Data integrity assurance in a disk drive upon a power failure

• US 5,359,728 A
• Filed: 04/09/1992
• Issued: 10/25/1994
• Est. Priority Date: 04/09/1992
• Status: Expired due to Term

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Hewlett-Packard Company (HP Inc.)
• Inventors: Piranfar, Ali, Rusnack, Michael R.
• Primary Examiner(s): Beausoliel, Jr., Robert W.
• Assistant Examiner(s): Wright, Norman M.
• Application Number:
  US07/866,377
• Time in Patent Office: 929 Days
• Field of Search: 395/575, 395/425, 371/14, 371/16.1, 371/66, 364/273.4, 364/273.5, 364/264.2
• US Class Current: 714/5.11
• CPC Class Codes: G06F 1/30 Means for acting in the event of power-supply failure or interruption, e.g. power-supply fluctuations for resetting only G06F1/24
• CPC Class Codes: G06F 11/004 Error avoidance G06F11/07 and subgroups take precedence
• CPC Class Codes: G06F 11/0754 by exceeding limits
• CPC Class Codes: G06F 11/1415 at system level
• CPC Class Codes: G06F 3/0601 Interfaces specially adapted for storage systems
• CPC Class Codes: G06F 3/0673 Single storage device

Abstract

A disk drive package includes read/write circuits, a disk drive mechanism and a microprocessor. The microprocessor has a dedicated function input and an interrupt input. The dedicated function input is accessible through an external connector in the disk drive package, but the interrupt input has no direct external access. The microprocessor is programmed to examine the dedicated function input only upon power-up to determine if it has been enabled. The disk drive package is modified to include a circuit that couples the dedicated function input to the interrupt input to the microprocessor. A power supply provides a power fail imminent signal to the dedicated function input, and because the dedicated function input is connected to the interrupt input, such signal causes an interrupt to occur in the operation of the disk drive whereby any write to disk in progress is completed prior to a power fail event.

Claims

1. A disk drive package that includes read/write circuitry and a disk drive mechanism, said disk drive package further comprising:

microprocessor means positioned within said disk drive package and having dedicated disk drive function input and an interrupt input, said dedicated disk drive function input accessible via a first pluggable connector in said disk drive package, said microprocessor means programmed to examine said dedicated disk drive function input only upon power-up to determine if it has been enabled;

circuit means for coupling said dedicated disk drive function input to said interrupt input to enable a power-fail-imminent signal applied to said dedicated disk drive function input to also be applied to said interrupt input; and

power supply means for providing said power-fail-imminent signal, after power-up, to said first pluggable connector, said power fail imminent signal ignored by said dedicated function input, but via said circuit means, causing said microprocessor means to institute an interrupt in operation of said disk drive to enable a write to a disk sector which is in process at a time said power-fail-imminent signal is asserted, to be completed prior to the occurrence of the power failure.

2. The disk drive package as recited in claim 1 further comprising:

a disk drive external interface bus and connector, said bus and connector having no provision for a power fail imminent signal.

3. The disk drive package as recited in claim 2 wherein said disk drive package'"'"'s external interface is an SCSI specified interface.

4. The disk drive package as recited in claim 1 wherein said circuit means includes an inverter that converts said power-fail-imminent signal to a signal recognized by said interrupt input to said microprocessor means.

5. The disk drive package as recited in claim 4 wherein said circuit means includes a pair of pins extend externally from said package, one said pine connected to said dedicated function input and another said pin connected to said inverter, and further including a jumper that electrically connects said two pins so as to make electrical connection therebetween.

6. The disk drive package as recited in claim 1 wherein said interrupt prevents any new writes from commencing until the interrupt is removed.

7. The disk drive package as recited in claim 1 wherein said dedicated function input is a Write Protect function that disables writes to the disk drive package when enabled.