JPH11146563A - Power supply voltage fluctuation compensator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power supply voltage compensator which enables compensation of the deterioration of the performance of a device to be compensated (for instance a magnetic disc device), even if power supply voltage fluctuates. SOLUTION: A power supply voltage which is supplied at a certain specified voltage value (for instance 5 V±10%) is detected by a power supply voltage fluctuations detecting means (dynamic power supply voltage range detecting means) 1. Meanwhile, optimum parameters corresponding to respective power supply voltages are stores in a memory means 3 before hand. The parameter corresponding to the voltage detected by a power supply voltage fluctuations detecting means is selected to make a compensation object device (signal processing means) 4 operate.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power supply voltage fluctuation compensating apparatus, and more particularly, to a power supply voltage fluctuation compensating apparatus for compensating for deterioration of signal processing performance or the like of a magnetic disk device incorporated in a computer and used for power supply voltage fluctuation. About.

[0002]

2. Description of the Related Art For example, a portable or desktop computer generally uses a magnetic disk as a recording medium, and a magnetic disk drive is required to drive the magnetic disk. When designing the magnetic disk drive, the power supply voltage that can be supplied from the computer main body to the magnetic disk drive is various (for example, a two power supply system of 5 V and 12 V, and a single power supply system of only 5 V). It is necessary to design a plurality of supply voltage specifications so as to cope with the above.

As an example of coping with such a case, Japanese Patent Application Laid-Open No. 7-2
In Japanese Patent Application Laid-Open No. 87916 (hereinafter, referred to as the above-mentioned JP-A-Hei), a power supply voltage supplied to a magnetic disk drive is detected.
There has been proposed a means for setting an optimized operation parameter (for example, an operation parameter of a drive circuit of an actuator) necessary for driving a magnetic disk device in a desired state according to the detected voltage. On the other hand, even if the magnetic disk drive is operating at a fixed power supply voltage specification (for example, nominal 5 V, ± 10%) due to a change in environment when the magnetic disk drive is used, other factors, etc. And the power supply voltage may fluctuate. If this change occurs, even within the above specifications,
For example, a signal processing performance of the filter may be deteriorated due to a reduction in various margins of the signal processing in the filter constituting the magnetic disk device.

[0004]

However, in the case of the power supply voltage fluctuation described above, the means disclosed in the above-mentioned Japanese Patent Application Laid-Open No. HEI 9 cannot cope with the following reasons. In other words, the above-mentioned Japanese Patent Application Laid-Open No. HEI-Hei discloses detecting any one of a plurality of power supply voltages of different specifications (power supply voltages of different specifications, for example, 5 V and 12 V), and selecting an operation parameter suitable for the detected power supply voltage. This does not detect the above-mentioned power supply voltage fluctuation, and the operation of the magnetic disk device may become unstable when the power supply voltage fluctuates. Therefore, an object of the present invention is to provide a power supply voltage fluctuation compensating device capable of compensating for deterioration in performance of a device to be compensated (for example, a magnetic disk device) even when a power supply voltage fluctuation occurs.

[0005]

In order to solve the above-mentioned problems, the invention described in the claims comprises a voltage fluctuation detecting means for detecting a fluctuation of a power supply voltage supplied within an operable range of a compensated device; A parameter storage unit for storing an operation parameter of the compensated device corresponding to the magnitude of the power supply voltage; and an operation parameter corresponding to a detection value of the voltage fluctuation detection unit selected from the parameter storage unit, and the selected operation parameter And control means for operating the compensated device.

With this configuration, even if the power supply voltage fluctuates, the device to be compensated is operated with the operation parameters corresponding to the voltage after the fluctuation, so that the performance of the device to be compensated does not deteriorate.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below based on an embodiment shown in the drawings. (I) First Embodiment FIG. 1 is a block diagram of a magnetic disk drive D according to a first embodiment. This magnetic disk drive D has a nominal voltage of 5 V, ±
It can operate in a power supply voltage range of 10%. The magnetic disk drive D includes a dynamic power supply voltage range detecting unit 1, a control unit 2, a storage unit 3, and a signal processing unit 4 described below. The dynamic power supply voltage range detecting means 1 is connected to the power supply line 11, and the power supply voltage value is divided into an arbitrary number [for example, a range between 4.5V to 5.5V is divided into seven, FIG.
Reference], the power supply voltage level signal corresponding to the detected value is always detected to which range the voltage belongs to (for example, belongs to “range 5 (4.9 V to 5.1 V)”). 12 is generated.

The control means 2 controls the power supply voltage level signal 1
2 according to the current power supply voltage range [for example, “range 5
(4.9 V to 5.1 V) "], and transmits a data request signal 21 requesting an optimal parameter (described in detail below). The storage means 3 stores optimum parameters in each power supply voltage range, and transmits an optimum parameter data signal 31 corresponding to the data request signal 21 to the control means 2.

The signal processing means 4 includes, for example, an automatic variable gain amplifier (AGC), a modulation / demodulation circuit, a filter,
There are an R / W channel having a function such as an equalizer, and an R / WLSI having a preamplifier and a write driver for amplifying an output signal from a head. In the signal processing unit 4, the parameter writing signal 22 from the control unit 2 is output.
Rewrites the operation parameter. The R
The / W channel parameters include, for example, filter cutoff frequency characteristics, boost (gain adjustment of the entire frequency characteristics), write (write) timing adjustment, group delay (group delay), and the like. Also, R / WLS
The parameters of I include, for example, a write current and a sense current for adjusting the sensitivity of a preamplifier corresponding to the MR head. As for the parameters to be set, optimum values may be obtained through experiments and the like.

Next, the operation of this embodiment will be described by dividing it into (1) a schematic operation and (2) a detailed operation. (1) Schematic operation The control unit 2 that has received the power supply voltage level signal 12 from the dynamic power supply voltage range detection unit 1 determines that the power supply voltage range indicated by the power supply voltage level signal 12 (for example, “Range 5”) If it is different from the range up to (for example, “range 2”),
The storage means 3 stores a data request signal 21 requesting an optimum parameter for the current power supply voltage range (in this case, “range 5”).
Send to The storage unit 3 transmits a parameter data signal 31 corresponding to the data request signal 21 to the control unit 2. Subsequently, the control means 2 transmits a parameter writing signal 22 to the signal processing means 4 so that the parameters correspond to the contents of the transmitted parameter data signal 31, and rewrites the parameters of the signal processing means 4. The signal processing means 4 is operated by the rewritten operation parameters.

(2) Detailed Operation As means for coping with power supply voltage fluctuations out of specifications, such as abnormal lowering of the power supply voltage, there is a means for applying, for example, write protection (write protection). The present embodiment and the second embodiment to be described next are not for the case of such abnormal decrease and the like, but for the power supply voltage fluctuation (5 V ± 10) within the specification of the device.
%), In which the vicinity of the power supply voltage is finely set so as to be an optimum parameter for the fluctuation.
For example, when the power supply voltage decreases more greatly affects performance degradation than when the power supply voltage increases, FIG.
As shown in (A), the range of the low voltage portion is set more finely. That is, the range from 4.5V to 5.1V is 0.1V.
The range is set in units, and the range of 5.1 V to 5.5 V is set in 0.2 V units. When there are a plurality of power supply voltages (for example, 5 V and 12 V),
The range is set for each type of power supply voltage in the same manner as in the present embodiment.

In this case, it is preferable to use the optimum parameters independently if the change of the parameter to be set for each power supply voltage variation is independent, and if not, the optimum parameters for the two sets are used. For example, in the above-mentioned R / W channel parameters, the write (write) timing adjustment is independent, but the optimal combination of the cutoff frequency and the group delay and the combination of the boost and the group delay are respectively optimum. There are combinations. This optimum combination is used as a parameter. The storage means 3 for storing the optimum parameters is preferably of a rewritable type. The reason is that when the apparatus has a function of automatically adjusting and determining the current optimum parameter, the data can be rewritten and the latest optimum parameter is always stored. Specifically, a random access memory (RAM), a nonvolatile flash memory, or the like is preferable. In the absence of these functions, a read-only memory (ROM) that can be rewritten under predetermined conditions
May be.

According to this embodiment, when the power supply voltage fluctuates, the data reproduction error can be reduced by setting the parameter of the signal processing means 4 to a value most suitable for the power supply voltage. Also, dynamic power supply voltage range detecting means 1
By finely setting the power supply voltage detection range of FIG.
(A)), fine control is also possible.

(II) Second Embodiment FIG. 2 is a block diagram of the present embodiment. The same reference numerals are given to the parts already described, and duplicate description is omitted. In FIG. 2, the elapsed time detection unit 5 is configured to change the current power supply voltage (for example, the voltage of “range 5”) indicated by the power supply voltage level signal 12 from the dynamic power supply voltage range detection unit 1 to another voltage range (for example, , “Range 2”), the elapsed time after the shift to the voltage range (in this case, “Range 5”) is detected, and a predetermined elapsed time set value 52 (see the lower right of FIG. 4) is detected. If it is within the same power supply voltage range for more than the time, a time lapse detection signal 51 is transmitted to the control means 2. In this way, if the power supply voltage has an instantaneous fluctuation, it can be ignored and stable operation can be achieved. The host 6 sends a parameter change permission signal 61 to the control unit 2 for determining whether there is a problem in the operation of the apparatus even if the parameters of the signal processing unit 4 are rewritten. The reference clock generating means 7 transmits a reference clock signal 71 for synchronizing the operations of the control means 2, the elapsed time detecting means 5 and the host 6.

Next, the operation of this embodiment will be described by dividing it into a schematic operation and a detailed operation. (1) Schematic operation The schematic operation will be described based on the flowchart shown in FIG. In FIG. 3, the control means 2 recognizes a change in the power supply voltage range in which the parameter is currently set based on the power supply voltage level signal 12 (step S1). The elapsed time detecting means 5 is an arbitrary set time (elapsed time set value 52) in which the power supply voltage range changes based on the power supply voltage level signal 12.
It is determined whether or not the state is maintained (step S2). If the state is maintained at the elapsed time set value 52 or more, the time elapse detection signal 51 is sent to the control means 2. Upon receiving the time lapse detection signal 51, the control means 2 determines whether the parameter permission signal 61 from the host 6 indicates a parameter change permission state at that time (step S).
3) If it is in a changeable state (step S3: YE)
S), the optimum parameters for the power supply voltage range at that time are retrieved from the storage means 3, and the parameters are set in the signal processing means 4 (step S4).

(2) Detailed Operation In FIG. 2, the elapsed time detecting means 5 monitors a change in the power supply voltage range for an arbitrary time, so that it is convenient if it has a function of changing the set time. Reference clock signal 7
1 is preferably a square wave having a constant period as shown in FIG. The time lapse detection signal 51 indicates “HIG” as shown in (d) of FIG. 4B when detecting a lapse of time equal to or longer than a set time after the movement of the voltage range.
H ”, and if the parameter is changed there,“ LO ”
W ", if the parameter change permission signal 61 does not indicate the parameter change permission state, and it is still detected that the set time has passed since the movement of the voltage range at the next timing, the signal is changed to" HIGH ". It is preferable that the signal be maintained, but when the voltage range returns to the original state even before the parameter change, the signal becomes “LOW.” The parameter change permission signal 61 is, for example, as shown in FIG. "LOW" if possible, "HIG" if impossible
A signal that always indicates the state, such as H ″, is preferable in terms of timing control.

FIG. 4 shows a specific example. FIG. 4 (A)
When the power supply voltage range is determined as described above (range "1" to "7"), the power supply voltage fluctuates as shown in FIG. Let's say that The power supply voltage range of the power supply voltage (a) at the rising edge of the reference clock is:
It is the range number (5-1) shown in (b). FIG. 4 shows an example of a change of the parameter change permission signal 61 when the elapsed time set value 52 set in the elapsed time detection means 5 is two cycles (two clocks) of the reference clock signal.
If (e) of (B) is assumed, the time lapse detection signal 5
The state of change of 1 is as shown in (d) of FIG. Here, the time lapse detection signal 51 indicates “HIGH” in a detection state, and “LOW” indicates a non-detection state. In the parameter change permission signal 61, the parameter change permission state is "LOW", and the parameter change permission state is "HIGH".
And

At the timing (i) in FIG. 4B, the elapsed time detection signal 51 (d) is "HIGH", but the parameter change is permitted because the parameter change permission signal 61 (e) is "HIGH". Absent. At the timing (ii), since the time lapse detection signal 51 is “HIGH” and the parameter change permission signal 61 is “LOW”, the operation of changing parameters is performed. According to the present embodiment, in addition to the effects of the first embodiment, by adding the elapsed time detecting means 5, it is possible to perform control such that the power supply voltage is not excessively sensitive to an instantaneous change or the like. Also, the addition of the function of receiving a parameter change permission signal from the host 6 causes the parameters to be changed carelessly, resulting in data reproduction errors,
In addition, there is an effect that the operation can be prevented from becoming unstable.

In the above embodiment, the case of parameters of the signal processing means has been described. However, the present invention is not limited to the signal processing means, but may be applied to any circuit having a parameter setting function on a device such as a servo circuit or a controller of the entire device. Of course, the present invention can be applied to this.

[0020]

As described above, according to the present invention, the fluctuation of the power supply voltage is always detected, and the operation parameter adapted to the detected power supply voltage is selected to operate the compensated device (for example, a magnetic disk device). Since the operation is performed, it is possible to compensate for the deterioration of the performance of the device to be compensated even when the power supply voltage fluctuates.

[Brief description of the drawings]

FIG. 1 is a block diagram of a first embodiment of the present invention.

FIG. 2 is a block diagram of the second embodiment.

FIG. 3 is a flowchart showing a compensation operation when a power supply voltage fluctuates in the second embodiment.

FIG. 4 is a diagram showing a specific operation in the first and second embodiments.

[Description of sign]

 REFERENCE SIGNS LIST 1 dynamic power supply voltage range detection means (voltage fluctuation detection means) 2 control means 3 storage means (parameter storage means) 4 signal processing means (compensated device) 5 elapsed time detection means 6 host 7 reference clock generation means 11 power supply line 12 Power supply voltage level signal 51 Time elapsed detection signal 61 Parameter change permission signal 71 Reference clock signal

Claims (8)

[Claims] 1. A voltage fluctuation detecting means for detecting a fluctuation of a power supply voltage supplied within an operable range of a compensated device, and a parameter for storing an operation parameter of the compensated device corresponding to a magnitude of the power supply voltage. Storage means; and control means for selecting an operation parameter corresponding to a detection value of the voltage fluctuation detection means from the parameter storage means, and operating the compensated device based on the selected operation parameter. Power supply voltage fluctuation compensator. 2. The apparatus according to claim 1, wherein said parameter storage means divides a voltage within a range in which said compensated device is operated into a plurality of voltage sections, and stores operation parameters for each of said divided voltage sections. 2. The power supply voltage fluctuation compensator according to 1. 3. The power supply voltage fluctuation compensating apparatus according to claim 1, wherein the division of the voltage area is performed by finely dividing a voltage region that greatly affects performance degradation of the compensated device. 4. The power supply voltage fluctuation compensator according to claim 1, wherein said parameter storage means includes means capable of changing a stored operation parameter. 5. The power supply voltage fluctuation according to claim 1, further comprising an elapsed time detecting means for detecting an elapsed time after shifting from one divided voltage area to another voltage area. Compensator. 6. The power supply voltage fluctuation compensating device according to claim 1, further comprising a changeability determining unit for determining whether the operation parameter stored in said parameter storage unit is changeable. 7. The power supply voltage fluctuation compensating device according to claim 1, wherein said change availability determining means is a host computer connected to the device to be compensated. 8. The power supply voltage fluctuation compensating device according to claim 1, wherein said compensated device is signal processing means constituting a magnetic disk device of a portable computer or a desktop computer. .