это на 125стр. злодеи написали:
The module serves the following purposes:
• Copying data from one part of the packet buffer to
another.
• Copying data between the packet buffer and one
of the memory mapped cryptographic engines.
• Calculating a 16-bit checksum over a block of
data, compatible with the checksum used in
standard protocols, such as IP and TCP.
внимательнее присмотритесь к FIGURE 1-1: ENC424J600/624J600 BLOCK DIAGRAM - найдете немало интересного, поверьте мне!
заодно и о dma узнаете