Browse Prior Art Database

Automated Multiple Command Queuing

IP.com Disclosure Number: IPCOM000123424D
Original Publication Date: 1998-Nov-01
Included in the Prior Art Database: 2005-Apr-04
Document File: 2 page(s) / 44K

Publishing Venue

IBM

Related People

Ishibashi, K: AUTHOR [+3]

Abstract

Disclosed is a method for queuing multiple SCSI commands without the microprocessor intervention. Our method first searches a vacant space of the memory automatically after receiving a command, stores the command to the searched space, and stamps the address as an index. Our method not only decreases the amount of microprocessor intervention, but also reduces the overall SCSI command overhead.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 65% of the total text.

Automated Multiple Command Queuing

   Disclosed is a method for queuing multiple SCSI commands
without the microprocessor intervention.  Our method first searches a
vacant space of the memory automatically after receiving a command,
stores the command to the searched space, and stamps the address as
an index.  Our method not only decreases the amount of microprocessor
intervention, but also reduces the overall SCSI command overhead.

   This method is composed of 3 parts.
  Figure 1 shows Queuing Area to store a received command.
  Figure 2 shows Valid Flag to validate the queued command.
  Figure 3 shows Index to indicate the order of queuing.

These figures also show an example of queuing.
          4 |           |
            +-----------+   |0|0|0|0|0|0|0|0|0|0|0|0|0|0|0|0| 2
          3 |           |   +-------------------------------+
            +-----------+   |0|0|0|0|0|0|0|0|0|0|0|0|0|0|0|0| 1
          2 |           |   +-------------------------------+
            +-----------+   |0|0|0|0|0|0|0|0|0|0|0|1|1|1|0|1| 0
          1 |           |   +-------------------------------+
            +-----------+    F E D C B A 9 8 7 6 5 4 3 2 1 0
          0 |           |
            +-----------+
      index
               Figure 1                Figure 2
        ...