SPRUIU1C July 2020 – February 2024 DRA821U , DRA821U-Q1
Messaging mode requires that all accesses to the queue must go through RINGACC so that all accesses to the memory are controlled and ordered. RINGACC then controls the entire state of the queue, and software has no directly control, such as through doorbells and cannot access the storage memory directly. This is particularly useful when more than one software or hardware entity can be the producer and/or consumer at the same time. Software must access the data through bus accesses to tha RINGACC. As with the earlier example, if there are free queues that need the hardware to both push and pop, then they must be configured as at least messaging mode (or a later mode) and not ring mode.