JP2013073592A - Character code compression method and character code restoration method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To store a number of character information in a limited storage area.SOLUTION: A character code compression method includes: a first step (S101 to S110) of summarizing or reducing character types of an input character string (lot_name) expressed by m ways of basic character codes to convert the input character string into a new character string (new_lot_name) expressed by x (x<m) ways of new character codes; and a second step (steps S111 to S115) of dividing the new character string into every y characters, and adding all values calculated by multiplying the new character code of the n-th character (n=1, 2, through y) by xto generate compressed character string data (otpLotDat) of z bits for y characters (x<2).

Description

  The present invention relates to a character code compression method and a character code restoration method.

  In recent years, in the mass production process of semiconductor devices, a small-capacity non-volatile memory (such as OTPROM [One Time Programmable Read Only Memory]) is incorporated for each chip, and each chip-specific manufacturing management information (lot number, wafer number) , Coordinate information on the wafer, etc.) is required to be stored.

  As an example of the prior art related to the present invention, Patent Document 1 can be cited.

JP-A-2005-31868

  Incidentally, ASCII (American Standard Code for Information Interchange) character code is generally used when handling character information (alphanumeric characters, etc.) on a computer. However, the ASCII character code requires a storage capacity of 7 bits (or 8 bits) per character. For this reason, if a large amount of character information is stored as the manufacturing management information unique to the chip, there is a problem that the capacity of the nonvolatile memory is increased (and the cost of the semiconductor device is increased).

  In view of the above-mentioned problems found by the inventors of the present application, the present invention provides a character code compression method and a character code restoration method capable of storing a large amount of character information in a limited storage capacity. Objective.

In order to achieve the above object, the character code compression method according to the present invention integrates or reduces the character types of input character strings represented by m basic character codes, and x new characters (x <m). A first step of converting to a new character string represented by a code, and the new character string is divided into y characters, and the new character code of the nth character (where n = 1, 2 ^{,. A} second step of generating all z-multiplied values and generating z-bit (x ^y <2 ^z ) compressed character string data for ^y characters (first configuration). ing.

  In the character code compression method having the first configuration, the first step is performed on English characters (“A” to “Z”, “a” to “z”) included in the input character string. Assigning a new character code for 26 characters without distinguishing between uppercase and lowercase letters, and assigning a new character code for 10 characters to the numbers ("0" to "9") included in the input character string (A second configuration).

  In the character code compression method having the second configuration, the new character code may have a configuration (third configuration) that can take a value from 0 to 39 in decimal notation.

  In the character code compression method having the third configuration, the new character code has a configuration in which 0 is a NUL character, 1 to 26 are English characters, and 30 to 39 are numbers (fourth). (Configuration).

  In the character code compression method having the fourth configuration, the new character code may have a configuration (fifth configuration) in which 27 to 29 are symbol characters.

  The character code restoration method according to the present invention is an output character string represented by the basic character code from the compressed character string data generated by the character code compression method having any one of the first to fifth configurations. The temporary data in which the compressed character string data is stored as an initial value is divided by x and the temporary data is generated by the quotient (y-1) times, and obtained by each division. A first step of obtaining a quotient obtained by (y-1) th division as a remainder and a temporary character string represented by the new character code; and a step of converting the temporary character string into the output character string. 2 steps (sixth configuration).

  In the character code restoration method having the sixth configuration, the second step is a flow when the output character string reaches a predetermined length or when a NUL character is confirmed in the temporary character string. It may be configured to end (seventh configuration).

  A data writing apparatus according to the present invention includes a calculation unit that generates the compressed character string data from the input character string using the character code compression method having any one of the first to fifth configurations, and the calculation The storage unit stores various programs executed by the unit and a writing unit that writes the compressed character string data to an external memory (eighth configuration).

  A data writing program according to the present invention is read and executed by a computer having an arithmetic unit, a storage unit, and a writing unit, thereby causing the computer to execute a data writing program having the above-described eighth configuration. It is set as the structure (9th structure) made to function as a loading apparatus.

  The data reading device according to the present invention is also characterized in that a read unit for reading compressed character string data from an external memory and a character code decompression method comprising the sixth or seventh configuration are used to output an output character string from the compressed character string data. And a storage unit for storing various programs executed by the calculation unit (tenth configuration).

  A data reading program according to the present invention is read and executed by a computer having a reading unit, a calculation unit, and a storage unit, thereby making the computer a data reading device having the above tenth configuration. It is set as the structure to function (11th structure).

  According to the present invention, it is possible to provide a character code compression method and a character code restoration method capable of storing a large amount of character information in a limited storage capacity.

Character code compression method flowchart ASCII character code table New character code table Conceptual diagram showing a specific example of character code compression processing Flow chart of character code restoration method Conceptual diagram showing a specific example of character code restoration processing Block diagram showing a first application example Block diagram showing a second application example

<Character code compression method>
FIG. 1 is a flowchart of a character code compression method. The character code compression method illustrated in this flowchart can be embodied as a computer program described using a predetermined programming language (C language or the like), for example.

  When the flow is started, in step S101, an input character string (lot_name) represented by the ASCII character code in FIG. 2 is acquired, and then the flow proceeds to step S102. The ASCII character code is a 7-bit (or 8-bit) basic character code, and can take a value of 0 to 127 in decimal notation. As the contents of the ASCII character code, 0 to 31 and 127 are assigned to control characters (control codes), and 32 to 126 are assigned to printable characters (English characters, numbers, symbol characters).

  In step S102, various parameters are initialized (i = 0, j = 0, k = 0), and then the flow proceeds to step S103.

  In step S103, it is determined whether or not the parameter i is smaller than the character string length len of the input character string (lot_name). Here, if a yes determination is made, the flow proceeds to step S104, and if a no determination is made, the flow proceeds to step S111. Note that the character string length len can be easily obtained by using a C language strlen function or the like.

  If a YES determination is made in step S103, it is determined in step S104 whether or not the i-th character (lot_name [i]) of the input character string is a number (“0” to “9”). Here, when a yes determination is made, the flow proceeds to step S105, and when a no determination is made, the flow proceeds to step S106.

  If YES is determined in step S104, a value obtained by subtracting 18 from the ASCII code (48 to 57) corresponding to the i-th character (number ("0" to "9")) of the input character string in step S105. (Lot_name [i] -18) is calculated as a new character code (30 to 39), and this new character code (30 to 39) is temporarily stored in the register as the j-th character (new_lot_name [j]) of the new character string. The Then, after the parameter j is incremented by 1, the flow proceeds to step S110.

  If no determination is made in step S104, it is determined in step S106 whether or not the i-th character (lot_name [i]) of the input character string is an uppercase letter ("A" to "Z"). . Here, if a yes determination is made, the flow proceeds to step S107, and if a no determination is made, the flow proceeds to step S108.

  If YES is determined in step S106, 64 is subtracted from the ASCII code (65 to 90) corresponding to the i-th character (uppercase letters ("A" to "Z")) of the input character string in step S107. The value (lot_name [i] -64) is calculated as a new character code (1-26), and this new character code (1-26) is temporarily stored in the register as the j-th character (new_lot_name [j]) of the new character string. Is done. Then, after the parameter j is incremented by 1, the flow proceeds to step S110.

  If a negative determination is made in step S106, it is determined in step S108 whether or not the i-th character (lot_name [i]) of the input character string is a lowercase letter ("a" to "z"). . Here, if a yes determination is made, the flow proceeds to step S109, and if a no determination is made, the flow proceeds to step S110.

  If YES is determined in step S108, 96 is subtracted from the ASCII code (97 to 122) corresponding to the i-th character (English lowercase letters ("a" to "z")) of the input character string in step S109. The value (lot_name [i] -96) is calculated as the new character code (1-26), and this new character code (1-26) is temporarily stored in the register as the j-th character (new_lot_name [j]) of the new character string. Stored. Then, after the parameter j is incremented by 1, the flow proceeds to step S110.

  When the character code conversion process in step S105, step S107, and step S109 is completed, or when a negative determination is made in step S108, in step S110, after the parameter i is incremented by 1, the flow is started. It returns to step S103. Thereafter, the flow from step S103 to step S110 is repeated until a negative determination is made in step S103, in other words, until the conversion from the input character string (lot_name) to the new character string (new_lot_name) is completed.

  Accordingly, while the flow from step S103 to step S110 is repeated, a new character code for 10 characters (“0” to “9”) included in the input character string (lot_name) is received in step S105. 30 to 39) are assigned, and uppercase / lowercase characters are assigned in steps S107 and S109 to English letters (“A” to “Z”, “a” to “z”) included in the input character string (lot_name). A new character code (1 to 26) corresponding to 26 characters is assigned without distinction. On the other hand, the symbol characters included in the input character string (lot_name) are excluded from the new character string (new_lot_name) due to the no determination in step S108.

  That is, when the character code compression method of FIG. 1 is viewed broadly, steps S101 to S110 are performed by collecting or reducing the character types of the input character string (lot_name) represented by 128 ASCII codes, and forty ways. This corresponds to the first step of converting to a new character string (new_lot_name) represented by a new character code.

  FIG. 3 is an example of a new character code table. The new character code of this example can take 40 values (0 to 39 in decimal notation). As the contents of the new character code, 0 is assigned to a NUL character, 1 to 26 are assigned to English letters (upper case), and 30 to 39 are assigned to numbers. However, the assignment of characters in the new character code is not limited to this.

  Further, in the above-described step S101 to step S110, the operation example in which all the symbol characters are excluded from the input character string (lot_name) has been described, but the unused value (27 to 29) of the new character code is positively determined. It is possible to assign up to three kinds of symbol characters to the new character code. For example, in the case where “−” (ASCII code (45)) among the symbol characters included in the input character string (lot_name) is converted into the new character code (27), during the loop of step S103 to step S110, A step of determining whether or not the i-th character of the input character string (lot_name [i]) is “−”, and a value obtained by subtracting 18 from the ASCII code (“lot_name [ The step of calculating i] -18) as a new character code may be added. The same applies to the remaining symbol characters.

  Returning to FIG. 1, the description of the character code compression method will be continued. If a negative determination is made in step S103, 0 (corresponding to a NUL character) is input after the j-th character of the new character string (new_lot_name) in step S111, and then the flow proceeds to step S112.

  In step S112, it is determined whether or not the parameter k is smaller than the maximum data length kmax. Here, when a yes determination is made, the flow proceeds to step S113, and when a no determination is made, the flow proceeds to step S115.

  If the determination in step S112 is YES, in step S113, after the compressed character string data (otpLotDat) is generated, the flow proceeds to step S114. More specifically, in step S113, a value obtained by multiplying the 3k character (new_lot_name [3k]) of the new character string and the (3k + 1) character of the new character string by 40 (new_lot_name [3k + 1] * 40). And the value (new_lot_name [3k + 2] * 1600) obtained by multiplying the (3k + 2) character of the new character string by 1600 is added together to calculate the compressed character string data (otpLotDat). This compressed character string data (otpLotDat) is a three-character 40-digit number that uses a new character string (new_lot_name [3k], [3k + 1], [3k + 2]) for three characters as a decimal value. It can be said that it is a written value.

  In step S114, after the parameter k is incremented by 1, the flow is returned to step S112. Thereafter, the flow from step S112 to step S114 is repeated until a positive determination is made in step S112, in other words, until the conversion from the new character string (new_lot_name) to the compressed character string data (otpLotDat) is completed. .

  If the determination in step S112 is YES, in step S115, after the compressed character string data (otpLotDat) is written into the nonvolatile memory, the series of flows is terminated.

That is, when the character code compression method shown in FIG. 1 is viewed globally, steps S111 to S115 divide the new character string (new_lot_name) into three characters, and the nth character (where n = 1, 2, 3). This is equivalent to the second step of adding 16 ^n-1 values obtained by multiplying each of the new character codes and generating 16-bit compressed character string data (otpLotDat) for three characters.

  Next, the character code compression process will be specifically described with reference to FIG. FIG. 4 is a conceptual diagram showing a specific example of character code compression processing. Here, a case where “WAFER-abc (1234)” is input as the input character string (lot_name) is considered. In FIG. 1, the description has been made with an example in which the initial values of the parameters i, j, and k are 0. However, in FIG. 4, the initial value of the parameters i, j, and k is 1 for convenience of explanation. Will be described.

  The first character (lot_name [1]) to the fifth character (lot_name [5]) of the input string are all capital letters “W”, “A”, “F”, “E”, “R”. is there. Therefore, the new character code (23, 1, 6, 5, 18) obtained by subtracting 64 from each ASCII code (87, 65, 70, 69, 82) is the first character (new_lot_name [1]) of the new character string. It is temporarily stored in the register as the fifth character (new_lot_name [5]) (step S106 and step S107).

  The sixth character (lot_name [6]) of the input character string is the symbol character “−”. Therefore, the ASCII code (45) is not converted into a new character code, and the symbol character “-” is excluded from the new character string (new_lot_name) (No determination in step S108).

  The seventh character (lot_name [7]) to ninth character (lot_name [9]) of the input character string are all lowercase letters “a”, “b”, and “c”. Therefore, the new character code (1, 2, 3) obtained by subtracting 96 from each ASCII code (97, 98, 99) is the sixth character (new_lot_name [6]) to the eighth character (new_lot_name [8] of the new character string). ]) Is temporarily stored in the register (step S108 and step S109).

  The tenth character (lot_name [10]) of the input character string is the symbol character “(”. Therefore, the ASCII code (40) is not converted to the new character code, and the symbol character “(” It is excluded from the character string (new_lot_name) (No determination in step S108).

  The 11th character (lot_name [11]) to 14th character (lot_name [14]) of the input character string are all numbers “1”, “2”, “3”, and “4”. Therefore, the new character code (31, 32, 33, 34) obtained by subtracting 18 from each ASCII code (49, 50, 51, 52) is the ninth character (new_lot_name [9]) to the twelfth character of the new character string. It is temporarily stored in the register as (new_lot_name [12]) (steps S104 and S105).

  The 15th character (lot_name [15]) of the input character string is the symbol character “)”. Therefore, the ASCII code (41) is not converted into a new character code, and the symbol character “)” is excluded from the new character string (new_lot_name) (No determination in step S108).

  The 16th character (lot_name [16]) of the input character string is a NUL character, indicating the end of the input character string (lot_name). That is, the input character string (lot_name) is 15 characters (character string length len = 15). Accordingly, 0 (corresponding to a NUL character) is input from the 13th character (new_lot_name [13]) to the 16th character (new_lot_name [16]) of the new character string.

  When the conversion process from the input character string (lot_name) to the new character string (new_lot_name) is completed, the compressed character string data (otpLotDat) is generated. Specifically, first, the first character (23) of the new character string (new_lot_name), the value obtained by multiplying the second character of the new character string (new_lot_name) by 40 (1 × 40), and the new character string ( The first character value (9663) of the compressed character string data (otpLotDat) is calculated by adding all the values (6 × 1600) obtained by multiplying the third character of new_lot_name) by 1600.

  Similarly to the above, the fourth character to the sixth character (5, 18, 1), the seventh character to the ninth character (2, 3, 31), the tenth character to the twelfth character of the new character string (new_lot_name) ( 32, 33, 34) and the 13th to 15th characters (0, 0, 0) are grouped together, and the second digit value to the fifth digit value (2325, 49722) of the compressed character string data (otpLotDat). , 55752, 0).

  In the example of FIG. 4, the maximum length of the new character string (new_lot_name) is set to 16 characters. Therefore, if the new character string (new_lot_name) is divided into three characters, the 16th character (new_lot_name [16 ]) Is a surplus. In such a case, 8 bits (1 byte) are sufficient for the sixth digit of the compressed character string data (otpLotDat). As described above, each digit value of the compressed character string data (otpLotDat) is basically 16 bits (2 bytes), but all digit values need to be unified to 16 bits (2 bytes). Absent.

  According to the ASCII character code, a storage area of 7 bits × 3 characters = 21 bits (or 8 bits × 3 characters = 24 bits) is required to store character information for three characters. According to the character code compression method of the present invention, since a 16-bit storage area is sufficient, a large amount of character information can be stored in a limited storage capacity.

In the above, the number of character types x of the new character code is 40, the number of characters y integrated into one digit of the compressed character string data (otpLotDat) is 3, and the number of bits z of the compressed character string data (otpLotDat) is 16. However, the parameters x, y, and z are not limited to the above, and are arbitrarily set within a range satisfying the relational expression x ^y <2 ^z. It is possible.

  For example, when the number of character types x of the new character code is limited to 15 characters (for example, numbers “0” to “9”, English characters “A” to “C”, symbol character “−”, and NUL character). If so, the number of characters y integrated into one digit of 16-bit compressed character string data (otpLotDat) can be expanded to four.

That is, the character code compression method according to the present invention, more conceptually, summarizes or reduces the character types of the input character string (lot_name) represented by m basic character codes (ASCII character codes in the previous example). The first step of converting to a new character string (new_lot_name) represented by x new (where x <m) new character codes and the new character string (new_lot_name) are separated into y characters, and the nth character (however, n = 1, 2,..., y) are all added to each of the values obtained by multiplying ^xn−1 , respectively, and z characters (where x ^y <2 ^z ) of compressed character string data for ^y characters otpLotDat) to generate a second step.

<Character code restoration method>
FIG. 5 is a flowchart of the character code restoration method for restoring the output character string (lot_name) represented by the ASCII character code from the compressed character string data (otpLotDat) generated by the previous character code compression method. Note that the character code compression method exemplified in this flowchart can be embodied as a computer program described using a predetermined programming language (C language or the like), for example, as in the above-described character code compression method. is there.

  When the flow is started, after the compressed character string data (otpLotDat) is obtained in step S201, the flow proceeds to step S202.

  In step S202, after initialization of various parameters (i = 0, k = 0), the flow proceeds to step S203.

  In step S203, it is determined whether or not the parameter k is smaller than the maximum data length kmax. Here, if a yes determination is made, the flow proceeds to step S204, and if a no determination is made, the flow proceeds to step S209.

  In step S204, after the k-th digit value (otpLotDat [k]) of the compressed character string data is stored in the register as temporary data (dt), the flow proceeds to step S205.

  In step S205, the remainder (dt% 40) obtained by dividing the temporary data (dt) by 40 is stored in the register as the 3k character (tmp_lot_name [3k]) of the temporary character string, and the quotient (dt / 40) is the new temporary data. After being stored in the register as data (dt), the flow proceeds to step S206.

  In step S206, the remainder (dt% 40) obtained by dividing the temporary data (dt) by 40 is stored in the register as the (3k + 1) th character (tmp_lot_name [3k + 1]) of the temporary character string, and the quotient (dt / 40 ) Is stored in the register as new temporary data (dt), the flow proceeds to step S207.

  In step S207, the temporary data (dt) itself is stored in the register as the (3k + 2) th character (tmp_lot_name [3k + 2]) of the temporary character string, and then the flow proceeds to step S208.

  In step S208, after the parameter k is incremented by 1, the flow returns to step S203. Thereafter, the flow of steps S203 to S208 is repeated until a negative determination is made in step S203, in other words, until the conversion from the compressed character string data (otpLotDat) to the temporary character string (tmp_lot_name) is completed. .

  That is, when the character code restoration method of FIG. 5 is viewed globally, in steps S201 to S208, compressed character string data (otpLotDat [k]) is stored as an initial value every time the parameter k is incremented. Division of temporary data (dt) by 40 and generation of temporary data (dt) by quotient (dt / 40) (overwriting) are repeated twice, and the remainder obtained by each division and the second division are obtained. This corresponds to the first step of acquiring the obtained quotient as a temporary character string (tmp_lot_name [3k, 3k + 1,3K + 2]).

  If no determination is made in step S203, it is determined in step S209 whether or not the parameter i is smaller than the maximum character string length imax. Here, when a yes determination is made, the flow proceeds to step S210, and when a no determination is made, a series of flows is ended.

  If YES is determined in step S209, in step S210, whether or not the new character code corresponding to the i-th character (tmp_lot_name [i]) of the temporary character string is included in the range of 1 to 26 is rephrased. For example, it is determined whether or not the i-th character (tmp_lot_name [i]) of the temporary character string is an English character. If the determination is yes, the flow proceeds to step S211. If the determination is no, the flow proceeds to step S212.

  If YES is determined in step S210, a value (tmp_lot_name [i] +64) obtained by adding 64 to the new character code (1-26) corresponding to the i-th character of the temporary character string is ASCII characters in step S211. Code (65 to 90; uppercase letters “A” to “Z”), and this ASCII character code is temporarily stored in the register as the i-th character (lot_name [i]) of the output character string. Then, after the parameter i is incremented by 1, the flow returns to step S209. In addition, what is necessary is just to set the value added to new character code (1-26) to 96, when making the alphabetic character contained in an output character string (lot_name [i]) into a small letter.

  If a negative determination is made in step S210, in step S212, whether or not the new character code corresponding to the i-th character (tmp_lot_name [i]) of the temporary character string is included in the range of 30 to 39 is rephrased. For example, it is determined whether or not the i-th character (tmp_lot_name [i]) of the temporary character string is a number. Here, if a yes determination is made, the flow proceeds to step S213, and if a no determination is made, the flow proceeds to step S214.

  If YES is determined in step S212, a value (tmp_lot_name [i] +18) obtained by adding 18 to the new character code (30 to 39) corresponding to the i-th character of the temporary character string is ASCII characters in step S213. The code is calculated as a code (48 to 57; numerals “0” to “9”), and this ASCII character code is temporarily stored in the register as the i-th character (lot_name [i]) of the output character string. Then, after the parameter i is incremented by 1, the flow returns to step S209.

  When a negative determination is made in step S212, 0 (corresponding to a NUL character) is input to the i-th character (lot_name [i]) of the output character string in step S214, and then a series of flows is terminated. In this way, if the NUL character is input as the terminal character of the output character string (lot_name), when the output character string (lot_name) is handled in the subsequent processing, the terminal position (character string length) can be easily set. It becomes possible to recognize.

  That is, when the character code restoration method of FIG. 5 is viewed globally, steps S209 to S214 correspond to a second step of converting a temporary character string (tmp_lot_name) into an output character string (lot_name). Note that the second step is when the output character string (lot_name) reaches a predetermined length (imax) (when a YES determination is made in step S209) or when a NUL character is confirmed in the temporary character string (tmp_lot_name) (step The flow is terminated at the time of no determination in S212.

  Next, the character code restoration process will be specifically described with reference to FIG. FIG. 6 is a conceptual diagram showing a specific example of character code restoration processing. Here, consider a case where “WAFERABC 1234” is restored as the output character string (lot_name). In FIG. 5, the example in which the initial values of the parameters i and k are set to 0 has been described. However, in FIG. 6, the initial value of the parameters i and k is set to 1 for convenience of explanation. Give an explanation.

  In the conversion process from the compressed character string data (otpLotDat) to the temporary character string (tmp_lot_name), first, the remainder (23) obtained by dividing the first digit value (9663) of the compressed character string data by 40 is one character of the temporary character string. Obtained as the first item (tmp_lot_name [1]), and the quotient (241) is stored as temporary data. Further, the remainder (1) obtained by dividing the temporary data (241) by 40 is acquired as the second character (tmp_lot_name [2]) of the temporary character string, and the quotient (6) becomes the third character (tmp_lot_name [ 3]) (first round of steps S203 to S208).

  Next, the remainder (5) obtained by dividing the second digit value (2325) of the compressed character string data by 40 is obtained as the fourth character (tmp_lot_name [4]) of the temporary character string, and the quotient (58) is the temporary data. Stored as Further, the remainder (18) obtained by dividing the temporary data (58) by 40 is acquired as the fifth character (tmp_lot_name [5]) of the temporary character string, and the quotient (1) is obtained as the sixth character (tmp_lot_name [ 6]) (second round of step S203 to step S208).

  Next, the remainder (2) obtained by dividing the third digit value (49722) of the compressed character string data by 40 is acquired as the seventh character (tmp_lot_name [7]) of the temporary character string, and the quotient (1243) is the temporary data. Stored as Further, the remainder (3) obtained by dividing the temporary data (1243) by 40 is acquired as the eighth character (tmp_lot_name [8]) of the temporary character string, and the quotient (31) becomes the ninth character (tmp_lot_name [ 9]) (third round of steps S203 to S208).

  Next, the remainder (32) obtained by dividing the fourth digit value (55752) of the compressed character string data by 40 is acquired as the tenth character (tmp_lot_name [10]) of the temporary character string, and the quotient (1393) is the temporary data. Stored as Further, the remainder (33) obtained by dividing the temporary data (1393) by 40 is acquired as the 11th character (tmp_lot_name [11]) of the temporary character string, and the quotient (34) is obtained as the 12th character (tmp_lot_name [ 9]) (fourth round of steps S203 to S208).

  Next, the remainder (0) obtained by dividing the fifth digit value (0) of the compressed character string data by 40 is acquired as the 13th character (tmp_lot_name [13]) of the temporary character string, and the quotient (0) is the temporary data. Stored as Further, the remainder (0) obtained by dividing the temporary data (0) by 40 is acquired as the 14th character (tmp_lot_name [14]) of the temporary character string, and the quotient (0) becomes the 15th character (tmp_lot_name [ 15]) (the fifth round of steps S203 to S208).

  Finally, the sixth digit value (0) of the compressed character string data is acquired as it is as the 16th character (tmp_lot_name [16]) of the temporary character string (not explicitly shown in FIG. 5).

  When the conversion process from the compressed character string data (otpLotDat) to the temporary character string (tmp_lot_name) is completed, the conversion process from the temporary character string (tmp_lot_name) to the output character string (lot_name) is subsequently performed.

  New character codes corresponding to the first character (tmp_lot_name [1]) to the eighth character (lot_name [8]) of the temporary character string are all included in the range of 1 to 26 (corresponding to English characters). . Therefore, ASCII character codes (87, 65, 70, 69, 82, 65, 66, 67) obtained by adding 64 to each new character code (23, 1, 6, 5, 18, 1, 2, 3) are obtained. The first character (lot_name [1]) to the eighth character (lot_name [8]) of the output character string are temporarily stored in the register (steps S210 and S211).

  On the other hand, new character codes corresponding to the ninth character (tmp_lot_name [9]) to the twelfth character (lot_name [12]) of the temporary character string are all included in the range of 30 to 39 (corresponding to numbers). Yes. Therefore, the ASCII character code (49, 50, 51, 52) obtained by adding 18 to each new character code (31, 32, 33, 34) is the ninth character (lot_name [9]) to 12 characters of the output character string. The data (lot_name [12]) is temporarily stored in the register (steps S212 and S213).

  In addition, since the 13th character (tmp_lot_name [13]) of the temporary character string is a NUL character, 0 is set as the terminal character of the output character string (lot_name) in the 13th character (lot_name [13]) of the output character string. (NUL character) is input, and a series of flows is terminated (step S214).

  Thus, according to the character code restoration method of the present invention, it is possible to restore the output character string (lot_name) from the compressed character string data (otpLotDat) generated by the above-described character code compression method.

The number of character types x of the new character code, the number of characters y integrated into one digit of the compressed character string data (otpLotDat), and the number of bits z of the compressed character string data (otpLotDat) are as described above. , X ^y <2 ^z can be arbitrarily set within a range satisfying the relational expression.

  More specifically, the character code restoration method according to the present invention is more conceptually described. The temporary data (dt) in which the compressed character string data (otpLotDat) is stored as an initial value is divided by x and its quotient (dt / x). The temporary data (dt) is generated (overwritten) by (y-1) times, and the remainder (dt% x) obtained by each division and the quotient obtained by the (y-1) th division ( dt / x) has a first step of acquiring a temporary character string (tmp_lot_name) represented by a new character code, and a second step of converting the temporary character string (tmp_lot_name) into an output character string (lot_name). It can be said.

<Application>
7A and 7B are block diagrams illustrating examples of applications to which the above-described character code compression method and character code restoration method are applied, respectively. 7A and 7B includes a computer 10 and a communication protocol conversion device 20, and in a mass production process of the semiconductor device 30, chips that have been packaged in the semiconductor device 30 ( 7) and manufacturing management information (lot number, wafer number, coordinate information on the wafer, etc.) written in the non-volatile memory for each chip for the chip (FIG. 7B) formed on the wafer 40. Read / write is performed.

  The computer 10 includes a writing / reading unit 11, a calculation unit 12, a human interface unit 13, and a storage unit 14. The computer 10 appropriately reads and executes a character code compression program and a character code restoration program stored in the storage unit 14 to execute a data writing / reading device that comprehensively controls a writing / reading operation of manufacturing management information. Function as. The computer 10 corresponds to a personal computer, a microcomputer, a product tester, or the like.

  The writing / reading unit 11 writes / reads manufacturing management information (compressed character string data) to / from a nonvolatile memory for each chip via the communication protocol conversion device 20. If communication can be performed directly between the writing / reading unit 11 and the semiconductor device 30 or the wafer 40, the communication protocol conversion device 20 can be omitted.

  The arithmetic unit 12 uses the above-described character code compression method and character code restoration method to compress / restore the manufacturing management information (that is, the conversion process from the input character string to the compressed character string data and the compressed character string data). (Conversion processing to output character string). Note that a CPU [Central Processing Unit] or the like can be suitably used as the calculation unit 12.

  The human interface unit 13 accepts an input character string when writing manufacturing management information, and outputs an output character string when reading manufacturing management information. As the human interface unit 13, a keyboard, a mouse, a touch panel, a display, a speaker, or the like can be used.

  The storage unit 14 stores various programs (including a character code compression program and a character code restoration program) executed by the calculation unit 12 in a nonvolatile manner, and is also used as a work area for various programs. As the storage unit 14, a hard disk drive, a semiconductor memory device, or the like can be used.

  As described above, in the mass production process of the semiconductor device, if the configuration is such that the character code of the manufacturing management information stored in the nonvolatile memory for each chip is compressed / restored, a large amount of character information is stored in a limited storage capacity. It becomes possible.

  In FIGS. 7A and 7B, the application having the human interface unit has been described as an example. However, the configuration of the present invention is not limited to this, and an application having no human interface unit may be used. is assumed. For example, when the lot data is input by humans at the time of data writing, the above-mentioned human interface part is required. However, the lot data can be displayed on the wafer, IC mark, packaging label, barcode, etc. However, if there is a device that automatically reads them, the above-described human interface unit is not necessary. Also, when reading data, if it is sufficient to simply read lot data in the next step and record it in a storage area such as a hard disk drive for quality control, a human interface is not required. .

<Other variations>
In the above description, the configuration in which the character code of the manufacturing management information stored in the nonvolatile memory for each chip is compressed / restored in the mass production process of the semiconductor device has been described as an example. However, the present invention is not limited to this, and the present invention can be widely applied to compression / decompression of character codes for other purposes.

  Also, by applying the character code compression method and the character code restoration method according to the present invention, it is possible to encrypt / decrypt an input character string. In that sense, the term “compression / decompression” used in this specification should not be interpreted narrowly but as a broad concept including “encryption / decryption”. is there.

  A feature of the present invention is that both compression / decompression is processed in two steps. In the embodiment, an example is shown in which all character strings are processed for each step. A configuration in which two-step processing is performed every time is also conceivable.

  The present invention can process both fixed-length and variable-length character strings, and the processing of NUL characters can be omitted for fixed-length character strings.

  As described above, various technical features disclosed in the present specification can be variously modified within the scope of the technical creation in addition to the above-described embodiment. That is, the above-described embodiment should be considered as illustrative in all points and not restrictive, and the technical scope of the present invention is not limited to the description of the above-described embodiment. It is to be understood that all modifications that come within the meaning and range of meaning of the claims are embraced by the claims.

  The character code compression method and the character code restoration method according to the present invention are used as a technique for realizing a reduction in the capacity of a nonvolatile memory for storing chip-specific manufacturing management information, for example, in a mass production process of a semiconductor device. Is possible.

DESCRIPTION OF SYMBOLS 10 Computer 11 Writing / reading part 12 Operation part 13 Human interface part 14 Memory | storage part 20 Communication protocol converter 30 Semiconductor device 40 Wafer

Claims (11)

a first step of consolidating or reducing character types of input character strings represented by m basic character codes and converting them into new character strings represented by x new character codes (where x <m);
The new character string is divided into y characters, and the new character code of the nth character (where n = 1, 2,..., Y) is multiplied by ^xn−1 to add all the values. a second step of generating z-bit (where x ^y <2 ^z ) compressed character string data;
A character code compression method characterized by comprising: The first step includes
Assigning a new character code for 26 characters without distinguishing between uppercase and lowercase letters to English letters ("A" to "Z", "a" to "z") included in the input character string;
Assigning a new character code for 10 characters to numbers (“0” to “9”) included in the input character string;
The character code compression method according to claim 1, further comprising:   The character code compression method according to claim 2, wherein the new character code can take a value of 0 to 39 in decimal notation.   The character code compression method according to claim 3, wherein the new character code is 0 for NUL characters, 1-26 for English characters, and 30-39 for numbers.   The character code compression method according to claim 4, wherein the new character code is a symbol character from 27 to 29. A character code restoring method for restoring an output character string represented by the basic character code from the compressed character string data generated by the character code compressing method according to any one of claims 1 to 5. ,
Division of the temporary data in which the compressed character string data is stored as an initial value by x and generation of the temporary data by its quotient are repeated (y−1) times, and the remainder obtained by each division (y−1) ) Obtaining a quotient obtained by the second division as a temporary character string represented by the new character code;
A second step of converting the temporary character string into the output character string;
A character code restoration method comprising:   7. The character code according to claim 6, wherein the second step ends the flow when the output character string reaches a predetermined length or when a NUL character is confirmed in the temporary character string. Restoration method. An arithmetic unit that generates the compressed character string data from the input character string using the character code compression method according to any one of claims 1 to 5,
A storage unit for storing various programs executed by the calculation unit;
A writing unit for writing the compressed character string data to an external memory;
A data writing apparatus comprising:   9. A data writing device comprising: a computer having an arithmetic unit, a storage unit, and a writing unit, and causing the computer to function as the data writing device according to claim 8 by being read and executed. program. A reading unit for reading compressed character string data from an external memory;
An operation unit that generates an output character string from the compressed character string data using the character code restoration method according to claim 6 or 7,
A storage unit for storing various programs executed by the calculation unit;
A data reading device comprising:   A data reading program that causes a computer to function as the data reading device according to claim 10 by being read and executed by a computer including a reading unit, a calculation unit, and a storage unit.

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