also set when the Tx
handler is not able to read a message from the message RAM
in time. In this case, message transmission is aborted. In
case of a Tx handler access failure, the M_CAN is switched
into restricted operation mode. To leave restricted
operation mode, the host CPU must reset CCCR.ASM.
- 0
= No message RAM access failure occurred
- 1
= Message RAM access failure occurred