Disc drive reset using power valid, clocks valid and delay crite

Details Disc drive reset using power valid, clocks valid and delay crite Disc drive reset using power valid, clocks valid and delay crite

1995-10-31

1998-04-21

Butler, Dennis M.

395557, 395559, G06F 104, G06F 124

Patent

active

057428000

ABSTRACT:
Method and apparatus for resetting a disc drive during a disc drive reset sequence comprising a sequential three-stage reset using power valid, clocks valid and delay criteria. Input voltage provided to the disc drive is monitored to detect the presence of input voltage at a nominally acceptable voltage level, after which a system clock generator initiates generation of a system clock signal. A lock detector circuit employing a PLL circuit monitors the system clock signal and indicates when the system clock signal has achieved frequency stability by way of an output signal, which enables a counter circuit to initiate a timed delay by counting a predetermined number of the system clock signals. During the timed delay, a disc drive system microprocessor is initialized to a known, desired state and the counter provides a reset signal to the system microprocessor at the completion of the timed delay, indicating completion of the reset sequence. A loss of stability in either the input voltage levels or the system clock prevents the issuance of the reset signal; at such time that the stability of the input voltage levels and the system clock are recovered, the reset sequence is reinitiated.

REFERENCES:
patent: 4679102 (1987-07-01), Wevers et al.
patent: 5019996 (1991-05-01), Lee
patent: 5047876 (1991-09-01), Genheimer et al.
patent: 5107378 (1992-04-01), Cronch
patent: 5262907 (1993-11-01), Duffy et al.
patent: 5454114 (1995-09-01), Yach et al.
patent: 5513358 (1996-04-01), Lundberg et al.
Data Sheet for Motorola MC888916 PLL Clock Driver; pp. 117-124.
Article by T. Kvinge entitled Universal Watchdog Fully Controls .mu.P Reset:, Engineering Design News, May 25, 1995, p. 94.

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