CN1204413A - Fault-tolerant sample-data servo pattern - Google Patents
Fault-tolerant sample-data servo pattern Download PDFInfo
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- CN1204413A CN1204413A CN 96198931 CN96198931A CN1204413A CN 1204413 A CN1204413 A CN 1204413A CN 96198931 CN96198931 CN 96198931 CN 96198931 A CN96198931 A CN 96198931A CN 1204413 A CN1204413 A CN 1204413A
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Abstract
A headerless, fault-tolerant sample-data servo pattern, comprising an alternating sequence of first and second servo sectors, with the first servo sectors each including a partial track address and circumferential orientation information, and the second servo sectors each including a full track address, provides an absolute indication of a read/write head's circumferential orientation along a given track on a magnetic disk which is robust in the presence of defects in the magnetic recording medium.
Description
Technical field of the present invention
Technical field of the present invention relates to general dismountable boxlike hard disk drive, especially, relates to the system and method for Code And Decode servo-information on a dismountable boxlike hard disk.
Existing technology
Dismountable boxlike hard disk drive is put on market a period of time.As fixed disk drive, dismountable boxlike hard disk drive system is followed low-cost and relative fast access time provides big memory capacity.Yet, not resembling fixed disk drive, dismountable boxlike hard disk drive system makes the user easily substitute the hard disk of a relative higher capacity, allows the convenient exchange of bulk information between remote place and the memory capacity that has increased system widely.
As fixing hard disk drive, dismountable boxlike hard disc drive system uses the W head of a magnetic to go read and write in the data of magnetic disk surface with the field form storage.This panel surface is divided into and is used for the many concentric magnetic orbital of storaging user data record.Read maybe will write data on the dish, this panel surface fast rotational and W head pass through in its surface, the path of the circumference of tracking track or those tracks that data will be stored or read.
For suitable data storage and recovery, each bar track that W head must locator data will be read or write, and accurately follow the tracks of its path along panel surface.Therefore, thus dish drives this read/write operation of method need some to determine track and the accurate radial position of control W head to be carried out on the track of expectation.Prevent that the wrong user of covering from wishing the previous data of having write of preserving, the W head accurate localization is in the write operation particular importance.Realize this, servo positioning information is to be recorded on the disk in advance during fabrication, and is gone moving of control head by the servo-drive system utilization when inter-track is searched for, and will adjust the position of magnetic head at magnetic track when data are write or duplicated.This servo-information is recorded in a plurality of concentric position with uniform interval in advance on each track of disk.The servo sector of a given magnetic track be with their adjacent tracks on radially adjacent company of corresponding sector.
The servo-drive system of many types designed monitoring and correct W head and track centreline between calibration, and provide the locating information to determine tracked particular track to W head.The extention of most of prior art servo patterns is the initial bits of coded of expression magnetic track, or index point.Many such system for content are described in:
B. the anti-spy of Mike " utilizes the track and localization servo-drive system of data head as the absolute fix sensor ", IEEE Tr.Mag Vol.Mag-14, July, 1978; U.S. patent No. No.5,255,131, title " the asynchronous servo identification/address mark that is used for the PRML disk drive system detects "; U.S. patent No. No.4,933,786, title " fault-tolerant indexing model and coding/decoding method "; And U.S. patent No. No.4,459,232, title " phase modulation (PM) servo-drive system ".
The user data record is the space that is recorded between the servo sector.During the formation of these data, for each record initially writes a prefix, provide the positional information of complete track address and annulus to describe the location of relevant record by the data routing controller.This prefix is used for locating thereafter and determines and the record that before read or write relevant record unanimity.In tuning record (toned-recording) system, this prefix also comprises the specified data record and is separated the positional information on every side the servo pulse group.This prefix is only used and is not used by servo-drive system by the data routing controller.
Dismountable boxlike seagate continues development, places additional requirement on servo-drive system.Magnetic track on a drum or a disk and data bit area density continue to increase, for increasing the removable cartridge hard disk that memory capacity has produced potentialization.Realize high memory capacity, the servo sample rate must improve to improve the tracking of high track density, cause compacter, the needs of the better servo-drive system of efficient.However, accurately the read-write head positional information still need radially reach the data that prevent from the circumferencial direction to neglect on the covering preexist dish.
Along with the increase of servo sector density, and the appearance of mech's difference, between the servo sector of different magnetic head read-writes, may there be the crooked of specified circumference; This crooked servo sample interval that under opposite extreme situations, can exceed.When the conversion magnetic head, still need on a new magnetic head, indicate the position of magnetic track immediately, there is no need by the time whole magnetic disk and rotated and just read an index marker.
And, because recording medium defective and imperfection increase the magnetic susceptibility that areal concentration has caused increasing servo error.Therefore needing a kind ofly can provide fixing track location and the circumference directed information no prefix servo sector form to the sampled data servo-drive system.
Another problem occurs in and adopts the rotation activator appliance together with in the dismountable boxlike hard disk drive system with the magnetostriction W head that separates magnetic head and write the gap.In such system, magnetic head can ask radially to relocate in the middle of the operation of reading and writing, and has got rid of the accurate recovery before the writing of prefix zone that routine is used, and therefore can save prefix.The omission of prefix also makes has more space to be fit to the user's data storage.Therefore, be desirable to provide some means, rather than the use of prefix, determine the circumference orientation of W head in any given magnetic track, if particularly system to have a higher potential built-in magnetic head circumferential crooked, and be to use when being called no prefix form.
In addition, it will help providing a compacter servo pattern, and this pattern also provides the absolute indication of a circumference orientation of W head in a magnetic track and do not have to use additional reserved area in the servo sector including this circumference information.It also help provide one in magnetic recording media defective and imperfection in face of the servo pattern that strengthens.The servo pattern that provides one to comprise servo sector also further is provided for it, and these servo sectors recover synchronous when providing the indication of the circumference orientation of W head to allow a data sampling servosystem at head switching operation to surpass in the crooked appearance of magnetic head under the gap length situation of servo sample immediately.Other and more purpose and advantage.
The present invention's summary
The present invention includes the system and method for Code And Decode servo-information on the removable cartridge hard disk in the removable cartridge hard disk drive system.
In one aspect of the invention, disk is in conjunction with comprising the servo sector in three-dimensional multiple zone in a removable cartridge hard disk, these zones can be used to provide a W head in given magnetic track the circumference orientation absolute indication and do not adopt reserved area.This servo pattern comprises that each all has the first order servo sector of circumference orientation, determines the circumference orientation of W head along a given magnetic track.This servo pattern also comprise each all have be described in ± 2
KThe second level servo sector in a coarse localization territory of a track location in the magnetic track.Circumference orientation and coarse localization information are stereoscopic overlap to public domains; The content of public domain is to determine by being used for the sync mark that this servo sector of mark begins.
In another aspect of this invention, the removable cartridge hard disk comprises the servo pattern with circumference alignment regions servo sector in conjunction with one, and these annular regions are radially in abutting connection with the demand of eliminating those specific coding information, for example Gray code along panel surface.Therefore, even under the condition that magnetic track has departed from, W head can read the information of circumference orientation, as adopts a magnetostrictive W head.
The present invention also have on the other hand in, the removable cartridge hard disk drive can be contained in the hardware in conjunction with one or carry out and the response servo sync mark detects and the servo sector counter that progressively increases as software, and their counting is to be confirmed by the circumference alignment regions that reads coding periodically.This removable cartridge hard disk drive can switch the back at magnetic head to be derived the index point information in cycle immediately and not to need to wait for index point from counter.
Brief Description Of Drawings
Various purpose of the present invention, characteristics and advantage will be better understood by the description below in conjunction with most preferred embodiment and accompanying drawing, wherein
Fig. 1 is one and describes the servo pattern figure that prior art comprises the servo sector on the magnetic track that is recorded in disk in the removable cartridge hard disk.
Fig. 2 is a kind of synoptic diagram of prior art removable cartridge hard disk servo sector.
Fig. 3 is improved servo pattern structure according to the present invention, comprises an alternate sequence with servo sector of two kinds of different-formats.
Fig. 4 A is a servo sector figure who adopts in improved servo pattern, according to one or more aspects of the present invention, determines a multiple zone of solid.
Fig. 4 B is a servo sector figure who adopts in improved servo pattern, determines the content in the three-dimensional multiple zone of Fig. 4 A.
Fig. 5 is the block scheme that one or more aspects according to the present invention are used to detect the servo sector detecting instrument of servo-information.
Fig. 6 is a clock signal figure relevant with the servo sector detecting instrument of Fig. 5.
The operation of directional counter in Fig. 7 displayed map 5.
Fig. 8 is the detuner sequence in the displayed map 5 diagrammatically.
Fig. 9 is the block scheme according to index detection in one or more aspects of the present invention and positioning of rotating sensor.
Fig. 9 A schematically demonstrates the form that is applicable to user data on control one magnetic disk surface and produces the method for an index pulse and the directed indication of circumference.
Fig. 9 B is the procedure graph of execution in step among the embodiment of displayed map 9A.
The description of most preferred embodiment
The servo sector 100 of Fig. 1 displayed record on the disk of prior art removable cartridge hard disk.As seen in Figure 1, this servo sector 100 appears at annular space clocklike around each magnetic track 105, with 110 staggered appearance of user data record segment.Though for this magnetic track section of graphic purpose shows it is linear, these magnetic tracks are actually the surface that is arranged on disk with one heart.
Fig. 2 shows a prior art form for the servo sector 200 of removable cartridge disk drive system.Servo sector 200 is write-is taken the lead to-the recovery of reading/automatic gain control (AGC)/retaining zone 210 by one.Servo sector 200 comprises a synchronization zone 220 (distinguishing over the use in " mark " district of back), index area 230, coarse localization district 240 and an accurate positioning area 250.Typically, synchronization zone 220, each all comprises a digit order number sequence index area 230 and coarse localization district 240.Servo sector 200 usefulness user data as shown in Figure 1 alternately separates, and appears at along on the regular annular space that separates of each magnetic track.In single servo section, certain regional format system can write down the multi-user data field, and each is attended by prefix.These methods can be separated data recording around servo sector.
Carry out as an elimination gap of violating the running length of given user data record coding synchronization zone 220, and have one at least based on the transition on the sequential of the next detection of servo-information.Synchronization zone 220 signals are indicated the beginning of a servo sector and are followed by index area 230.Index area 230 generally has a bit, and one of mark is positioned at the index servo sector of the beginning of each magnetic track, or with the distribution pattern of the every sector of a usefulness unity bit coding, covers a spot of sector.Index area 230 follows hard on coarse localization district 240.
The precise location information of any coding simulation form of several technology of accurate positioning area 250 general employing called optical imaging.For example, accurately positioning area 250 can comprise four short pulses arranging with the quadrature form and removes to send a two phase place orthogonal simulation positioning error signal (PES).This arrangement is known as the ABCD pulse mode in the prior art.For the coding precise location information, further you can find among " the servo pulse pattern of the mobile deviation that rugged change and correlation technique cause for magnetic " U.S. Patent number No.08/330368 at title in conjunction with aforesaid technology in detail, signature Richard J Bi Tesen (Richard J.Peterson) is published on October 26th, 1994, and it belongs to donor of the present invention.
Shown in Fig. 3 according to the embodiment of the servo pattern of one or more contents of the present invention.In a removable cartridge disk drive system, type 300 and 300 ' servo sector center on the interval appearance of each magnetic track 405 of disk with regularly spaced annular.Servo sector type 300 and 300 ' with user data segment 410 are staggered appearing on each magnetic track 405.User data segment 410 preferentially adopts existing no prefix technology to be recorded, and can center on servo sector 300 and 300 ' be separated.Although for the section of purpose of description magnetic track 405 shows it is linear, magnetic track is actual to be along the surperficial concentric round setting of disk.
Each magnetic track 405 comprises N servo sector 300 of total and 300.Servo sector 300 and 300 ' is that radial surface along disk is from magnetic track to the magnetic track adjacency.In most preferred embodiment, on the disk in a removable cartridge disk drive system, a servo pattern of each magnetic track 405 comprise N=120 servo sector 300,300 '.
Fig. 4 A and 4B show according to one or more contents of the present invention be used in servo sector 300 and 300 in the improved servo pattern ' form.As existing technology, each servo sector 300 and 300 ' write the multiple district of one to one recovery of reading/automatic gain control (AGC)/retaining zone 310 (the present invention does not have this part), servo synchronous mark district 320, solid 325, a mould positioning area 340 and an accurate positioning area 350 by taking the lead.Shown in Fig. 4 B, between 300 servo sectors and the 300 ' servo sector unique different be the content in three-dimensional multiple district 325.In servo sector 300, the content in three-dimensional multiple district 325 is the directed districts 330 of a circumference, and when relevant with the specific code of servo synchronous mark 320, it carries the circumferential registration indication of a magnetic track servo sector.In servo sector 300 ', the content in three-dimensional multiple district 325 is coarse localization districts 335, and when with servo synchronous mark 320 relevant, it comprises the coarse localization information of determining the magnetic head radial position.When carrying embodiment shows that two zones are that the servo data region that clearly comprises the varying number of dissimilar servo-informations can be overlapping in the multiple district 325 of solid when alternately distributing (that is, the directed and coarse localization district of circumference) in the multiple district 325 of single solid.
In most preferred embodiment, each all comprises a digit order number sequence the directed district 330 in servo synchronous mark district 320, circumference, coarse localization district 335 and mould positioning area 340.
Servo synchronous mark district 320 expression servo sectors 300 or 300 ' beginning.Servo synchronous mark district 320 comprises a class of the servo synchronous mark of two classes, is expressed as sign _ 0 and sign _ 1.The beginning of servo synchronous mark _ 0 expression servo sector 300.The beginning of servo synchronous mark _ 1 expression servo sector 300 '.Even number sector on each magnetic track 405 (that is, sector 0,2,4,6 ... N-2) form servo sector 300 and odd number of sectors (that is, sector 1,3,5,7 on each magnetic track 405 ... N-1) form servo sector 300 '.Therefore, W head can be by the servo synchronous mark that keeps being detected by magnetic head along the orientation of a magnetic track, and the running of sign _ 0 and sign _ 1 is counted and upgraded.
The selection of servo synchronous mark sign _ 0 and sign _ 1 will have the characteristic of violating the running length restriction that is used for the selected channel code of coded data on the disk consumingly.Servo synchronous mark is also selected to be write when appending to-detectability when guaranteeing that media defect occurs during to-the recovery of reading/automatic gain control (AGC)/retaining zone 310, have the automatic rectification error of suitable peak value simultaneously, and have minimum crossing dependency mutually to secondary lobe (peak-to-sidelobe).
In most preferred embodiment, servo synchronous mark sign _ 0 and sign the _ 1st have and can detect the 12-bit character that two random errors occur.In most preferred embodiment, this servo sync mark is:
Sign _ 0=001100000101 (305 sexadecimal)
These selections of sign _ 1=000001101011 (06B sexadecimal) are not only some possibilities, and they also show a maximum seven secondary lobe height of correction automatically, two random errors appearance of permission detection.If N-V 〉=2K+1 can detect the character of N bit when K bit mistake occurring, wherein V is the maximal value of correcting secondary lobe automatically.Here, N=12, K=2 and N-V=5.
Additional special servo synchronous mark can be used to first and second servo sectors of indicating each magnetic track to begin, or other the information of encoding.It is many that such to be chosen under the spirit and scope of the present invention all be possible.
Servo sector 300 comprises the directed district 330 of circumference, determines the annular location of servo sector with the information coding.The directed district 330 of circumference comprises an annular index.First servo sector 300 in magnetic track 405 comprises a circumference orientation values zero.The circumference of reading after in circumference orientation values each servo sector 300 in magnetic track 405 each all increases by 1 in the directed district.So the directed district 330 of circumference provides a directed indication of absolute circumference, it can also be used for compensation, also is used to check the counting of self-monitoring servo sector counting and servo sync mark in addition.
In most preferred embodiment, there are nine (9) bits in the directed district 330 of circumference, comprises that an odd parity bit provides the detecting reliability of enhancing.Because only need six combinations of supporting 120 servo sectors 300 of sum and 300 ', (2 * 2
6＜120), two other bits can be arranged also except parity bit.These two bits are preferentially arranged the binary representation of a head number of coding; It can support quadruplex videotape recorder.
The directed district 330 of circumference is adjacency radially from the magnetic track to the magnetic track on disk.Even the information in the directed district of each circumference as during when head position execution write operation, also can read under the situation of the head skew that may take place with magnetostrictive W head.
Servo sector 300 ' comprises coarse localization district 335.Coarse localization district 335 is ± 2
K-1Determine absolute track location in the magnetic track.Therefore, combine with mould positioning area 340, the coarse localization district 335 in the servo sector 300 ' provides whole track address.
In most preferred embodiment, coarse localization district 335 comprises 9 bits with conventional Gray code pattern-coding.
In most preferred embodiment, K=6 operates corresponding to modulus-64.In this case, coarse localization district 335 determines absolute track location in ± 32 magnetic tracks.Before being recorded on this disk, the content in mould location, coarse localization and circular orientation district is to belong to rll encoder, is designed to the unit distance characteristic that four bits remove to preserve Gray code in such a way at this three bit.This coding has been eliminated the long operation of not expecting that does not have transition on the disk.Alternatively, pulse position (PPM) coding can be used for distributing every two time slots; A transition is recorded in corresponding time slot representative " 1 " or " 0 ".The effect of any coding all is cancelled in servo testing process.
In the removable cartridge disk drive system, servo sector 300 and 300 ' each all combine with the accurate positioning area 350 that rub-out signal to a servo loop in additional position is provided.Accurately positioning area 350 precise location information of can encoding adopts any technology that everybody knows.In carrying embodiment, accurately positioning area 350 adopts four, six or eight short pulses to arrange with quadrature type and removes to transmit leggy orthogonal simulation position error signal to servo loop, as title for described in " being used for distorting and the servo pulse pattern of the mobile deviation that correlation technique causes " U. S. application patent No. No.08/330268 by magnetic.Also have, the operation in servo control processor is in conjunction with accurately location and pattern are located the comprehensive expression that forms a head position.The cycle precision of pattern location is to obtain by the star estimator, and it checks the coarse localization district periodically.
Fig. 5 shows an embodiment who is used to detect the servo sector detector 500 of servo sector 300 and 300 '.
In the embodiment of Fig. 5, readable data signal 502 is provided to the data detection instrument 504 in the servo sector detector 500.This readable data signal 502 is that a peak value detects, digitized signal, and it is from the disk drive recording channel, comprising the W head of scanning disk in the removable cartridge disk drive system.Data detection instrument 504 also receives than the staggered high frequency clock signal of rate of expectation on the line 502.For example, clock frequency can be 50MHz and staggered frequence may be 50MHz/4.The response readings number of it is believed that 502, data detector 504 produce a synchronous serial servo data signal 508 and represent the information that produces again from the digital block of servo sector with the binary digit form.
Serial servo data signal 508 is provided to a special shift register 510, and in carrying embodiment, multiple 12 bit length are held one 12 servo synchronous mark.Shift register 510 produces a parallel data-signal 512, and it is added to two landmark detector 515 and 516.Clock signal 506 also offers the clock signal 507 of sixth that pulsation rate that frequency divider 509 produces a frequency division is the clock signal 506 of the embodiment of the invention.Sub-frequency clock signal 507 is added to one six bit shift register 510A.The output of shift register 510A forms parallel four bits or six bit position data-signals 514.
In first most preferred embodiment, embodiment that should parallel location data signal 514 correspondences is (4) bit width, and servo sector 300 and 300 ' the directed district 330 of circumference, coarse localization district 335 and mould positioning area 340 are to adopt 4/3 sweep length restriction discussed above (RLL) coding.This 4/3 rll encoder is the regular length block encoding; It is designed to minimum effective four bits of shift register 510A are deciphered three bits.
In second most preferred embodiment, the embodiment of these parallel location data signal 514 correspondences is (6) bit widths, and each adopts aforesaid pulse-position modulation (PPM) coding the directed district 330 of circumference, coarse localization district 335 and mould positioning area 340.
Parallel servo data signal 512 offers detection sign _ 0 separately and the voting circuit 515 and 516 of sign _ 1 characteristic.Each majority voting circuit 515 and 516 comprises the biconditional gate of mode cascade (XNOR) comparer 518, its relatively parallel servo data signal 512 and bit pattern corresponding to the servo synchronous mark that will detect.
In most preferred embodiment, landmark detector 515 and 516 is sought a special M-position (M=12 is in once carrying out) pattern in input traffic.The bit of each input occupies the cycle (is six) of N given number clock 506 in once carrying out.Mark Detection shift register 510 comprises N times that M * N distinctive trigger also counted in clock 507 speed.Every group of N trigger is relevant with the single bit in the sign pattern, and every group is detected separately and parallel detection takes place for " all zero conditions " or the generation of " a single state ".These states correspond respectively to " 0 " and " 1 " in the special sign pattern.And keep counting with state array consistent with corresponding tab character position.When this counting at first surpasses sign judgement threshold values, produce a sign and find signal.
In carrying embodiment, majority voting circuit 515 comprises that a generation comprises the first bit pattern generation device 520 of sequence 001100000101 (305 sexadecimal) bit pattern.Majority voting circuit 516 comprises that a generation comprises the second bit pattern generation device 522 of sequence 000001101011 (06B sexadecimal) bit pattern.The first and second bit pattern generation devices 520 and 522 each all may comprise a bit register or latch, perhaps the input for the XNOR comparer of position mode cascade can directly rely on suitable service voltage.
Each XNOR comparer 518 produces a zone bit comparison signal 524 whether the position coupling takes place.Zone bit comparison signal 524 is provided for the adder circuit 526 in each majority voting circuit 515 and 516, and the number summation of its contraposition coupling also produces tag match count signal 528.Therefore this tag match count signal 528 comprises the value of number of bits in the parallel servo data signal that equals to mate with this bit pattern.
This tag match count signal 528 is provided for an amplitude comparator 530 that detection threshold 532 can be provided.Amplitude comparator 530 in each majority voting circuit 515 and 516 relatively tag match count signal 528 and detection threshold 532 is represented detection when its input 528 servo synchronous mark than input 532 greatly the time so that an output signal to be provided.Majority voting circuit 515 provides sign _ 0 detection signal 534 and a majority voting circuit 516 that sign _ 1 detection signal 536 is provided.Therefore unit 515 and 516 forms the digital correlator circuit.
In most preferred embodiment, majority voting circuit 515 and 516 detection threshold 532 equal nine (9), and it also can be other value but will finish various detection threshold.
Sign _ 0 detection signal 534 and sign _ 1 detection signal 536 are added to or (OR) 538 and produce a servo sector detection signal 540.Servo sector detection signal 540 also is added to frequency divider 509 resets it, thereby is to be in the set time relevant with servo synchronous mark 320 by the inspection of clock 507 pulse regularly.Servo sector detection signal 540 and sub-frequency clock signal 507 are added to directional counter 542.The purpose of this directional counter 542 is that counting occurs in the incident of servo section inner driver other parts, and provides one to sign _ 0 with indicate the squelch window that _ 1 characteristic is searched.
The most preferred embodiment of directional counter 542 is presented among Fig. 6.Waveform correlation as shown in FIG. 7.Directional counter 542 comprises the 13-bit servo period binary counter 602 of a receive clock signal 507 and generation servo period count signal 604, as shown in Figure 7.This servo period count signal 604 is added to state decoder 606.Corresponding to clock signal 507, servo period counter 602 increases the counting of servo period count signal 604.
For whole programmability, count A among Fig. 7, B, C, D realize able to programme by structure register (not showing among the figure).The counting of response decoding A, it with continuous servo sector 300 and 300 ' between the expectation clock periodicity corresponding, state decoder 606 produces an accelerating transition edge as shown in Figure 7 in A-count detection signal 608.A-count detection signal 608 is the set inputs that are added to synchronizer trigger 610.At the next cycle of clock signal 507, the Q output terminal of trigger 610 uprises and produce a pulse in servo sector pulse signal 544 as shown in Figure 7.Each pulse in the servo sector pulse signal 544 all be servo sector 300,300 ' time cycle of an expectation of detection indication.Servo sector pulse signal 544 is that the output as directional counter 542 provides, and is used for the data formatting operation of disk.
When detecting the count value of B, state decoder 606 produces a forward level in B-count detection signal 614.B-count detection signal 614 is connected to the first input end with door 616.The Q output of trigger 610 is added to another input end with door 616.Provide B-counter reset signal 618 to arrive or door 612 with door 616.The detection of the B-counting of the end in the servo sector cycle of corresponding expression expectation, B-count resets signal 618 has shown a positive level as shown in Figure 7.The positive level of B-counter reset signal 618 is synchronous reset servo period counter 602 successively.The next clock period behind reset-to-zero, servo period counter 602 begins counting again and reaches A, corresponding to the continuous servo sector 300,300 of expectation ' between the numerical value of clock period, therefore should begin again in the cycle.
B-count detection signal 614 is also connected to the RESET input of synchronous S-R trigger 610.At the next cycle of clock signal 507, the Q output terminal step-down of trigger 610 is to finish the servo detection pulse in the servo sector pulse signal 544.So directional counter 542 produces one for each expectation servo sector 300,330 ' have servo sector pulse signal 544 of a pulse.
At each impulse duration of servo sector pulse signal 544, the counting of state decoder 606 decoding C, corresponding to the numerical value of this clock period just in time be in expectation be used to detect clock periodicity before time of next servo synchronous mark.Corresponding to the counting of decoding C, state decoder 606 produces a forward transition edge on C-count detection signal 624.C-count detection signal is connected to and door 626.With another input end of door 626 be servo sector pulse signal 544.
Produce a sign window asserts signal 628 that is connected to the set input of synchronizer trigger 630 with door 626.This trigger produces a squelch window of drawing together the ideal time of the mark pulse that transmits on the line 540 with bracket.With door 626 in sign window asserts signal 628, produce the corresponding C-count detection of positive level signal 624 servo sector 300,300 ' during begin to uprise.At the next cycle of clock signal 507, the Q output terminal of trigger 630 uprises, and produces a pulse in sign window pulse signal 632.The time cycle that is used to detect servo synchronous mark of the expectation of each pulse indication in the sign window pulse signal 632.
Detect or Mark Detection signal 540 corresponding to servo sector, the directional counter of Fig. 6 be periodically with servo sector 300,300 ' sign _ 0 and the detection of sign _ 1 pulse synchronous.Each servo sector detection signal 540 and sign window pulse signal 632 offer produce servo sector trigger pip 550 with door 634.Servo sector trigger pip 550 is synchronously used numerical value D prestrain servo period counter 602, than C slightly more greatly, and corresponding to the clock period numerical value that is the detection expected time of servo synchronous mark, as the some A that duplicates.The numerical value of this prestrain is to be sent to counter 602 on the online YY.
Servo sector trigger pip 550 is also connected to or door 636, and its output reset flip-flop 630 finishes this pulse in sign window pulse signal 632.Or the E-count detection signal 638 that another input of door 636 is exported by state decoder 606 provides.When servo counter 602 reaches the E value, expectation corresponding to a servo synchronous mark window finishes, state decoder 606 produces a positive level in E-count detection signal 638, it synchronously reset flip-flop 606 with the pulse in the end mark window pulse signal 632, as shown in Figure 7.Perhaps because the defective of magnetic disk surface does not then detect sign at specific servo sector probably, directional counter will slip over this sign of losing so.Therefore, counter also will insert the servo sector of losing.
So leaving cycle that a window duration equals clock signal 506 for the detection of the servo synchronous mark of servo sector 300,300 ' interior, directional counter 542 multiply by the timing window of (E-C).In most preferred embodiment, its clock signal 507 is 50 MHz, C equal 200 and E equal 300, after servo sector begins, the time corresponding cycle be from 4 μ sec. to 6 μ sec., in this case, D equals 80, corresponding to the specified expected time that is used to detect servo synchronous mark of 5 μ sec. after the beginning of servo sector, and the value that offers counter 602 on the online YY should be 250.
In most preferred embodiment, B equals 750, and corresponding to the servo sector cycle of 15 μ sec. duration, and A equals 4250, corresponding to the expectational cycle between the continuous servo sector of 85 μ sec..
Get back to Fig. 5, directional counter 542 provides servo sector trigger pip 550 to provide regularly for the circuit in the servo sector pick-up unit 500 as output signal.Servo sector trigger pip 550 set flip-flops 552 produce a pulse in operation timing sequencer signal 554, as shown in Figure 7.Each all offers demodulation timing sequencer 556 this operation timing sequencer signal 554 and clock signal 507.
Fig. 8 shows the most preferred embodiment of a demodulation timing sequencer 556, and it is a simple base counter status devices.Corresponding to the high level on the operation timing sequencer signal 554, the 810 beginning counting clock cycles of counter in 556 take place in demodulation sequential device.Counter 810 provides a count output signal 812 to state decoder 814.
In most preferred embodiment, when reaching X
1Count value (4 RLL or 6 PPM) time, corresponding to initially rise (representing the end of servo synchronous mark 320) at operation timing sequencer signal 554 and the 3rd of three-dimensional multiple district 325 between the numerical value in 507 cycles of sub-frequency clock signal, state decoder 814 allows to produce in the signal 558 first pulse in locking.Next, reach the count value (8 RLL or 12 PPM) of X2, corresponding to the numerical value of the sub-frequency clock signal 507 between pulse in operation timing sequencer signal 554 and three-dimensional multiple district 325 the 6th, state decoder 814 allows to produce in the signal 558 second pulse in locking.The operation of shift register 584 is being managed in this pulse, it unstring (deserialize) servo sector 300 and 300 ' the content in three-dimensional multiple district 325.
Similarly, numerical value corresponding to the sub-frequency clock signal 507 between separately the 3rd, the 6th and the 9th of pulse in the operation timing sequencer signal 554 and pattern positioning area 340, when reaching Y1, Y2, and Y3 (12 RLL/18 PPM, 16 RLL/24 PPM, with 20 RLL/30 PPM) numerical value the time, state decoder 814 allows to produce the first, the second and the 3rd pulse respectively in the signal 560 in locking.The operation of shift register 576 is being managed in this pulse, it unstring servo sector 300 and 300 ' the content of pattern positioning area.
Return Fig. 5, sign _ 0 detection signal 534 and sign _ 1 detection signal 536 are provided for synchronous S-R trigger 564 and produce a mode select signal 566.Sign _ 0 detection signal 534 is connected to the set input of S-R trigger 564 and no matter when indicate _ 0 be detected its all set mode select signal 566.Similarly, sign _ 1 detection signal 534 be connected to the RESET input of S-R trigger 564 and no matter when indicate _ 1 be detected its all reset mode select signal 566.Signal on the line 566 also is added to processor controls, so it can suitably explain the directed district of circumference on the present bus 586 and the content of pattern positioning area.
Parallel location data signal 514 is provided for modulation code decoder 568.In most preferred embodiment, this demoder 568 is programmable go to decode RLL or PPM encoded data signal.In this case, whether carrying out rll decoder as for definite demoder 568 still is the PPM decoding, can (power-up) carry out corresponding to a numerical value in the internal register that exists in the removable cartridge disc driver when power rises.This with above-mentioned other circuit in the programmatic described be consistent.
The truth table of the demoder 568 among the embodiment of carrying is presented in the table 1.This table can or divide in the class component gate circuit and carry out at PLA.
Table 1
Output RLL input PPM input
000 1001 101010
001 1101 101001
011 0101 100101
010 0111 100110
110 1111 010110
111 1110 010101
101 1010 011001
100 1011 011010
These demoder 568 decodings walk abreast location data signal 514 and produce a parallel decoding location data signal 570.Parallel decoding location data signal 570 is provided for serial Gray code one to one binary translator 572, and these all are the technology that everybody knows.Gray code converter decoding parallel decoding location data signal is to binary mode and produce parallel tracing positional data-signal 574.In most preferred embodiment, demoder 568 three bits of once decoding are three bit width to cause parallel decoding location data signal 570 and parallel tracing positional data-signal 574.Feedback is to obtain from register 576 and 584, makes serial converted from the Gray code to the binary coding.Data structure in shift register 576 and 584 is intrinsic corresponding to Mark Detection in the timing of clock 507.This is to be loaded by resetting of clock 509.
Parallel tracing positional data-signal 574 is provided for first shift register 576.The locking that first shift register 576 also receives from demodulation timing sequencer 556 allows signal 560.
In most preferred embodiment, first shift register 576 is that three bit widths multiply by dibit length and lock the pattern positioning area 340 that comprises six (6) bits.Allow each pulse in the signal 560 corresponding to locking, 576 lockings of first shift register are from three data bit of parallel tracing positional data-signal 574, corresponding to three of servo sector 300,300 ' middle pattern positioning area 340.Pattern positioning signal 578 of first shift register, 576 outputs, it can provide on signal bus, is read by digital signal processor in the removable cartridge disc driver or microprocessor.
Parallel tracing positional data-signal 574 and parallel decoding location data signal 570 also offer a mode selector switch 580.Mode selection switch 580 is gone back receiving mode and is selected signal 566.Select signal 566 corresponding to the mode that is set, it represents the detection of servo synchronous mark sign _ 0, and mode selection switch 580 provides parallel decoding location data signal 570 as output multiplex signal 582.This is corresponding to the detection of servo sector 300 in the directed district 330 of circumference that comprises the servo sector quantity that is not gray encoding as mentioned above.
On the other hand, select signal 566 to be reset corresponding to mode, represent the detection of servo synchronous mark sign _ 1, mode selection switch 580 provides parallel tracing positional data-signal 574 as output multiplex signal 582.This servo sector 300 corresponding to the coarse localization district 335 of the tracking address indication that comprises as previously mentioned gray encoding preferably ' detection.
In most preferred embodiment, second shift register 584 is that three bit widths multiply by three bit long and lock the directed district 330 of coarse localization district 335 and circumference, they each comprise nine (9) bits.In this case, multiplexed coarse localization/circumference phasing signal 586 is eight (8) bit widths.Allow each pulse in the signal 558 corresponding to locking, 584 lockings of second shift register are from three data bit of multiplex signal 582, corresponding to servo sector 300,300 ' in directed district 330 of circumference or coarse localization district 335.
Multiplexed coarse localization/circumference phasing signal 586 of second shift register, 584 outputs, it can provide on signal bus, is read by digital signal processor in the removable cartridge disc driver or microprocessor.When the directed district of circumference had been detected, second shift register 584 also comprised the parity bit signal 588 of a parity bit from circumference directed district 330 outputs.
Multiplexed coarse localization/circumference phasing signal 586 and odd even detection signal 588 all offer the parity detector 590 that detects parity bit in the directed district 330 of circumference.Whether parity detector 590 produces a servoing sector number correct signal 592, indicate multiplexed coarse localization/circumference phasing signal 586 to detect by odd even.Servoing sector number correct signal 592 and mode select signal 566 are added to and door 594.Produce the servoing sector number useful signal 596 of an indication with door 594 from the detection of effective servoing sector number in the directed district 330 of circumference.
Therefore servoing sector number useful signal 596 and multiplexed coarse localization/circumference phasing signal 586 circular orientation that can utilize the index testing circuit in the removable cartridge disc driver to remove the verification W head along particular track 405.Detect RLL/PPM demoder 568 with the additional measurement that is embodied in first-selected executory other validity and whether have code violation, be i.e. any one in 8 inputs combinations in table 1 with not ing.
Fig. 9 shows that one or more aspects according to the present invention are used for a kind of instrument that index detects and positioning of rotating detects in the removable cartridge disk.
In the embodiment of Fig. 9, servo sector pulse signal 902 may comprise the servo sector pulse signal 544 from the directional counter 542 of Fig. 5 and 6 in most preferred embodiment, offer the input end of clock of counter register 904.Corresponding to the pulse in the servo sector pulse signal 902, counter register 904 produces and exports an existing servo sector quantity signal 906.This existing servo sector quantity signal 906 offers that a usefulness 1 adds existing servo sector quantity signal 906 and the increase device 908 that produces next servo sector quantity signal 910.
Next servo sector quantity signal 910 offers " A " input end of selector switch 914.As long as counter register 904 reaches its maximum count value and not by synchronous again, be activated connections " A " input end 912 of the selection A input end 916 of switch 914 arrives the input end 918 of counter register 904.Therefore, next servo sector quantity signal 910 connects the input end 918 of getting back to counter register 904 and is provided as the existing servo sector quantity signal 906 corresponding to the next pulse in the servo sector pulse signal 902.
The embodiment of Fig. 9 also comprises provides the maximal servo sector of maximal servo number of sectors signal 922 register 920.Register 920 can with corresponding to be recorded on the disk servo sector 300,300 that will read by the removable cartridge disk drive ' the maximal servo sector number of quantity load.This maximal servo sector number can be loaded into register 920 from a microprocessor or digital signal processor.All register sum counters are all activated to low (negative edge) edge by the height of the servo sector pulse signal on the line 544.
In most preferred embodiment, corresponding to have 120 servo sectors 300,300 ' the maximal servo sector number of disk be 119.
Maximal servo number of sectors signal 922 and existing servo sector quantity signal 906 offer first comparer 924 separately.Comparer 924 more existing servoing sector numbers and maximal servo sector number and produce a whenever existing servo sector 300 ' all become when being the final servo sector on the particular track 405 overlapping count signal 926 of activation.
Overlapping count signal 926 is by being connected to the selection reset terminal and the XOR gate 930 of selector switch 914 with door 928.Corresponding to the activation of overlapping count signal 926, the input end 918 of selector switch 914 connection count registers 904 is to zero position 932.In addition, the next pulse in servo sector pulse signal 902, counter register 904 reset existing servo sector quantity signal 906 to zero.Therefore counter register 904, incrementer 908 and 924 one of the common formation of first comparer are used to count the overlapping servo sector counter corresponding to the final servo sector on counting servo sector pulse signal 902 and the particular track 405.
Overlapping count signal 926 and servo sector pulse signal 902 also offer gate circuit 934 separately.This gate circuit 934 produce sector signals 936 of the interface controller that offers in the removable cartridge disc driver and index signal 938 be used to refer to each servo sector 300,300 '.Except suppressing for the pulse in the servo sector pulse signal of the beginning servoing sector number 0 of each magnetic track 405, sector signals 936 is servo sector pulse signal 902 then.Index signal 938 shows a pulse corresponding to the servo sector that begins to locate 0 at each magnetic track 405.
When obtaining the initial servo locking with an initial servo sector number initialization servo sector counter.Carry out again still necessary synchronously when during head switching operation, occurring than a servo sector 300,300 ' big annular crooked.This is to utilize circumference phasing signal 940 to finish in the embodiment of Fig. 9, and it comprises multiplexed coarse localization/circumference phasing signal 586 in most preferred embodiment.
Following procedure is then to utilize to detect servoing sector number synchronous servo sector counter again.Synchronizing signal 948 offers trigger 950 again.Synchronizing signal 948 is corresponding to the order from microprocessor in the removable cartridge disc driver or digital signal processor by assert again.When synchronizing signal 948 is assert, be reversed corresponding to the trigger 950 of the next pulse in the servo sector pulse signal 902.
When the directed useful signal 958 of circumference is in when activating, trigger 950 is triggered, and loads servoing sector number signal 962 and just becomes activation.Load servoing sector number signal 962 also offer with 928 reverse input end to forbid that the counting between sync period is overlapping again.Also have, load that servoing sector number signal 962 offers or door 30 with the selection A input 916 that disconnects selector switch therefore just at the input end 918 of the separated counter register 904 from next servo sector quantity signal 910 of sync period.Loading servoing sector number signal 962 also offers the selection B input end of selector switch 914.When loading 962 activation of servoing sector number signal, selector switch 914 joint detection sector number signals 944 are to the input end 918 of counter register 904.
Corresponding to the next pulse in the servo sector pulse signal 902, the detection servoing sector number that the detection sector number signal 944 that counter register 904 usefulness derive from circumference phasing signal 940 provides loads.Simultaneously, the second trigger output terminal 960 is reset, and forbids loading servoing sector number signal 962.Therefore, be under an embargo synchronously again and the servo sector counter begins asynchronous servo sector pulse signal 902.By this process, the servo sector counter is synchronous with the servoing sector number of deriving from the directed information of distinguishing 330 of the circumference that is included in servo sector 300.
Index detection shown in Figure 9 and positioning of rotating testing circuit are also checked the detection miscount in the servo sector counter.Be connected to second comparer 966 separately for counter register 904 input ends 918 and circumference phasing signal 940.This comparer produce an expression servo sector counter whether with the directed district 330 of the circumference that is included in servo sector 300 in the consistent counting precision signal 968 of the directed index of circumference.
In the embodiment of Fig. 9,968 utilizations of counting precision signal are reversed with door 970 and are produced one by directed useful signal 958 gatings of circumference does not compare signal 972.This does not compare signal 972 and is connected to a latch 974, and its is by the next pulse timing in servo sector pulse signal 902 here.Latch 974 one of output are latched counting and are not compared signal 976.Latch counting relatively signal 976 can offer microprocessor or digital signal processor in the removable cartridge disc driver.When second comparer 966 detects a counting and does not match, latch counting relatively signal 976 activate.Therefore microprocessor or digital signal processor may be forbidden all write operations again to disk, and attempt synchronous above-mentioned servo counter again.
Fig. 9 A and 9B show and produce the best approach of indication of circumference orientation that an index pulse and are suitable for controlling the interface control subsystem of magnetic disk surface format of user data.
Line 566,578,586 and 544 comes from the hardware of having described and is added to processor 900.Micro code programs 901 in the processor 900 explain signal 566 (sign class), 578 (pattern location), 586 (circumference orientation/coarse localization) and 544 (servo sectors).It is as coarse localization or circumference orientation that signal 566 is used for guiding explanation bus 586 by program.Must clear and definite microcoding program 901 form the part that the operation control program relevant with servocontrol carried out in bigger being used to, and it is worked in the time slice mode.
This program adopts a constant variables, max_sect (maximum _ sector), and it is defined as, 1 quantity to servo sector; In this is carried out, corresponding to 120 sectors, maximum _ sector=119.An operating variable, svo_sect (servo _ sector) comprises existing servoing sector number.
Start this program, one for the wait of servo sector is formed in the square frame 903, and after this, the sign class at the circumference on the bus 586 on the directed and line 566 is effective.Suppose not have this moment magnetic head to switch, program continues to check the maximum sector value through square frame 905 to 907 at this.If reached maximal value, sector count svo_sect is reset to zero at square frame 909; Otherwise svo_sect progressively increases at square frame 911 and points to next sector.The circumference orientation values that square frame 913 contrasts servo sector on svo_sect provide is carried out and is checked.Recovering the circumference orientation is to increase progressively on a sector; It is in the square frame 915 of coefficient that this calculating is used in 2.If the inspection of square frame 915 failure, its expression or orientation are lost or are detected servo sector and lose.Thereby for the inspection of failure, program branches to 917 is done wrong the recovery and is handled.If check that effectively, control passes through to square frame 919.
Get back to square frame 905 now, carry out the generation of checking that magnetic head switches; Take place if switch, program branches is to square frame 921 and 923.These square frames are waited for the servo sector that comprises the circumference directed information, as representing with sign _ 0 mark.So in square frame 925, the svo_sect variable is forced to the value of the circumference orientation that reads from disk; Moreover, comprise coefficient 2 for above-mentioned reasons.Control passes through to square frame 919 then.Under the situation that magnetic head switches, because interior magnetic head ring defect, the numerical value of conversion circular orientation immediately effectively; This calculating is at square frame 925.
In square frame 919, the value in the svo_sect is written to the external hardware unit and is used for being shown to the interface control subsystem.From square frame 919, program is returned square frame 903 and is gone to wait for next servo sector pulse again.Of the present invention best implement be sign _ 0 time keep for header address information two bits circumference is directed distinguish in.This information is checked at other place by microcoding, and is sequestered in outside the directed district of circumference before it is used by program.
Continue the description of hardware components now, these element bufferings also produce traction pulse 927, and positioning of rotating indication bus 929 is partly adopted by the interface controller/data formatting of disc driver.
The present invention is described with its form of most preferred embodiment.For this disclosed fault-tolerant sampled data servo pattern and detection technique, and other disclosed here correlation technique, for modification that those those of skill in the art did all without prejudice to spirit of the present invention and scope.For example, can replace with the software in the digital signal processor carrying out by top disclosed directional counter and the performed function of demodulation sequence generator, TMS 320C209 or C25 LP digital signal processor series as Texas Instruments obtain same result.And these are revised and all are considered to belong to interest field of the present invention.
Claims (9)
1. the magnetic recording disk in hard disk drive that is suitable for adopting the sampled data servo-drive system, described magnetic recording disk has a servo pattern, it is characterized in that comprising:
One group of first servo sector, each of described first servo sector comprises first logo area with first servo sector Discr., a first three-dimensional multiple district that provides dish to go up the indication of circumference orientation, and first track address district that the indication of associated magnetic track address is provided; And
One group of second servo sector, each of described second servo sector comprises second logo area with a servo sector Discr., the second three-dimensional multiple district that the rough indication of disk address is provided, and second track address district that the indication of associated magnetic track address is provided.
2. magnetic recording disk according to claim 1 is characterized in that described first servo sector and described second servo sector data track on this magnetic recording disk alternately occurs with space interval clocklike.
3. magnetic recording disk according to claim 2, the indication that it is characterized in that being included in the circumference orientation in the described first three-dimensional multiple district are the radial surface ground adjacency along this dish.
4. magnetic recording disk according to claim 1 is characterized in that described first logo area comprises that one first servo synchronous mark is in order to confirm each of the described first servo sector group.
5. magnetic recording disk according to claim 4 is characterized in that the described first servo synchronous mark comprises a digit order number sequence 001100000101 (305 hex).
6. magnetic recording disk according to claim 1 is characterized in that described second logo area comprises that one second servo synchronous mark is used for confirming each of the described second servo sector group.
7. magnetic recording disk according to claim 6 is characterized in that the described second servo synchronous mark comprises a digit order number sequence 000001101011 (06B hex).
8. determine to be used for the method for the sampling servo data system inner periphery orientation of reading and recording in the disk drive of the data of magnetic disk surface for one kind, it is characterized in that comprising following step:
The alternate mode of one first servo sector and second servo sector is write each one group of servo sector that annular is separated that is provided with for one group of data track on the disk of sampling periodically, each first servo sector comprises first a three-dimensional multiple district with circumference directed information, and each second servo sector comprises one second three-dimensional multiple district and the track address district that the indication of associated magnetic track address is provided, and the described second three-dimensional multiple district and track address district provide a complete track address jointly;
Read the data that are stored on the described data track and go to detect in described first servo sector that comprises the described first three-dimensional multiple district one;
Derive a servoing sector number from the described first three-dimensional multiple district; And
Load a servo sector counter with described servoing sector number.
9. be used to detect a device that is recorded in the servo sector on the disk, it is characterized in that comprising:
One has one group of data track and is recorded in its lip-deep disk;
The servo pattern of first servo sector in the servo sector that a kind of N annular that is included as each magnetic track of one group of data track on the disk of sampling periodically and is provided with separated and the alternate mode of second servo sector, each has first logo area that sign _ 0 bit sequence can be provided and first servo sector in the first three-dimensional multiple district of the directed indication of circumference is provided, and each has second logo area that sign _ 1 bit sequence can be provided and provides one group 2
KSecond servo sector in the second three-dimensional multiple district of magnetic track inner track position indication;
One for reading described first and second servo sectors and providing a reading data signal that the W head of contiguous described disk is set;
Data that are used to detect this reading data signal and a serial servo data signal is provided are examined device;
One is connected to the shift register that described data detector is used to receive described serial servo data signal and a parallel servo data signal is provided;
One is connected to the first majority decision circuit of sign _ 0 detection signal that this parallel servo data signal is used to detect sign _ 0 bit sequence and the detection of indication first servo sector is provided;
One is connected to the second majority decision circuit of sign _ 1 detection signal that this parallel servo data signal is used to detect sign _ 1 bit sequence and the detection of indication second servo sector is provided;
The directed register of circumference that is connected to this parallel servo data signal and a circumference phasing signal is provided when sign _ 0 signal is indicated the detection of first servo sector; And
A coarse localization register that is connected to this parallel servo data signal and a coarse localization signal is provided when sign _ 1 signal is indicated the detection of second servo sector.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 96198931 CN1204413A (en) | 1995-11-01 | 1996-10-11 | Fault-tolerant sample-data servo pattern |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US08/548,366 | 1995-11-01 | ||
| CN 96198931 CN1204413A (en) | 1995-11-01 | 1996-10-11 | Fault-tolerant sample-data servo pattern |
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| CN1204413A true CN1204413A (en) | 1999-01-06 |
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| CN 96198931 Pending CN1204413A (en) | 1995-11-01 | 1996-10-11 | Fault-tolerant sample-data servo pattern |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101647062B (en) * | 2007-10-30 | 2012-07-18 | 艾格瑞系统有限公司 | Systems and methods for inter-location control of storage access |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101647062B (en) * | 2007-10-30 | 2012-07-18 | 艾格瑞系统有限公司 | Systems and methods for inter-location control of storage access |
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