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Patent Title: Efficient data transfer mechanism for input/out devices having a device driver generating a descriptor queue and monitoring a status queue

Assignee: IBM
Patent Number: US6334162
Issue Date: 12-25-2001
Application Number:
File Date:09-01-2000

Abstract: A method for transferring data between non-contiguous buffers in a memory and an I/O device via a system I/O bus uses a descriptor queue stored in memory. Each descriptor points to a buffer and includes the length of the buffer. The I/O device is provided with the base address of the queue, the length of the queue and a current address which at initialization is the same as the base address. When data is to be transferred a device driver located in the processor sends the number of available descriptors (DescrEnq) to the I/O device which accesses the descriptors individually or in burst mode to gain access to the data buffers identified by the descriptors.


Link to USPTO

IBM Pledge dated 1/11/2005