Browse Prior Art Database

Second Command Handling for AT Interface

IP.com Disclosure Number: IPCOM000104576D
Original Publication Date: 1993-May-01
Included in the Prior Art Database: 2005-Mar-19
Document File: 2 page(s) / 46K

Publishing Venue

IBM

Related People

Iwasa, H: AUTHOR [+3]

Abstract

Disclosed is a procedure for second or overlapped command handling for a hard disk drive (HDD) connected to the AT interface. This procedure allows a host data transfer to be started by a hardware for a first sector and to be continued with only one intervention of a microprocessor. This improves the performance of data transfer and executes a second command correctly.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 59% of the total text.

Second Command Handling for AT Interface

      Disclosed is a procedure for second or overlapped command
handling for a hard disk drive (HDD) connected to the AT interface.
This procedure allows a host data transfer to be started by a
hardware for a first sector and to be continued with only one
intervention of a microprocessor.  This improves the performance of
data transfer and executes a second command correctly.

      A distinctive feature of this procedure is to start a host data
transfer by a hardware or hard disk controller (HDC) for a first
sector.  To this end, the HDC includes a command decoder for decoding
a command from a host to thereby start a host data transfer for a
first sector.  Data of remaining sectors are transferred with only
one intervention of a microprocessor.  After the intervention, the
HDC continues the data transfer without aid of the microprocessor.

      The following procedure enables to execute a second command
correctly and effectively.

1.  Set parameters.
    A host system sets parameters to execute a command.
2.  Set a command.
    The host system sends a command to the HDC.
3.  Start data transer by a hardware.
    The HDC decodes a host command and starts data transfer for a
    first sector.
4.  Read parameters by a microprocessor.
    HDD control program reads the parameters set by the host system
    to execute the command.
5.  Complete data transfer by the hardware.
    The HDC completes t...