TW201105047A - Encoder, decoder and access system with Reed-Solomon error correction mechanism - Google Patents

Abstract

An access system with a Reed-Solomon (RS) error correction mechanism is suitable for receiving a first processing signal from a data processor. The access system includes: an access controller electrically connected to a memory module for reading/writing the memory module; an encoder for performing RS encoding based on the first processing signal to obtain an encoded codeword, so as to allow the access controller to write the encoded codeword into the memory module; and a decoder for receiving a to-be-decoded codeword corresponding to the encoded codeword, wherein the to-be-decoded codeword is read by the access controller from the memory module, and the decoder performs RS decoding matched with the encoder according to the to-be-decoded codeword so as to obtain a second processing signal corresponding to the first processing signal for being transmitted to the data processor.

Description

201105047 VI. Description of the Invention: [Technical Field] The present invention relates to an access technology, and more particularly to an encoder, decoder and access having an error correction mechanism of Reed-Solomon (RS) system. [Prior Art] With the development of computer applications, in order to access a large amount of data at a high speed, the existing processor parallelizes the data to several disks for simultaneous processing, thereby shortening the waiting time. Such a multi-disk combination is called "Redundant Array of Independent Disks" (RAID). Referring to Figure 1, a RAID architecture 8 includes a controller 81 and m disks 82. When the processor 9 issues (m-Ι) pen data, the controller 81 writes each data to one of the disks 82, and calculates a test information corresponding to the data according to the parity check method. Write to the remaining disk 82. When the processor 9 wants to retrieve the (m-Ι) pen data, the controller 81 reads the data and the inspection information stored in the disk 82 again, and performs appropriate mutual exclusion or (XOR) logic judgment. Restore to approximate (m-Ι) pen data sent by the original processor 9. However, the error correction of the parity detection is not good, and it cannot be effectively restored when multiple disks 82 fail. Another RAID architecture is to use the Even-Odd code to enhance the error correction capability. It must be coded on a complete matrix basis, and the matrix size will increase with the square of the number of disks. Therefore, the buffer space requirement of this architecture is large, and the latency time is also long. On the contrary, 201105047 ignores the immediacy of the high-speed system. In addition, after the data and inspection information are stored in the disk 82, Processor 9 may want to change one of the materials. At this time, the controller 81 not only needs to read the data from the disks 82, but also recalculates a test information in conjunction with the pen change data, and finally fills in the corresponding change information and the recalculated test information. Disk 82. Also known as smaU write, if processor 9 frequently requests sporadic updates, the access speed of RAID architecture 8 is bound to be greatly reduced. SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide an encoder, decoder and access system having a Reed Solomon (RS) error correction mechanism that can be used in a small temporary storage space with a short delay time. Underneath, achieve high error correction capabilities and increase access speed. The invention has an access system with a Lie Solomon (RS) error correction mechanism, which is adapted to receive a first processing signal from a data processor, the access system comprising: an access controller, an electrical connection a memory module for reading and writing the memory module; an encoder that performs Μ encoding according to the first processed signal to obtain an encoded codeword 1 for the recording control (4) writing the encoded code to the memory a module; and - a decoder, receiving - a codeword to be decoded corresponding to the encoded codeword, and the word to be solved is (4) read by the memory module, and the solution board is based on the codeword to be decoded The ^ π encoder (4) is decoded to obtain a first process (four) corresponding to the first processed signal for transmission to the data processor. 201105047 The present invention has a Ryder Solomon (RS) error correction mechanism, which is adapted to receive a first processed signal having a complex symbol and write the encoded codeword to an address by an access guard. a memory module; the editing engineer' and the codeword encoding unit and the sporadic encoding unit respectively connected to the multi-electrode, and the multiplexer receives - displays a normal mode or a sporadic update mode x-cut mode command When the mode command displays the normal mode, the multiplexer sends the k-th of the first processing money to the (four) word encoding, and the code word encoding unit uses the generating polynomial for rs encoding to generate the Encoding a codeword, and the encoded codeword will have an n-symbol, wherein the (nk) symbol is test information related to the k-symbol, and each mode command displays a sporadic _-type, and the multi-work time will be the first- Where the symbol of the number = is sent to the sporadic coding unit, the sporadic coding unit regards the symbol as a symbol to be updated and updates the memory module related to the symbol according to zero new update Coded codeword; wherein the sporadic coding unit is The access controller from the memory module is read out of the correlation Provision Brown

The (four) test information of the codeword, and read the symbols corresponding to the symbols to be updated, to be sporadicly updated according to the symbols read. And the decoder having the error correction mechanism of the Reed Solo mRS) is adapted to receive the codeword to be decoded from the memory module, the word to be decoded has a plurality of symbols ′ and the memory module includes multiple a storage unit for respectively storing one of the symbols; the decoder includes a multiplexer, and an -uncorrecting correction unit and a known error correction unit respectively electrically connected to the multiplexer and the multi-homing H will receive - Displaying the general state or the invalid state (4) disk state message; when the disk state message shows the general state, the multiplexer decodes the 201105047 according to the RS into two unknown error correction units, and the unknown correction unit root utilizes Each root value of the generated polynomial produces a - symptom signal, to the symptoms of the dry 2 2" (4) where the symbol is stored - the symbol of the financial unit is disturbed and decoded, and the ancient cels An λ / * fr disk status message * display 1 The second processing signal of the element; when sent to a π(four)11, the multiplex 11 will leave the codeword to be decoded under the known misunderstanding of the ό海, the early error 单元, the known error correction unit will be based on the magnetic Disc know which one or two storage units are invalid, And generating a record signal according to each root value of the solution term, and then decoding the symbols of the second processed signal by the fourth shape. [Embodiment] The present invention relates to other technical contents, The features and functions will be clearly shown in the detailed description of a preferred embodiment with reference to the following drawings. / Figure 2' The present invention has the operation of the Lie Solomon (rs) error correction mechanism! The preferred embodiment of the present invention is adapted to be electrically connected between a data processor %, a memory module 4 including n storage units 41, and an encoder (decoder 2) and an access controller 3. The encoder i and the decoder 2~1 are connected to the access (4) device 3, and the access controller 3 is connected to the memory module. Preferably, the memory module 4 of the present example is a disk array (the negotiation module) The storage unit 41 refers to the disk. When the data processor 200 X is to pass a first processing signal to the memory module 4, the encoder 1 will first slant the first _ virtual brother to process the nickname for RS Encoding, and then the encoded controller 3 receives the encoded codeword and writes the codeword. 201105047 Memory module 4. When the data processor 200 wants to take out the signal from the memory module 4, the access controller 3 will first process t, with the memory minus 4 (four) corresponding codeword and then the decoder 2 for the codeword The matching signal is matched to the encoder ^rs f and sent to the data processor 200. Preferably, the device 2 causes the second processing money to be approximated to the first processing signal. 4 The included disk 41 is damaged due to the second child: = factor, then the code word read by the access controller 3 is a group of code words written before. Therefore, the present invention fills in the memory mode noise. \进仃^Encoding 'Let the encoded codeword have better anti-...this & like, then read the codec decoding from the memory module 4 to correct the error and restore as much as possible to reduce the damage of the disk 41 = use The following is an introduction of the encoder! and decoder 2 of this embodiment. When reading Figure 3' Encoder 1 is suitable for receiving the judgment from the data processor and a mode command, this mode command will reflect the data (3) want to "normal mode" or "single update (four) heart e), two "To fill in the memory module 4." The encoder 1 includes a multiplexer n and a codeword encoding unit 12 electrically connected to the multiplexer 11, and a zero-spot, . And the multiplexer 11 will, based on the mode command, the first-processing letter &< code sub-coding unit 12 or sporadic encoding unit 13. The device U knows that the mode command is "normal mode", and sends the first -where ^ sign with a W symbol (symbol) to the exhaust code unit. Next, 201105047 compiles the encoded codeword of n symbols with the generator polynomial g(x), n>k> 1. The n symbols are written to the memory module 4, and the gram code unit 12 generates one of the flops 41 according to Rs, and then the access controller 3 re-encloses the n disks 41. For example, it is assumed that the rs-coded horse used by the code-word coding unit 12 has a delay to correct this force U1'. Then when the first processed signal has the symbol ^, called ...^, the encoded code word will have the ^ character The element m 〇i will be stored in the Xg, Xi, X2 I disks 4ι. Its ^ C2 = ni2, 〇 3 = Πΐ 3 ..., Cn i = m , work W is called -1 and 4, 4 is about the call to call ~ call - 贡. Moreover, since Rs coding is a fairly straightforward technique and is well known to those of ordinary skill in the art, the composition and operation of codeword coding unit 12 is described herein. When Tian Dugong 11 knows that the mode command is "single update mode", the symbol having the first processed signal is sent to the sporadic coding unit 13. And the mode command at this time also informs which codeword stored in the memory module 4 is to be updated, and which symbol in the codeword is to be updated. Referring to Fig. 4' for convenience of explanation, the operation of the sporadic code list S and the access controller 3 will be described next on the basis of the above example of the code word encoding unit 12. Step 71: The sporadic encoding unit 13 knows according to the mode command, which position symbol of the codeword is to be changed by the processor 200 (in this example, refers to the second position, l<j<n), and causes access control The device 3 reads the stored symbol r of the code word from the third, &, a magnetic "201105047" 41. , ^, ^. The "idea" is whether or not the segment symbol is interfered by the disk 41. This is a symbol read from the disk 41, which corresponds to e_. For example • 对应 corresponds to C(). (4) The H-star coding unit 13 is pure _ non-zero element _ and receives 4 - a symbol of the processing signal, that is, a value to be updated - a non-zero 7 〇 疋 α 疋 疋 疋 疋 疋 g g g g g g The Liz's example 'can be used to view the to-be-updated symbol mj, which is ej, and (d) replaces the stored symbol rj. Step 73: The sporadic encoding unit 13 calculates a first check deviation Δ based on the non-zero element ^ position and the symbols rj, Cj' before and after the change. And a second test deviation, such as equations (1), (2).

Aj = (cy -ry. \aJ + a2j )a229 Δ〇= (cj ~rj \aJ + (aj + a2j )a230) (1) (2) Note that when Cj' replaces rj, the test information <=% + Δ. , c/q+士. Here, '^CA+M〇y<A〇 is not used because it can only be referred to by the symbol α stored in the memory module 4. As for how to derive and even, we will explain later. Step 74: The sporadic encoding unit 13 adds & and adds q to Δ1 to obtain updated values Cq, Ci of the inspection information. Step 75: The access controller 3 fills in the corresponding disks 41' by c〇,, Ci, and Cj to update Γ(), Γι, respectively, to implement sporadic update. 201105047 Therefore, it can be seen from the above process that in this embodiment, as long as the symbol mj to be updated is retrieved from the memory module 4, the symbols Γ〇, Γι, >& Star updates significantly reduce many access actions than conventional. The derivation of the test deviation ^, calculated in step 73 is as follows. First, because the error correction ability t=1, there are two non-zero elements ", so that the generator polynomial g(x) is equal to 〇, and a codeword polynomial is also made.匸 (5) is equal to 〇 'J' This code word multiple red W coefficient can reflect the symbol of the encoded stone horse c〇 ~ value (such as formula (3), (4)). If further separation of c0, Cl ' Cj, available equations (5), (6). c(a)=J>'ai=〇|=0φ2)=%α2ί=〇£=0 (3)(4) Bu 1 c0a +clQr =Cj^ + i=2,i off yc〇oru + cxaL = Cja2j + ^2« i=2Mj (5)(6)

Then, Cj is updated to Cj, = r , Λ al ^ 7 and correspondingly S 〜 ', then the equations (5) and (6) can be rewritten as follows: (.... (4) + △ 仏匕 (V.) to + he as ^ ί=2,iV jc〇'=r〇+厶., (7)(8) 10 201105047 'Then, the formula (7) is deducted (5) 'from the formula (8) deducted (6)' can be sorted out: • △〆+ △〆=△〆(9) △〇〇r0+ △〆=△〆(10) After the △G Cj'-rj, α, α2 and j are known, the equation can be solved. To get △ 〇, Δ1 :

A2j]oc 01) (12) Finally, based on the fact that all operations are based on Galois GF(2y)=GF(28), we can derive △ as in equations (1) and (2). 〇, △!. Where y represents the number of bits each symbol has, and in this case it is preferably y=8 〇

It is worth noting that during the operation of these disks 41, the probability of damage is extremely small, that is, today's Qianshan recognizes that the r〇, ri, rj of the shell are basically equivalent to the previously written C. 〇

Cj' meets the requirements of equations (3) and (4). Therefore, the present embodiment can achieve an update of the inspection information by a few symbols that have been stored in the level-a memory code, which is significantly better than the conventional technique. Decoder Referring to FIG. 5, the decoding 5|9 35 2 is adapted to receive a focus code to be decoded by the access controller 3 having a π symbol r〇~, and convert it into 201105047 with a k symbol according to the RS decoding. The second processed signal. • This code to be decoded is read from the memory module 4, so it can be regarded as a code word changed by the disk. The 曰 decoder 2 is more suitable for receiving a disk state message, including a multiplex, and an _unknown error & correcting unit 22 and an erasure correction unit 23 electrically connected to the multiplexer 21, respectively. . It is well known to those skilled in the art that the definition of an unknown is that it is not known where it is stored - the error of the disk 41 is an error, usually refers to the data caused by the damage of some magnetic regions or tracks of the disk 41. error. The known error is that where the track is stored - the disk 41 has an error, such as the inability to read data from a particular "failed" disk 41. Therefore, when the disk status message shows a "normal" state, the multiplexer 21 sends the codeword to be decoded to the error correction unit 22. #Disk status message No "failed" status. The multi-guard 21 sends the codeword to be decoded to the known error correction unit 23.前 Before describing each correction list A 22, 23 in detail, this example further defines several polynomials to represent the symbol content of the code: Ma Zi Xi Xiang C(x): Encoded codeword generated by encoder j Interference polynomial e(x): the dry words of the "encoded codewords" of the disks 41. Receive polynomial R(x): R(x)=c(1)+e(1), which can reflect “to be decoded 12 201105047 If the destructor 2 has a matching error correction capability error correction single 兀 22 can correct more t=l unknown corrections Unit 23 can correct up to 2t=2 known errors at most. t=l ' represents unknown and also represents known error. Since α and α2 are the roots of the codeword polynomial cW = k, so on the xu disk 41 M /=0砰41's payment error (error), 〇$„<„, unknown bamboo shooter correction unit 22 makes: 曰

The first symptom signal is + = ; and the first symptom nickname is S2=/?(a2)=0+e(or2)=eu.a2tt = y .X 2 . The instrument represents that the symbol stored in the xuth disk 41 is disturbed and the interference size ~ can be expressed as Yu. Therefore, 'κ% can be easily obtained. The 'unknown error correction unit 22 decodes the 帛du=ru+Yu of the first processed L number according to the symbol ru, and causes other symbols to be . ~, w=2 3,, (4) but w as. When the disk status message shows "Fail", the disk status message will also notify the known error correction unit 23: Which one or two disks 41 are damaged and lost, that is, the notification: up to two occurrences are known. The wrong position is Xu=y, Χργ, 〇a<w and Mv<w. Assuming that the interference value of the position Xu is Yu and the interference value of the position Xv is Yv, then the known error correction unit 23 will express the symptom signals Si, & as follows: 13 201105047

Si=Yu^u-hrv.aV (13) (14) For equations (13) and (14)_

^, can obtain the interference value H OS) (16) Then, the known error is more than a left to process a signal of the "quote" 23 will be decoded according to the symbol ru the second two processing signal of the first symbol And according to the symbol...

H Q 70 dv=rv+Yv, and let other (k-2) symbols A dw=rw, W=2,3,...,(n-1) but W9tu,v. ) 7" For Value> The idea is that Ge 3, right-hand disk status message only informs a location where a known error occurs, then the occurrence has been entered _ Λ 旯 旯 is early 23 can make Υ ν =〇, and two' can get the k-symbol of the second processed signal in the above manner, but: the second error correction ability t=i is used as an example to illustrate that other well-valued Bulai liters can be selected for the well. Access to the error correction capability of the system 100. In the case of § t=2, the codeword encoding unit 12 can encode according to the conventional code: ' encode the k=(n_4) symbol of the first processed signal into n symbols, 'flat code code 2t=4 symbols of the domain codeword are test information. 14 201105047 The star coding unit 13 can ^b = 4 t=4 non-zero elements, follow the description of step 73 as described above, and update the 2t=4 pieces of information when the _ is updated. . Now

On the other hand, the error correction unit 22 determines which of the two positions are disturbed based on the four non-zero elements and the four symptom ##'s, and the interference value. The known error correction unit 23 will be disturbed, a known position, and generate four 瘛-like signals associated with the non-zero elements, and then uncouple the equations to obtain the interference values of the respective positions. ° Similarly, other cases with larger t values can be analogized. Compared with the known Even-Odd encoding of the matrix, in this example, the flat coder 1 is processed by the RS encoding method—the column data (ie, k symbols), so the codeword encoding unit 12 and the sporadic encoding The temporary storage space required by unit 13 is not much, and the delay time is not long. In contrast, the browning device 2 also has the same advantages. It is to be noted that the encoder 解码 and decoder in the above embodiments can be independently accessed by the present invention. The memory module 4 can also be referred to as a network space, such as an e-mail space. When the RS code is updated, the inspection information Γ〇, Γι, and symbol ij are read from the memory module 4, and the access speed is not excessively dragged, so that the object of the present invention can be achieved. However, the above is only the preferred embodiment of the present invention, and the scope of the present invention is not limited thereto, that is, the simple equivalent changes and modifications made by the present invention in the scope of the invention and the description of the invention. All remain within the scope of the invention patent. [Simplified illustration of the embodiment]; device; star coding unit and memory

1 is a block diagram of a conventional RAID architecture. FIG. 2 is a block diagram showing the access system of the present invention. FIG. 3 is a block diagram showing the editing of the embodiment. FIG. 4 is a flowchart illustrating the embodiment. The operation of the zero take controller; and FIG. 5 is a block diagram illustrating the decoder of the embodiment

16 201105047 [Description of main component symbols] 100... •...Access system 71.........·························································· .... ...the multiplexer to update the symbol step 12... •---code subcode early element 13... •... sporadic coding unit 73......... §t calculation test deviation 2 ... .... •...Decoder Step 21... •...Multiplexer 74..... 22... •...Unknown Error Correction Unit Step 23... .... Known Error Correction Unit 75...·. Post-check 3 ....... • Access controller information and symbols 4... • Memory module step 41... • Storage unit

17

Claims (1)

201105047 VII. Patent application scope: 1. An encoder with a Reed Solomon (RS) error correction mechanism, adapted to receive a first processed signal having a complex symbol and to be encoded by an access controller The code word is written to a memory module; the encoder includes a multiplexer, and a codeword coding unit and a sporadic coding unit respectively electrically connected to the multiplexer, and the multiplexer receives a normal display a mode command of a mode or a sporadic update mode; when the mode command displays a normal mode, the multiplexer sends the k-symbol of the first processed signal to the codeword encoding unit, and the codeword encoding unit utilizes A generator polynomial performs RS coding to generate the encoded codeword, and the encoded codeword has an n-symbol, wherein the (n_k) symbol is test information related to the k-symbol, when the mode command displays a sporadic update a mode, the multiplexer sends one of the symbols of the first processed signal to the sporadic coding unit, and the sporadic coding unit regards one of the symbols as a symbol to be updated, and updates the The memory module associates the encoded Ma word associated with the symbol. The 'single splice unit is the (nk) inspection information that causes the access controller to read the associated encoded codeword from the memory module. And reading the symbols corresponding to the symbols to be updated to be sporadicly updated according to the read symbols and at least one value of the generator polynomial. 2. According to the device described in claim 1 of the scope of the patent application, the error correction of the RS code used in the coding unit of the Sheriff code can be six-recognition & - ° and t, and the number of checks is 2t. ; The sporadic coding unit is based on the generator polynomial. The root value, 18 201105047, and then adjust the zero to calculate a test deviation star coded test information value for each test information. 3. The mode command received by the encoder according to the scope of the patent application is also displayed. The j-th symbol position of the encoded codeword; 1% is located in the phase Rabbit 1 when::! The error correction capability of the Rs bat code used by the coding unit is (4) = 2, and the sporadic coding unit is based on the one of the generator polynomial, the position to be updated, and the corresponding The read symbol V of the symbol to be updated is used to update the test information from 6 to Cq', : co'= ro + (cj'~η)aj + (cj'-r 1 (α+αη decoding) The codeword is adapted to receive the codeword to be decoded to store one of the four. 4. A Reed Solomon (RS) error correction mechanism receives a plurality of symbols of a codeword to be decoded from a memory module, and the memory The module includes a plurality of storage units using symbols; the decoder includes a multiplex H, and an unknown error correction unit and a known error correction unit respectively electrically connected to the multiplexer, and the multiplexer receives a disk status message indicating a general status or a failed status; when the disk status message indicates a general status, the multiplexer sends the to-be-decoded code to the unknown error correction unit, the error correction unit according to the RS Decoding to generate at least one root value of a generator polynomial a symptom 彳 §, and then use the generated symptom signal to find out which 19 201105047 storage unit symbol is disturbed, and decode a second processing signal with multiple symbols; when the disk status message Displaying a failure state, the multiplexer sends the codeword to be decoded to the known error correction unit, and the known error correction unit knows which one or two storage units are invalid according to the disk state message, and Generating a symptom signal according to at least one root value of the generator polynomial according to RS decoding, and decoding the symbol of the second processed signal by using the generated symptom signal. 5. According to claim 4 a decoder, wherein, when the error correction capability of the RS decoding used by the error correction unit is [, a corresponding symptom signal is generated for each of the 2t root values of the generator polynomial, and which is obtained according to the symptom signals. The symbols of the t positions are interfered, and the corresponding interference values are obtained to adjust the relevant symbols. 6. The decoder according to claim 4, wherein when the unknown The error correction capability of the RS decoding used by the correction unit is 产生, a first symptom signal is generated for a first root value of the generator polynomial, and a second symptom signal is generated for a second root value of the generator polynomial; Dividing the second symptom signal by the first symptom signal to find out which cell in which the cell is stored is disturbed, and dividing the square of the first symptom signal by the second symptom signal to find the The interference value of the symbol is used to decode the corresponding symbol of the second processed signal. 7. The decoder according to claim 4, wherein the error correction of the RS decoding used by the known error correction unit The capability is 〖, and the disk state message is used to know that at most 2t symbol positions where a known error occurs. 201105047. The known error is corrected. The early element is generated according to the 2t occurrence of the known symbol position of the error. The 2t root values of the polynomial produce a corresponding symptom nickname 'and then solve the cubic program to obtain the interference value of each position to adjust the relevant symbol. 8. According to the decoding of the patent scope 4, the decoding H, the towel, when the known error correction unit uses the error correction capability of the Rs decoding, the two occurrences will be known according to the disk state message. The erroneous symbol position Xu, Xv, and a first root value α of the generator polynomial is generated to generate a first vertex signal S1, and a second root value of the generator 4 is generated to generate a second symptom Signal S2; and based on the two symptom signals, S2, find the symbol interference values Yu, Υν of the positions Xu and Χν: 9. yu = + S2 ^+v) γ - + - an access system with a Reed Solo H (RS) error correction mechanism, adapted to receive a first processed signal from a data processor and electrically connected to a § hex a module, the access system includes: an access controller electrically connecting the memory module module and group; reading and writing the memory-encoder, and performing RS coding according to the first processing Obtaining an encoded codeword for the access control system to write the encoded codeword to the memory module; and 21 201105047 a decoder receiving an m — corresponding to the encoded code The character of the word is formed, and the code to be decoded of the codeword county to be decoded is read by the access controller from the picture. The decoder will be based on this. The RS decoding of the group is concealed, and the incoming signal is matched to the encoded signal 'to be sent to the data processor. . The first part of the application system of claim 9, wherein the signal has a complex symbol, and the complex is processed by β ν , wherein the encoder includes a multiplexer, and Each of the multiplexers is electrically connected to the multiplexer with a code unit; the received code is coded by the coding unit and the sporadic code is received by the multiplexer to display the official command; the mode of the tenth or the star update mode is displayed correctly. In the ceremony, the multiplexer sends the tk symbol of the first processed signal to the encoding unit, and the codeword encoding unit uses the generated one. RS coding is performed to generate the coded codeword, and the coded codeword will be one, and f has an η symbol 兀 'where the (n_k) symbol is the test information related to the k symbol, " When the mode command displays a sporadic-reported p4 to an updated wedge, the multiplexer sends the symbol of the first-processed signal to the sporadic coding unit, and the sporadic coding unit regards the -symbol as _ Update the symbol, and update the memory module ten according to zero new Regarding the encoded codeword of the symbol; wherein 'the sporadic code list causes the access controller to read the (nk) check information of the relevant encoded codeword from the memory module and read the corresponding The symbols of the symbol are updated to be sporadically updated according to the symbols read and at least one value of the generator polynomial. 22 201105047 ιι·According to the access system described in the first application of the patent scope, - A, When the codeword coding unit uses the error correction of the RS code to be t, the number of test information is 2t; the sporadic coding unit calculates the test for each test information based on the 2t root values of the generator polynomial. Deviation, and then the value of each inspection information after the encoding of the comet. °. Order 12. According to the access system described in the first paragraph of the patent application, the mode command received by the worker also displays the symbol to be updated. Is the position of the jth symbol of the coded codeword associated with the Lu; ; § When the code of the codeword is used by the Rs, the number of symbols of the test information is (n_k)=2, #based on the Generating a polynomial α, position j :: code early - and corresponding to the update of the opening & 1 command - · new symbol. News from 4, Daixin, ., Ci.: search for education c-^ + (c / where The memory code refers to the access system described in claim 9 of the patent application scope. The RS code codeword has a plurality of groups corresponding to the coded codeword. Including a plurality of stored in the firefly-m yang a δ recall; j in the - ί is used to store the codeword to be decoded separately; the decoder includes a multiplexer, - the error correction unit disk; Connecting the multiplex i corrects the early-and-known error correction unit, and the more] 23 201105047 receives a disk status message showing the general status or the invalid status; when the disk status message shows the general status, the The processor sends the codeword to be decoded to the error correction unit, and the error correction unit respectively generates a symptom signal for at least one root value of the generator polynomial, and then uses the generated signal to find out which storage to store. The symbol of the unit is disturbed' and the second processing letter is decoded a plurality of symbols; when the far disk status message indicates a failure state, the multiplexer sends the codeword to be decoded to the known error correction unit, and the known error correction unit will according to the disk status message Knowing which one or two storage units fail, and generating a symptom signal for each of the at least one root value of the generator polynomial', and then decoding the symbols of the second processed signal by using the generated symptom signal. 14. The access system according to claim 13, wherein the error correction capability of the Rs decoding used by the error correction unit is t, which respectively generates 21 root values of the generator polynomial - corresponding The symptom signal determines which t-position symbols are interfered based on the sickness signals and finds the corresponding interference value to adjust the relevant symbols. 15. The access system according to claim 13, wherein when the error correction capability of the decoding of the decoding is RS, the error correction unit generates a first value of the generator polynomial. a first symptom k, which also generates a second symptom signal for a second value of the generator polynomial; and dividing the second symptom signal by the first symptom signal to find the storage unit The symbol is disturbed, and the square of the first symptom 24 201105047 signal is divided by the second symptom signal to obtain the interference value ' of the symbol to decode the corresponding symbol of the second processed signal. 16. The access system of claim 13, wherein the error correction capability of the RS decoding used by the known error correction unit is t, and at least 2t occurrences are known by the disk state message. Knowing the wrong symbol position; the known error correction unit generates a corresponding symptom_signal for each 2t root values of the generator polynomial according to the 2t symbol positions where the known error occurs, and then decomposed the cubic program to obtain each The interference value of the position to adjust the associated symbol. 17. The access system according to claim 13 wherein when the error correction capability of the RS decoding by the decoder is i, the known error correction unit knows that two occurrences have occurred according to the disk status message. The erroneous symbol position XU, XV 'and a first symptom value Si of the generator polynomial generates a first symptom signal Si ' and a second symptom value a 2 for the generator polynomial generates a second symptom signal &;; and based on the two symptom signals Si, S2, find the symbol interference value Yu of the position Xu, χν, Ϋν: γ = ^γ(Χν + S2 u cx 25