Adapter having data aligner including register being loaded to or from memory with an offset in accordance with predetermined network fragmentation parameters

摘要

A data alignmentation apparatus and method in a LAN adapter. The arrangement includes a data aligner mechanism and a transfer control mechanism that transfer data between this RAM and a PCI bus. A transfer control mechanism pre-calculates the control parameters for the aligner/data-pipe, creates the necessary byte enables for data transfers, and determines the member of transfers needed. This allows the data aligner to create a stream of data words for any arbitrary byte transfer with full PCI data streaming (one 32 bit word every PCI clock cycle). PPThe Data Aligner provides a shifter and data-pipe that is used to convert the RAMs 64 bit words into PCIs 32 bit words. It is bidirectional and is used to convert 64 bit data from the RAM into 32 bit PCI word(s) and vice versa.