I have no idea about this interface, If I want a cortex-M processor work with a cortex-A or R processor in a small system, will this port provide a fast path between these two processors?
Thank you Ronan, but I don't find any IPs that can be connected to this port in ARM IP products, does that means I need to design my own IP to extend the processor?
Yes, correct.
Co-processor designs used to be more common to accelerate specific operations. System design advancements make these less valuable nowadays. They are often implemented simply as memory mapped peripherals.