Command queueing engine

Details Command queueing engine Command queueing engine

2007-02-20

2007-02-20

Park, Ilwoo (Department: 2182)

Electrical computers and digital data processing systems: input/

Input/output data processing

Input/output command process

C710S006000, C710S039000

Reexamination Certificate

active

09183694

ABSTRACT:
The present invention includes a Command Queuing Engine (CQE) that is a firmware-assist block which processes some of the firmware tasks related to command and context management preferably for SCSI. When enabled, CQE will decode SCSI commands as they arrive, and determine if DMA contexts can be automatically configured and started to transfer the data for those commands. CQE can also program DMA contexts to automatically return status information either after the disk has completed a transfer (as in non-cached writes) or after the DMA transfer is completed (as in reads or cached writes). CQE also utilizes a buffer-based linked-list to queue the SCSI commands as they arrive for future DMA context configuration. The present invention provides automated recognition and linking of commands belonging to a common thread, i.e., are sequential. The present invention also provides extensive thread boundary information and flexible firmware control for reordering commands. Automatic TE entry generation and storage to buffer memory, and automatic TE retrieval from the buffer memory and execution of entire command threads are further features provided by the present invention. As a result, bus command response latency is decreased by reducing the delay for the command to be started and at the end of the data transfer for status to be send. Disk efficiency is increased by reducing the latency to back-fill or empty a buffer memory segment of data that will be transferred. Furthermore, the present invention is a low-cost trade-off between hardware and firmware functionality.

REFERENCES:
patent: 3350694 (1967-10-01), Kusnick et al.
patent: 4262332 (1981-04-01), Bass et al.
patent: 4543626 (1985-09-01), Bean et al.
patent: 4615001 (1986-09-01), Hudgins, Jr.
patent: 4783730 (1988-11-01), Fischer
patent: 4805137 (1989-02-01), Grant et al.
patent: 4843544 (1989-06-01), DuLac et al.
patent: 4905184 (1990-02-01), Giridhar et al.
patent: 5003465 (1991-03-01), Chisholm et al.
patent: 5146578 (1992-09-01), Zangenehpour
patent: 5208745 (1993-05-01), Quentin et al.
patent: 5233692 (1993-08-01), Gajjar et al.
patent: 5276684 (1994-01-01), Pearson
patent: 5315708 (1994-05-01), Eidler et al.
patent: 5339449 (1994-08-01), Karger et al.
patent: 5347638 (1994-09-01), Desai et al.
patent: 5371861 (1994-12-01), Keener et al.
patent: 5379381 (1995-01-01), Lamb
patent: 5404549 (1995-04-01), Tausheck
patent: 5434976 (1995-07-01), Tan et al.
patent: 5471639 (1995-11-01), Harrington
patent: 5483641 (1996-01-01), Jones et al.
patent: 5504868 (1996-04-01), Krakirian
patent: 5522054 (1996-05-01), Gunlock et al.
patent: 5524268 (1996-06-01), Geldman et al.
patent: 5586295 (1996-12-01), Tran
patent: 5625778 (1997-04-01), Childers et al.
patent: 5647057 (1997-07-01), Roden et al.
patent: 5696930 (1997-12-01), Garetz et al.
patent: 5721954 (1998-02-01), Shrock et al.
patent: 5732223 (1998-03-01), Moore et al.
patent: 5740466 (1998-04-01), Geldman et al.
patent: 5745731 (1998-04-01), Kim et al.
patent: 5781799 (1998-07-01), Leger et al.
patent: 5781803 (1998-07-01), Krakirian
patent: 5784649 (1998-07-01), Begur et al.
patent: 5794069 (1998-08-01), Chisholm et al.
patent: 5828901 (1998-10-01), O'Toole et al.
patent: 5870583 (1999-02-01), Maeda
patent: 5923896 (1999-07-01), Young
patent: 6029226 (2000-02-01), Ellis et al.
patent: 6049842 (2000-04-01), Garrett et al.
patent: 6081849 (2000-06-01), Born et al.
patent: 6108722 (2000-08-01), Troeller et al.
patent: 6141731 (2000-10-01), Beardsley et al.
patent: 6154793 (2000-11-01), MacKenna et al.
patent: 6199121 (2001-03-01), Olson et al.
“High Performance DMA Controller/CPU Interface Mechanism”, IBM Technical Disclosure Bulletin, vol. 36, No. 2, Feb. 1993, pp. 131-133.

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