JPS60201730A - Binary data processing system - Google Patents

Abstract

PURPOSE:To attain the conversion with an excellent code conversion parameter with reference to a prescribed conversion table when a 4-bit signal is code- converted into a 5-bit signal. CONSTITUTION:A pattern of the data obtained every 4 bits of a binary data train is converted into a 5-bit code with reference to a T1 conversion table as shown. Then data trains P1-P5 are selected to satisfy the T1 conversion table when the 4-bit data is expressed in D1-D4 together with the 5-bit data expressed in P1-P5 respectively. Then the 4-bit data is converted into the 5-bit data. The code conversion performed with the conversion table can be attained with a simple logical circuit and is suited to the conversion into an LSI. This ensures the conversion with an excellent conversion parameter.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a system for converting binary data into binary data suitable for data processing when recording binary data on a recording medium and reproducing it from a recording medium in electronic devices such as magnetic disks and optical disks. The present invention relates to a method for encoding and decoding binary data that is converted into a base code sequence, and/or an electronic device having the encoding method.

Traditionally, it has been necessary to record large amounts of information in electronic devices such as magnetic disks and optical disks.
When recording decimal data.

It was essential to improve recording density.

FIG. 1 is an explanatory diagram of an example of a conventional encoding method, and FIG. 1(a) shows an example of a bit pattern of an original binary data series, with logic , rlJ, and To indicates the bit interval. Figures (b) and (d)
is an example of a conventional encoding method, and (b) in the same figure is an example of a conventional encoding method.
It is called the Modified MF method, and is shown in the same figure (
d) is the 5PM method (3PositionModula
The MFM method is an example of a model to which each method is applied.
30, 5540, 5350, etc.), and 3P
The M method uses Univac's magnetic disk system [(8434
) is used. The algorithm of each method is MFM
In the method, the original data "Month.

Corresponding to "0", convert to "olj, [Xoj. However, rXJ Fi, in the encoded sequence after conversion,
It becomes multiple logics (1→0.0→1) of the sign bit immediately before. As shown in Table 1, the SPM algorithm separates the original data into 3-bit units and converts them into 6-bit codes.

Table 1 3PM encoding algorithm &.

Note that the code sequence converted by each encoding method is "1"
A recording current is created so that the signal causes magnetization reversal at the bit "0" and does not cause magnetization reversal at the "0" bit, and is recorded on the recording medium. Figure 1(a), (
e) is the waveform (NRZ signal) of the recording current of the code sequence encoded by the MFM method (in the figure) and the 3PM method (d) in the figure.

Generally speaking, it is difficult to record on magnetic media.

(a) When the magnetization reversal interval (recording wavelength) becomes shorter, the magnetic transitions caused by the previous and subsequent magnetization reversals interfere with each other, causing errors when decoding the reproduced signal.

(b) Demodulation phase margin during reproduction with respect to recording wavelength (TV
) (described later) is also small, the error described above is likely to occur (c) If the recording wavelength is large compared to the period of the demodulation clock signal created from the reproduced signal, the clock described above may not be reproduced accurately. It becomes impossible to create a signal, and the same error as mentioned above is likely to occur.

(b) When the ratio between the maximum value and the minimum value of the magnetization reversal interval increases, waveform interference (referred to as pattern peak shift) of the reproduced signal becomes large, and the above error is likely to occur.

For this reason, in general encoding methods, the above
The following variables are given as parameters indicating the ability including the four items (b), (-now, ni).

Now, in a certain encoding method, an m-bit binary data sequence is converted into an n (n1m)-bit binary code sequence, and a code "1" is arbitrarily selected from the converted code sequence.
and the code "0" between the next code "1", so let the minimum fi & be d and the maximum value be k.

Twin (minimum magnetization reversal interval)=-(d+1)To(
1) 'rmax (maximum magnetization reversal interval) = , (]c
+i)To(2)'LK (Demodulation clock period)
” ' To (5) T, (Demodulation phase margin) = -HT
o(4) However, it is given in the T01 original data period. Hence, the above explanation! D. (1)
It is desirable that the values of equations and (4) are larger (from the above explanations (a) and (b)), and the values of the demodulation four-cycle period (3) and the maximum magnetization reversal interval shown below. Ratio ((5)
formula) and the ratio of the maximum and minimum magnetization reversal intervals (formula (6))
It is desirable that it be very small.

The above parameters are shown in Table 2 for the MFM and SPM encoding methods.

Furthermore, as mentioned above, in the general encoding method, the original data is converted every m bits into an n-bit code, and the 00 run length of the converted code is limited to d or more and k or less (m+n
yd+k) The number of data bits handled, m (m≦n), affects the hardware of the device. It is generally desirable that m is smaller. Furthermore, conventionally, many systems have used ROM or the like as hardware for encoding and decoding, but a system configured with a random logic array is preferable from the viewpoint of LEII implementation. 1fC Generally, a so-called DC-free code is also desired in which fluctuations in the DC component of the encoded signal are suppressed. D07 Ri-1 sign is cumulative charge fluctuation (DSViDigita 1 day un Va
ration) is a finite code. code sequence to NR
Let Wjl be the first digit of the jth recording pattern in the recording pattern series modified by Z engineering, then the charge of this recording pattern itself, Qj, is expressed as QjK2ΣW,B-n-1. . This corresponds to giving a charge of +1 when the digit Wj1 is 1 and a charge of -1 when the digit Wj1 is a mouth. And the cumulative charge up to the #1 recording pattern is defined by , which is based on the fact that Dlff is finite.

It's called 7 Lee.

From what has been explained above, the present invention has large Tm1n and Tw, small TmaVCIKTmax/'rmin of 1, encoding and national code hardware that can be realized with an extremely simple logic circuit, and furthermore, DC7! An object of the present invention is to provide an electronic device having a data processing method such as a J-encoding method, its decoding method, and/or the encoding and decoding method.

Hereinafter, five aspects of the present invention will be described in detail with reference to the drawings.

FIG. 2 is a block diagram of the configuration of an electronic device that performs a digital modulation method for magnetic disks, optical disks, etc. to which the present invention can be applied. 1 is an information source or its input part; 2 is an information source encoder for suppressing redundancy of information in the information source 1; Bandwidth compression compresses the transmission frequency band in an analog way, and high-efficiency coding is a digital method that attempts to reduce the average bit rate per pixel (sample value), and its semantic value is Shima et al. are close to amplitude compression. Reference numeral 3 denotes a communication path and transmission path channel encoding unit, which includes error correction, digital modulation, and the like. Reference numeral 4 denotes a recording/reproducing system for the magnetic disk, optical disk, etc. described above. Further, 5, 6 IIi is a decoding unit for decoding the encoded data in the encoding units 2 and 3 described above. , 7 is an output unit that outputs the information obtained through the above processing.

Figure M5 is a block diagram showing an example of the recording/reproducing system 4, which is an example applied to a video disc.

First, let's talk about the signal recording system. A multi-light source 9, for example, a semiconductor laser, emits blinking light in response to a drive signal from a signal source 8 based on input data. Note that the signal source 8 will be discussed including the encoding section 2.3 in FIG. The light beam emitted by the light source 9 is converted into a parallel light beam by a collimator lens 10, a grating 11, a polarizing plate 12. The light passes through an optical element 13 whose transmission/reflectance has polarization dependence. A dot is formed on the perpendicular magnetic recording medium 15 by the objective lens 14. Although the semiconductor laser light is approximately P-polarized with respect to the optical element 13, the polarizing plate 12 is also installed with the polarization direction in the P direction.

The grating 11 separates the beam angle in order to focus a sub-spot for tracking detection onto the perpendicular magnetic recording medium 15 using the objective lens 14.

At this time, six point images are formed on the recording medium 15 due to the action of the grating 11. Of these three point images, two point images used for tracking signal detection during reproduction are the ±1st-order diffracted light of the grating 11, and the remaining one is the undiffracted light (zero-order light). By setting the diffraction efficiency by the grating 11, it is easy to record a signal using only the point image of the undiffracted light without performing signal recording using these two point images.

The combination of the cylindrical lens 16 and the 4-split detector 17 is
The objective is to obtain an auto-7 orcus signal for adjusting the position of the objective lens 14 in order to accurately focus a point image.

The signal from the 4-split detector 17 is divided into two systems by a signal distribution 518, one of which is used as an autofocus signal, and the other is used for outputting and monitoring recording signals. Note that this output includes the decoding sections 5 and 6 and the information output section 7 described in FIG.

Also, during recording, a tracking signal detection detector 19.
The differential signal from 20 is in the 0FIF state.

Next, the signal reproduction system will be described.

A signal of a constant level is applied from the signal source 8 to bring the light source 9 into a state of emitting a constant amount of light. Also, as mentioned earlier, the amount of light at this time is such that the recorded magnetic domain pattern does not reverse!
J4 will be adjusted. Collimator 10. Grating 11
The light beam transmitted through the polarizing plate 12 and the optical element 13 forms three point images on the recording medium by the objective lens 14. Recording body 15
The light flux from the detector 17, 19, 20K is modulated in its polarization plane by the Kerr effect, and enters the detector 17, 19, 20K in a bright and dark modulated state in the system of the light splitting optical element 13 and the analyzer 21. Two signal systems are arranged from the detector 17, one system is an autofocus signal and the other is a reproduction signal.

Further, the signals from the detectors 19 and 20 are differentiated by a differential MP 22, and the objective lens is swung left and right using the signal to perform tracking.

Note that, due to the action of the optical element 130, a bright and dark pattern with high contrast can be detected in the reproduction system.

Note that a 772-day one-rotation element can be inserted between the optical element 13 and the recording medium 15 as a light amount adjustment means between recording and reproduction.

A Faraday rotation element is made of, for example, Y-G (yttrium, iron, garnet) crystal or glass doped with rare earth elements, and can rotate the polarization plane of a luminous flux by applying a magnetic field. I can do it. The reason for using this Faraday rotating element is as follows.

The polarization direction of the reflected light from the recording medium 15 during recording is different from the direction of one beam of reflected light subjected to Kerr rotation during reproduction. Therefore, the reflected light beam is separated from the incident light beam by the light splitting optical element 13, and the amount of light transmitted through the analyzer 21 is different.

Furthermore, during reproduction, the amount of light emitted by the light source must be lower than during recording to prevent the recorded magnetic domain pattern from reversing, so this factor also causes the amount of light that passes through the analyzer 21 to differ between recording and reproduction. different.

If the light intensity of the light beam guided through the cylindrical lens 16 to the four-split detector 17 for detecting recording signals and autofocus signals is significantly different, it becomes necessary to switch the sensitivity of the detector 17 between recording and reproduction. occurs.

Appropriate magnetic field is applied during Noah 2-day rotating element Fi recording,
To rotate the polarization plane of the recording light beam, optical element 1
3 and the analyzer 21, the amount of light entering the detector 17 is adjusted to solve the above problem.

Although this example describes a video disc, there is no need to limit it to this at all, and works can also be applied.

The conversion table T1 described in claim 1 can be realized by following the logical formula shown in Table 3.

For example, the logical formula that determines P2 in Table 3 is P2:D, AB+AB+AB, but when AB=l, A=B=i, so AB=
AB:O becomes j5 P2:D. Also IB==
When 1, A=Q and g=1, so AB,=A J3
= Q and P2=1. In this way, Table 3 is AND
, OR, and NOT only, so FAI.

(Programmable Array Logic)
It is obvious that it can be constructed as follows.

FIG. 4 shows an example of an encoder for realizing the encoding method recited in claim @1. (2) The data is inputted to the 100 4-bit shift register. 4-bit data D, D input to shift register 100
, DsD4 is subjected to the logical operations shown in Table W and 3 in the PAL circuit 101, is manually inputted in parallel to the 5-bit shift register 102, and is serially outputted as a code.

The above is an example of the first claim, but it is obvious that the conversion tables T2 to T7 described in claims 2 to 7 can also be realized based on the same idea. Therefore, descriptions of these will be omitted.

Next, an embodiment of the decoding method according to claim 8 will be described as a decoding method for the encoding method according to claim 1. The same applies to the decoding methods for the encoding methods in claims 2 to 7. Table 4 shows a conversion table for decoding, and Table 5 shows logical expressions for executing the conversion table in Table 4.

Table 4 Table 5 For example, Table 5 Logical formula for determining the glue: Z2
Z. −
When 9ft-Z, Z, = 1, z, = z, = o, so Z, (Z2÷zs) = z.

=3;0 means D and =Q. In this way, Table 5 is AN
PAL (Pr
It is obvious that it can be constructed using ograma'bleArray Logic).

FIG. 5 shows an example of Table 5. (2) The input code is input to the 5-bit shift register 103. 5-bit code input to shift register P, P, P
, P4P5 are subjected to the logical operations shown in Table 5 in the PAL circuit 104, inputted in parallel to the 4-visit register 105, and serially outputted as decoded data from (2).

Next, an embodiment of claim 9 is shown in FIG. However, in FIG. 6, B of T8 in claim 9
In THP2, l=2. The data input to the input terminal in Figure 6 (■) is 112 and 11502 4 pieces.
The data input to the bit shift register is encoded by any one of the encoding methods described in claims 1 to 7.
and 115 PAL K) converted to 1.116 and 1
It is input in parallel to 1702 5-bit craft registers. This 10-bit code is 118°119 at the same time.
It is also input to the 5-bit shift register.

The 10-bit code loaded in 118 and 119 is passed through NRZI converter 120 and converted to NRZI. The number of 1's in this NRZ-converted code is 121 CD
By 8 kakunta A, the number of 0 is also counted by 122 CD8 counter B, and the respective prices are 123 and 1.
The data is stored in register A and register B of 24. 120O
The NRZ converter is constructed as shown in FIG. 7, which includes an OFi input terminal, a js7#-J exclusive OR circuit, 138 a 1-bit delay element, and ■ an output terminal.

Calculation of CD8 of 5TEP3 in conversion table T8 is shown in Figure 6 125
12 from the contents of register A of 12'5 by the subtracter
This value is stored in the ODS register 126. Next, T8 E
ITJIiP4, but in the case of (1) to 40, the reason is (1) - day P (Oq■dq) to 1 (ii) #=#P ((3q■aq) = 1(i
iO<=-6F ((J(1■aq) = f(iJ
-=-=> It is the same value as P (Oq■aq) = 1, and this judgment is performed by the logic circuit of #1127. However, P is the value 128 in FIG. 6 and is either 1 or 0. Oq is 12
6 CD8 register MOB, (1 (l is 129
This is the MOB of the D8V register. The contents of the register are 2
Since MOB is expressed as a complement, when MOB is 1, it is a negative number, and when it is 0, it is a positive number, so the comparison of the polarities of Dfff and ODH only needs to be a comparison of cq and aq. ■ indicates exclusive OR. Based on the above four flag signals, the logic circuit of 127 will change the L of 130 to 1 if the flag 1) is on.
and set the calculation of Dlff - ODS + 1 to 15
The calculation is performed using the adder/subtractor 1 and the result of the operation is stored in the D8V register 129. , FIG. 8 shows a specific example of a circuit for generating the four flag signals mentioned above. 8TJCP as above
4 ends. Next is s'rgps, which outputs the L of the LW block 130 and the code W stored in the 5-bit shift registers 116 and 117 as many times as ■.
P, the number of 1's in LIF is determined to be even or odd using a clip of 70. [To sum up] When the number of 1's is an even number, 133 is set to 0, and when the number of 1's is odd, it is set to 1. This is 15
The initial value of the 7-rip 70-rip of 3 may be set to 0, and it may be inverted each time a 1 appears. This content is 134
It is stored in 0 batshua. Then, the exclusive OR circuit section 1351C of 165 and the exclusive # of the contents of 134 and 128
q compensation force: is taken and the result is stored in 128 P.

This completes 8TffiP5 and returns to 5TJ1iP2 again.

Table 6 shows the parameters of the encoding methods described in claims 1 to 7 when compared with the MFM and SPM methods shown in Table 2.

Table 6 Koreoshi, conventional method ij Tm1n Tw was much smaller than K, but in the 5-bokuto method, 'rw is o, a'r
This has the effect of lowering the error rate compared to the conventional method. Also, Tmax10t+x and Tmax/
It can be seen that both Tmtn are small, 3, and synchronization is extremely easy to achieve. Another great advantage of this system is that it can convert 4-bit data to 5-bit code using a simple logic circuit, making it suitable for L8 engineering. Furthermore, the method described in claim 9 is such that when DEff becomes large in BTHP4 of the T8 encoding algorithm, it is decreased or the polarity is inverted and the concatenated bit L is concatenated with the next code W. By inserting only one bit of , the absolute value of nsv can be suppressed within a finite value, which has the effect of realizing the D Free rf signal.

Further, by increasing l in 8TffP2 of the conversion table T8), it is possible to substantially maintain the parameters of the encoding system (Table 6) described in claims g1 to 7.

Further, as explained above, according to the present invention, it is possible to provide an electronic device that is highly efficient and capable of highly accurate data processing.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of an example of a conventional encoding method. Second
Figure #i is a configuration block diagram of an electronic device. FIG. 3 is a configuration diagram showing an example of a recording/reproducing system. FIG. 4 is an explanatory diagram of the encoder. FIG. 5 is a diagram showing an example of Table 5. FIG. 6 is a block diagram of the encoding configuration. Figure 7 NR
It is a block diagram of the structure of a Z-force converter. FIG. 8 is a diagram showing a specific example of a flag signal generation circuit. 1... Information source 2... Information source encoding 3... Channel encoding 4... Recording and reproducing system 5... Signaling 6... Information source decoding 7... Information output 116. 117,118,119...Shift resist applicant Canon Co., Ltd. agent Marushima "U country = T. (a) Tail 9'J I O11o 0 1 (b) M
Fl'1 method 01000101DO10DI(d)
3Pr″I method’ +oooooooo+oorit. 6th item

Claims (1)

[Claims] (1) When converting the data notation of every 4 bits of a binary data string into a code consisting of 5 bits, the following T
A binary data processing method characterized by conversion using a conversion table of 1. T1 conversion table However, 4-bit data is expressed as D2DsD4, and 5-bit code is expressed as P, F2ps:p4p5. ■A! Let D, + D2B == D, + D4. Here, + indicates OR. (2) In the above conversion table, for example, AB indicates that A and B are ANDed, and number 1 indicates NOT of A. (Engineering=0・b=1) (2) A binary data processing method characterized in that a conversion table for converting every 4-bit data of a binary data string into a 5-bit code is shown as T2 below. Also, ■ 4-bit data is represented by D2D, D4, and 5-bit code is represented by p, p, p, p4p5. ■A = D, + D2B = D, + D4. Here, + indicates OR. (2) In the above conversion table, for example, ABdA and B are ANDed, and λ indicates NOT of A. (*
=o,'6=(3) A binary data processing method characterized in that a conversion table for converting data every 4 bits of a binary data string into a 5-bit code is T3 below. However, the blank parts in the conversion table of T3 above are the claims! T1 or T2 described in s1 term or 2nd term
It is the same as the conversion table. Also, ■ 4-bit data is represented by D2D, D4, and 5-bit code is represented by P, P2P3P4P5. ■A = D, + D2B = Ds + D4. Here, + indicates OR. (2) In the above conversion table, for example, AB indicates AND of A and B, and A indicates NOT of A. (1=O, ■=1) (4) A binary data processing method characterized in that a conversion table for converting every 4 bits of a binary data string into a 5-bit code is T4 below. T4 Conversion Table However, in the T4 conversion table above, the corrupted portion is the same as the T1, T2, or T3 conversion table described in claim 1, M2, or 3. Also, 4-bit data is represented by DI D2 DI D4, and 5-bit code is represented by P, P, P, P4F. ■A: D, + D2B: D, 10D4. Here, + indicates OR. (2) In the above conversion table, for example, ABdA and B are ANDed, and X indicates NOT of A. (T=o, o=1) (5) A conversion table for converting every 4 bits of a binary data string into a 5-bit code is T5 below.
Decimal data processing method. T5 conversion table However, in the above T5 conversion table, the blank part is the T as described in claim 1, %, 2, 3, or 4.
I, T2. The conversion table is the same as that of T5 or FiT4. Also, ■ 4-bit data is represented by D2D, D4, and 5-bit code is represented by p, p, p, p4p. ■A: D, + D2B: Ds+ D4. Here, + indicates OR. (2) In the above conversion table, for example, AB indicates AND of A and B, and i indicates NOT of A. (〒=o, stone=1) (6) 2 characterized in that the conversion table for converting 4-bit data of a binary data string into a 5-bit code is the following T6.
Decimal data processing method. T6 conversion table However, in the above T6 conversion table, the blank portions are TI, T2. T3. T4. Alternatively, it may be the same as the conversion table for T5. Also, ■ 4-bit data is expressed as D2DsD45
The bit codes are expressed as p, p2P, and P4P5. ■A = D, + D2B: D, + D4. Here, + indicates OR. (2) In the above conversion table, for example, AB indicates AND of A and B, and 1 indicates NOT of A. (1=0.■=1) (7) A binary data processing method whose characteristic is that the conversion table for converting every 4 bits of a binary data string into a 5-bit code is T7 below. T7 Conversion Table However, blank parts in the above T7 conversion table are TI, T2゜T3, T4 described in Claims 1, 2, 6, 4, 5, or 6. , T5
Alternatively, it may be the same as the conversion table for T6. Also, ■ 4-bit data is represented by D2D, D45
The bit codes are expressed as p, p, psp4p5. ■A: D, + D2B: D, + D4. Here, + indicates OR. (2) In the above conversion table, for example, AB indicates AND of A and B, and τ indicates NOT of A. (T=o, o=1) (8) When decoding a code string of binary data, divide the code string into every 5 bits, and decode and transform the code divided into 5 bits into a 4-bit code. When P, (P2+P
, ) = 1, P, P3 = 1, P,
A binary data processing method characterized in that decoding is performed by determining whether P,==1 or P,(to 1)=1. Note that the 5-bit codes are p, , p2 . P,
, P4. Let it be expressed as P5. (9) A binary data processing method characterized in that the following T8 encoding algorithm is used to process binary data. 8 However, P is 0 if the number of "1"s is even, and 1 if it is odd. In addition, Hlgh of the 2-video signal obtained by converting the code W to NRZ
1evel is +I LOW '1evel is -1, and the value obtained by taking this sum is ODS. However, W is NR
It is assumed that the Z-converted 211u model number starts from LOW xevel. Further, at T8 above, sign ODS indicates the polarity of ODE. (+0r-) However, when ODS is 0, siig
n OD8 is +.