SPRUJ17I March 2022 – August 2025 AM2631 , AM2631-Q1 , AM2632 , AM2632-Q1 , AM2634 , AM2634-Q1
The processor which wishes to send a message to another processor writes the message to the mailbox memory space, then interrupts the receiver processor. The receiver processor acknowledges the interrupt, then reads the message from the mailbox memory space. The receiver informs the sender that the message is read by an interrupt, which is acknowledged back by the sender. The sender must not initiate another message to the same receiver until the previously initiated mailbox interaction with the same receiver is complete.
The following sequence is followed for performing a mailbox communication.
The mailbox scheme ensures the number of mailbox interrupts to a processor is always only 2, regardless of the number of processors in the SoC. (MBOX_READ_REQ and MBOX_READ_DONE)
Every processor is always writing to its own designated mailbox registers.