Methods and apparatus for saving and restoring scatter/gather list processing context in intelligent controllers

摘要

A circuit and associated methods of operation for a standardized scatter/gather list processor component within DMACs and intelligent IOPs. The standardized circuit architecture and methods provide a register interface and associated processing capabilities to simplify firmware processing to save and restore context information regarding block transfer operations that are paused and resumed prior to completion. Furthermore, the invention provides for architecture and associated methods for processing of standard scatter/gather list elements by a standardized scatter/gather list processor embedded within DMACs and IOPs. Specifically, as applied in the context of SCSI or Fiber Channel IOPs, the scatter/gather list processor of the present invention simplifies IOP firmware processing to save the current block transfer context on occurrence of a SCSI disconnect and to restore the saved context on occurrence of a SCSI reselect.