driver supports the Sonic Inc. Silicon Backplane, the interblock
communications architecture that can be found in most Broadcom
A bus connects all of the Silicon Backplanes functional blocks.
These functional blocks, known as cores, use the Open Core Protocol
(OCP) interface to communicate with agents attached to the Silicon
Each NIC uses a chip from the same chip family.
Each member of the family contains a different set of cores, but
shares basic architectural features such as address space definition,
interrupt and error architecture, and backplane register definitions.
Each core can have an initiator agent that passes read and write
requests onto the system backplane and a target agent that returns
responses to those requests.
Not all cores contain both an initiator and a target agent.
Initiator agents are present in cores that contain
host interfaces (PCI, PCMCIA), embedded processors (MIPS),
or DMA processors associated with communications cores.
All cores other than PCMCIA have a target agent.