SPRUI30H November 2015 – May 2024 DRA745 , DRA746 , DRA750 , DRA756
The buffer descriptor is a central part of the GMAC_SW Ethernet Subsystem and is how the application software describes Ethernet packets to be sent and empty buffers to be filled with incoming packet data.
Host Software sends and receives network frames via the CPPI compliant host interface. The host interface includes module registers and host memory data structures. The host memory data structures are buffer descriptors and data buffers. Buffer descriptors are data structures that contain information about a single data buffer. Buffer descriptors may be linked together to describe frames or queues of frames for transmission of data and free buffer queues available for received data.
The 8K bytes of Ethernet Subsystem CPPI RAM begin at address 0x4848 6000 and end at 0x4848 7FFF from the GMAC_SW perspective. The buffer descriptors programmed to access the CPPI RAM memory should use this address range.