This output indicates whether the request currently being submitted to the user
interface is accepted. If the user interface does not assert this signal after
app_en is asserted, the current request must be retried. The
app_rdy output is not asserted if:
- PHY/Memory initialization is not yet completed.
- All the controller Group FSMs are occupied (can be viewed as the command buffer
being full).
- A read is requested and the read buffer is full.
- A write is requested and no write buffer pointers are available.
- A periodic read is being inserted.