JP4666741B2 - Information rewrite count management method, information rewrite count management apparatus, use count management method, and use count storage apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an information rewrite count management method and an information rewrite count management apparatus for managing information rewrite count. The present invention also relates to a usage count management method and usage count storage device for managing the usage count of content such as software or movies.
[0002]
[Prior art]
In recent years, an advanced video compression system called the MPEG2 system and an optical disk having a large capacity near 5 GB called a DVD have been developed. By combining these two technologies, DVDs can record high-quality digital AV data for more than two hours, and video content such as movies can be enjoyed with high image quality at home. Yes.
[0003]
In addition, in the conventional movie industry, it is customary to shift the release time for each country / region. Taking Hollywood movies as an example, it is first released in the United States and half a year later in Japan and Europe. By shifting the time in this way, it will be possible to carefully select and distribute better movies around the world according to the performance in the United States, or to solve ethical problems in each country / region. It becomes possible to earn. In particular, ethical thinking depends on the country's climate, customs, and religion, and varies from country to country. Therefore, even if the content is not ethically problematic in one country, it should be noted that it may be ethically problematic in another country.
[0004]
Against this background, DVDs have a reproducible regional restriction mechanism. The DVD disc describes information on the area where the disc can be played back, and the DVD playback device stores information on the area where the disc is used.
[0005]
As long as it is only necessary to set the region information storage method in the DVD player, a switch (jumper pin, dip switch, etc.), a non-volatile memory (PROM) that can be written only once, and a writable information can be written any number of times. A non-volatile memory (EEPROM) may be used.
[0006]
However, it is inconvenient if the method can be set only once considering the case where the user is transferred to overseas or the manufacturer changes the export destination. Conversely, when the set number of times is unlimited, there is an ethical problem described above. Therefore, an upper limit is set for the number of times that can be set, and the user may reset the area if that number is reached. In order to realize this, generally, an EEPROM that can be erased and written in units of words (for example, bytes) holds information on the set area information and the set number of times.
[0007]
[Problems to be solved by the invention]
However, simply holding the area information and the set number of times with an EEPROM or the like has a weak defense against illegal modification such as removing the area restriction. For example, if a location holding EEPROM area information and the number of times of setting leaks, the number of times of setting becomes unlimited by rewriting the value. If such illegal activities are flooded, useful content will not be distributed, resulting in the loss of the benefits of many users who are doing the right thing.
[0008]
Moreover, it is meaningful to set the number of times of use (including reproduction or copying) not only for the area information as described above but also for contents such as general software or movies. For example, when the fee is determined according to the degree of the number of times the content can be used, the user can obtain the right to use the content based on the fee. Even under these circumstances, if the number of times of use is removed due to illegal modification, the content can be used indefinitely. As a result, many users who do not distribute useful content and are doing the right thing The result is a loss of profits.
[0009]
In view of the above problems, the present invention provides an information rewrite frequency management method and an information rewrite frequency device that prevent flooding of illegal activities and allow the user to rewrite the maximum number of times permitted. Also provided are a usage count management method and a usage count storage device for limiting the usage count of content.
[0010]
[Means for Solving the Problems]
  The information rewrite count management method of the present invention is an information storage area including at least one word of a non-volatile memory that can be written to each word including a plurality of bits and can be erased for each sector including a plurality of words.The information storage area is in the same sector as the initialization processing program executed first after reset, and the allowable number of rewrites is determined based on the number of words in the information storage area. , The information storage areaIn the writing step of writing information in a predetermined order, and the information written in the information storage area,TheAnd a reading step of searching for and reading the last written information within the range of the allowable number of times of rewriting.
[0011]
The method may further include an erasing step of erasing all bits of all words of the sector including the information storage area.
[0012]
The method may further include an erasing step of writing all the bits of all the words in the sector to 1.
[0014]
The predetermined order may be the order of the addresses of the words.
[0016]
The information may include area information that restricts an area where content is reproduced.
[0017]
The information rewrite frequency management method of the present invention is an information rewrite using an information storage area including at least one word of a nonvolatile memory which can be written for each word including a plurality of bits and can be erased for each sector including a plurality of words. A number of times management method, wherein an allowable number of rewrites is determined based on the number of words in the information storage area, and information is stored in the information storage area in a predetermined order.Write one or more bits in a word from 1 to 0,writingStepWhen,Of the information written in the information storage area, the documentAt least one or more bits are 0 as the last written information within the allowable number of conversionsTheWord in the information storage areaTheSearch in the given order and read the last matching word,readingStepAnd including.
[0018]
  The information rewrite frequency management method of the present invention is an information rewrite using an information storage area including at least one word of a nonvolatile memory which can be written for each word including a plurality of bits and can be erased for each sector including a plurality of words. A number of times management method, wherein an allowable number of rewrites is determined based on the number of words in the information storage area, and information is stored in the information storage area in a predetermined order.Write one bit in a word from 1 to 0,writingStepWhen,Among the information written in the information storage area, the last written information within the range of the allowable number of rewrites is searched,It is determined that information of a word in which two or more bits are 0 is invalid.readingStepWhen,Include.
[0019]
  Information rewrite frequency management method of the present inventionIsAn information rewrite count management method using an information storage area including at least one word and a rewrite count storage area of a nonvolatile memory which can be written for each word including a plurality of bits and can be erased for each sector including a plurality of words. Thus, the allowable number of rewrites is determined based on the number of words in the information storage area, and the rewrite number storage area is in the same sector as the initialization processing program that is executed first after reset, and information is stored in the information storage area. Write in a predetermined order andStores the number of writes in the information storage area in the rewrite count storage area,writingStepWhen,Including a reading step of searching for and reading the information written last in the range of the allowable number of rewrites in the information written in the information storage area.
[0021]
  An information rewrite count management device according to the present invention is a non-volatile memory that can be written for each word including a plurality of bits and can be erased for each sector including a plurality of words, and is stored in the first sector of the non-volatile memory. InSmallA non-volatile memory comprising an information storage area including at least one word;The allowable number of rewrites is determined based on the number of words in the information storage area,Information is written in a predetermined order to the words in the information storage area, and among the information written to the words in the information storage area,TheA microcomputer that searches for and reads the last written information within the allowable number of rewritesThe first sector is a sector including an address that is first executed by the microcomputer..
[0023]
The predetermined order may be the order of the addresses of the words.
[0025]
The information may include area information that restricts an area where content is reproduced.
[0026]
  An information rewrite count management device according to the present invention is a non-volatile memory that can be written for each word including a plurality of bits and can be erased for each sector including a plurality of words, and is stored in the first sector of the non-volatile memory. A non-volatile memory including an information storage area including at least one word, and an allowable number of rewrites based on the number of words in the information storage area, and writing information in words in the information storage area in a predetermined order, Among the information written in the word of the information storage area, a microcomputer that searches and reads the information written last within the range of the allowable number of rewrites, and a microcomputer,
  TheThe microcomputerTheWrites one or more bits in a word from 1 to 0, andTheAs the last written information within the specified allowable number of rewrites,TheA word in which at least one bit of the information storage area is 0TheSearch in a predetermined order and read the last matched word.
[0027]
  An information rewrite count management device according to the present invention is a non-volatile memory that can be written for each word including a plurality of bits and can be erased for each sector including a plurality of words, and is stored in the first sector of the non-volatile memory. A non-volatile memory including an information storage area including at least one word, and an allowable number of rewrites based on the number of words in the information storage area, and writing information in words in the information storage area in a predetermined order, A microcomputer that searches for and reads the information written last in the range of the allowable number of rewrites of the information written in the word of the information storage area,The microcomputerTheWrites one bit in a word from 1 to 0, and determines that information of a word in which two or more bits are 0 is invalidRu.
[0028]
  An information rewrite count management device according to the present invention is a non-volatile memory that can be written for each word including a plurality of bits and can be erased for each sector including a plurality of words, and is stored in the first sector of the non-volatile memory. An information storage area including at least one word inRewrite count storage area that stores the number of writes to the information storage areaThe number of rewrites allowed is determined based on the non-volatile memory and the number of words in the information storage area, information is written in a predetermined order in the words in the information storage area, and the information written in the words in the information storage area A microcomputer that searches for and reads the last written information within the allowable number of rewrites, and the rewrite number storage area is in the first sector that is first executed by the microcomputer..
[0038]
  The information rewrite frequency management device of the present invention is an information rewrite frequency management device comprising a nonvolatile memory that can be written for each word including a plurality of bits and can be erased for each sector including a plurality of words, and a microcomputer. The nonvolatile memory includes a boot area and a system area each composed of one or more sectors. The boot area includes an information storage area including at least one word. Microcomputer initialization means for initializing the microcomputer is arranged,The allowable number of rewrites is determined based on the number of words in the information storage area,The microcomputer writes information in the information storage area in a predetermined order in units of words, and stores the information in the information storage area.TheIt is characterized in that the last written information is searched and read out within the range of the allowable number of rewrites.
[0039]
The boot area may further include inspection means for inspecting the contents of the information storage area.
[0040]
The microcomputer may execute the microcomputer initialization unit immediately after the microcomputer is reset, then execute the inspection unit, and then execute the program stored in the system area.
[0041]
The boot area may further include an I / F control means for receiving a program stored in the system area from a host controller connected to the information rewrite count management apparatus.
[0042]
In the boot area, flash memory rewriting means for rewriting a program in the system area may be further arranged.
[0043]
The microcomputer may execute the microcomputer initialization unit immediately after the microcomputer is reset, and then wait for reception from a host control device connected to the information rewrite count management device.
[0044]
The microcomputer may call the boot area program from the system area program.
[0045]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0046]
(Embodiment 1)
There is a flash memory as a non-volatile memory for storing programs and data. A feature of the flash memory is that the contents can be erased in units called so-called sectors obtained by dividing the entire chip or the chip into several parts. For example, the contents can be written in units called 8-bit or 16-bit words. A sector includes a plurality of words, and a word includes a plurality of bits. In the flash memory, erasing is simplified from the word unit to the sector unit as compared with the conventional EEPROM, thereby reducing the cost per storage capacity. In a flash memory, generally, erasing is to set a bit to 1, and writing is to set a bit to 0. That is, in the flash memory, writing (bit is changed from 1 to 0) is performed in units of words, and erasing (bit is changed from 0 to 1) is performed in units of sectors.
[0047]
In the following description, a form using a flash memory will be described. In this specification, a “flash memory” is a memory space divided into sectors, which can be erased in units of sectors, and in units of words smaller than sectors. It means a writable nonvolatile memory.
[0048]
A small computing element (MPU: Micro Processor Unit, hereinafter abbreviated as a microcomputer) is designed to be executed from a program stored at a predetermined address when reset. The program placed at the above-mentioned predetermined address is an initialization processing program for the microcomputer, for example, processing that is indispensable for using the microcomputer, such as memory space wait setting, stack pointer initial value setting, and permission / prohibition setting for various interrupts Contains.
[0049]
When a flash memory is used as a program storage area of a microcomputer, there is only one sector including an address that is executed first after the microcomputer is reset. In the present specification, this sector is referred to as “first sector”. If this sector is erased, the microcomputer cannot perform initialization processing and runs out of control. Therefore, this sector has a feature that is difficult to erase, and is suitable for holding data that is not desired to be erased.
[0050]
With reference to FIG. 1, the state of bits stored when one word of the flash memory is overwritten will be described.
[0051]
When a program including an initialization processing program for a microcomputer is written into the flash memory for the first time using a dedicated writing device or the like, a predetermined area is reserved as an information storage area. At this time, the values stored in 8 bits in this area are all 1 as shown in FIG. 1A.
[0052]
Next, when data of 01111111b (subscript b indicates a binary number) is overwritten as a bit pattern in the same area as shown in FIG. 1B, 01111111b is stored.
[0053]
Next, as shown in FIG. 1C, when the data of 11010111b is further overwritten on the bit pattern obtained in FIG. 1B, 010110111b is stored. That is, the flash memory stores the logical product of the bit pattern already stored and the overwritten bit pattern.
[0054]
Similarly, when 11011111b is overwritten on the bit pattern obtained in FIG. 1B (see FIG. 1D), 01011111b is stored.
[0055]
Here, a specific example will be described in which information related to the region restriction of the device is stored in the device using the above flash memory. For example, data stored in units of words is set as (1) at least one bit is 0, and (2) invalid if there are 0 bits exceeding a predetermined number. The stored data is regional information of the device, and the device does not exist in more than one region at the same time. Therefore, for example, the apparatus sets one bit corresponding to the existing area to 0 and sets the other bits to 1. In this case, the condition (1) stored data is interpreted as invalid if only one bit is 0 and condition (2) two or more bits are 0. Therefore, in the above setting, as shown in FIG. 1D, data having two bits of 0 is interpreted as invalid (condition 2).
[0056]
As in the above setting, the area information can be stored in the apparatus. In the data obtained in FIG. 1B, when only the first bit of the word is 0, and the device stores this data, it is set that the device exists in the region A. At this time, if the content used by the device (for example, a DVD disc to be played back) also has regional information, the device existing in a certain region is checked by comparing the regional information of the device with the regional information of the content. Is determined to play the content. For example, the content 1 has data related to the area information shown in FIG. 1E (in this case, 1 word consisting of 8 bits), and corresponds to areas A to H in order from the leftmost bit of the word, and the bit “0”. Represents a reproducible region and bit “1” represents a non-reproducible region, the content 1 can be replayed by devices existing in region A, region C, and region D. If the device that reproduces the content 1 stores the data obtained in FIG. 1B, the device can reproduce the content 1. Conversely, this device cannot play content 2 having data 1010000 storing the data shown in FIG. 1F.
[0057]
In the above setting, the number of words in the area for storing information is made equal to the number of times rewriting is allowed. FIG. 2 shows a case where the number of times that rewriting is permitted (upper limit value of the number of permitted rewritings) N is 8. Hereinafter, the management method of area information is demonstrated using FIG.
[0058]
In the first sector 202 of the flash memory 201, a program area 203 containing a microcomputer initialization program and an information storage area 204 for N (= 8) words are arranged. In the present specification, the “first sector” means a sector including a program area for storing a program to be executed first when the microcomputer is reset. Therefore, when the microcomputer is reset, the program is executed from the program at the head address of 202 in the first sector. In the information storage area 204 for N words, all bits are 1 if there is no writing in this area yet. Here, the word 205 of the information storage area 204 is composed of 8 bits, and 11111111b is expressed as FFh (subscript h indicates a hexadecimal number) when expressed in hexadecimal.
[0059]
The area information is written in ascending order at the addresses of the words 205 constituting the information storage area 204 in accordance with the set order. The area information (F7h = 11110111b) set for the first time is written in the first word 206, and the area information (FBh = 11111011b) set for the second time is written in the second word 207. The area information (7Fh = 011111111b) set to “3” is written in the third word 208. When the area is reset until the number N of times when rewriting is permitted, there is no area in which the area information can be written more significantly in the information storage area 204. If the N + 1-th (9th in the present embodiment) area information exceeding the upper limit of the allowable number of rewrites is forcibly newly written (for example, in the fourth word 209), a plurality of bits become 0 (3Fh = 00111111b), Judged as invalid local information.
[0060]
To determine which information was written last, a word having at least one bit of 0 is searched in the information storage area 204 in ascending order of the address, and the last matching word is the desired information. It is. Here, by storing the address of the matched word as X, the microcomputer can read the last written information within the allowable number of rewrites.
[0061]
In order to write the information storage area 204 in ascending order of addresses in units of words, new information may be written at an address obtained by adding 1 to the address X of the last written word.
[0062]
Here, by setting that 0 information is written in only one bit in the word, one area in which devices in areas A to H exist and bit 0 are associated with 1: 1. However, as long as information related to the change of the area information is stored in the information storage area 204, more than 1 bits in the word may be 0. For example, data stored in units of words may be set as (1) at least one or more bits are 0, and (2) invalid if more than 8 bits are 0. Since the word has only 8 bits, condition (2) does not hold. With these conditions (1) and (2), all values other than FFh = 11111111b can be managed similarly.
[0063]
Further, the bit values 0 and 1 may be inverted. That is, (1) at least one or more bits are 0 in the data stored in word units. (2) If the number of bits exceeding a predetermined number is 1, it may be set as invalid. For example, when applying to the region information of the device, the device sets 1 bit corresponding to the currently existing region to 1 and the other bits to 0. In this case, only one bit of the data stored in the condition (1) is 1, and if two or more bits of the data stored in the condition (2) are 1, it is interpreted as invalid.
[0064]
FIG. 3 is a conceptual diagram of a method for managing bit-inverted area information. Hereinafter, FIG. 3 will be described. In addition, about the same structure as FIG. 2, the same number is attached | subjected and description is abbreviate | omitted.
[0065]
The area information is written in ascending order of the addresses of the words 205 constituting the information storage area 204 according to the set order. The area information set for the first time (08h = 00001000b) is written in the first word 306, and the area information set for the second time (04h = 00000100b) is written in the second word 307. The area information set to (80h = 10000000b) is written in the third word 308. If the area is reset until the number N of times when rewriting is permitted, no more area information can be written in the information storage area 204 any more. If new area information is forcibly written into the fourth word 309, all bits become 0 (00h = 00000000b), and the reproducible area cannot be increased. As a supplementary explanation, if 01h = 00000001b was originally set in the word 309, if a different bit is written with a value of 1, for example, 02h = 00000010b, it is stored as a logical sum as described with reference to FIG. Therefore, all bits are 0.
[0066]
Next, a method for managing all possible values including FFh = 11111111b will be described with reference to FIG. 4A. In addition, about the same structure as FIG. 2, the same number is attached | subjected and description is abbreviate | omitted.
[0067]
The flash memory 201 is further provided with a rewrite count storage area 410 composed of the number of bits equal to the number N (= 8) of rewrite allowed. In the rewrite count storage area 410, all bits are initialized to 1 and each time the bits are written to the information storage area 204, one bit is changed to 0.
[0068]
The area information is written in ascending order of the addresses of the words 205 constituting the information storage area 204 according to the set order. The first set area information (F7h = 11110111b) is written in the first word 206, and the most significant bit of the rewrite count storage area 410 is changed to 0 (7Fh = 0111111111b). The area information (FFh = 11111111b) set for the second time is written in the second word 207, and the second-order bit of the rewrite count storage area 410 is changed to 0 (3Fh = 001111111b). The area information (7Fh = 0111111b) set for the third time is written in the third word 208, and the third-order bit of the rewrite count storage area 410 is changed to 0 (1Fh = 00011111b). If the area is reset up to the number N of times that rewrite is permitted, there is no area in which the area information can be written any more in the information storage area 204, and all the bits in the rewrite count storage area 410 are set to 0. Indicates that there are no more possible times. As shown in FIG. 4A, even when the N + 1th writing is performed, all the bits in the rewrite count storage area 410 remain 0.
[0069]
In order to determine which information is written last, the number X of 0 bits in the rewrite count storage area is obtained, and the Xth word in the information storage area is the desired information. Therefore, the number X of 0 bits in the rewrite count storage area 410 indicates the number of times of writing in the information storage area 204. Conversely, the number Y of 1 bits in the rewrite count storage area 410 indicates the remaining number of times that data can be written to the information storage area 204.
[0070]
In order to write the information storage area in ascending order of addresses in units of words, new information may be written in the X + 1th word.
[0071]
In addition, in order to limit the number of times content such as general software is used, as shown in FIG. 4B, a usage number storage area 420 may be provided in the first sector 202 without the information storage area 204. If the use count storage area 420 has a function equivalent to the above-described rewrite count storage area 410, the use count of the content can be counted. The content 210 to be used is generally contained in the flash memory 201 as shown in FIG. 4B.
[0072]
As shown in FIG. 4B, the usage count storage area 420 may decrease as FFh (11111111b), 7Fh (01111111b), 3Fh (00111111b),. According to the number of times of use, 0 is stored in the bit pattern of the data in order from the left, and the remaining number of usable bits can be counted in descending order by reading the number of remaining 1 bits. it can. Conversely, by reading the number of 0 bits written, the number of times the content has been used can be counted in ascending order. When the use count storage area 420 reaches 00h (00000000), it cannot be used any more. If one word consisting of 8 bits is used, it is possible to count up to 8 times.
[0073]
As described above, according to the first embodiment of the present invention, attention is paid to the element characteristic of the flash memory in which the logical product of the stored value and the written value is stored when writing without erasing. The flash memory can be used as a write-once memory. Since the information storage area 204 exists in the same sector as the program area 203, when the data stored in the information storage area 204 is erased, the program area 203 is similarly erased. If the program area 203 is erased, the microcomputer is not initialized and becomes uncontrollable, so the area information can be changed only a predetermined number of times. In addition, because the microcomputer executes a program at a specific address after a reset, an area to be used as a write-once memory is placed in the sector of the flash memory that includes that address, preventing it from being erased. It can be protected so that it can only be used as a mold.
[0074]
(Embodiment 2)
Hereinafter, referring to the drawings, an embodiment of an optical disc apparatus that uses the information storage area described in the first embodiment to check whether the contents of the information storage area are correct and to operate according to the contents will be described with reference to the drawings. While explaining.
[0075]
FIG. 5 is a block diagram showing the configuration of the optical disc apparatus according to Embodiment 2 of the present invention. As shown in FIG. 5, the optical disk device 502 is connected to a host control device 501 such as a personal computer via an I / F bus 503 such as SCSI or ATAPI.
[0076]
The optical disk device 502 is copyrighted to a flash memory 508, a microcomputer 505 that controls the optical disk device 502 in accordance with a control program stored in the flash memory 508, an I / F circuit 504 that performs protocol control such as SCSI and ATAPI. Copyright protection circuit 506 that performs mutual authentication and information encryption for protection, DRAM 507 that temporarily stores data, and other circuits that perform servo control, photoelectric conversion, and signal processing of an optical pickup (not shown) 509. In the present embodiment, an optical disk device will be described as an example of the information rewrite frequency management device or the usage frequency storage device, but the present invention is not limited to the optical disk device.
[0077]
The advantage of using the flash memory 508 for storing the control program is that the control program can be updated in order to have some trouble or to comply with a newer standard. However, if the update of the control program stored in the flash memory 508 fails, there is a risk that the optical disk device 502 will be unable to be recovered.
[0078]
Therefore, by utilizing the characteristic that the flash memory 508 can be erased in units of sectors, a boot area that has the minimum functions necessary for restoration and is rewritten only at the time of shipment from the factory, and the latest control program is stored even after the shipment from the factory. Generally, it is divided into a system area to be rewritten. Based on such area division of the flash memory 508, a method of correctly managing the number of rewrites of information by detecting falsification of information or always referring to information will be described.
[0079]
FIG. 6 is a layout diagram of the flash memory 508. The area of the flash memory 508 is roughly divided into a boot area 601 and a system area 602. These areas are configured in units of sectors of the flash memory 508. Here, the boot area 601 is composed of a first sector 603 and a second sector 604, and the system area 602 is composed of a third sector 605, a fourth sector 606, and a fifth sector 607. Since the boot area 601 needs a function for restoring the optical disk device 502, a microcomputer initialization processing program 610, an I / F control processing program 611, and a flash memory rewriting processing program 612 are stored. Further, the boot area 601 includes an information storage area 615 that stores information with restrictions on the number of times of rewriting or use, a first inspection processing program 613 that inspects the contents of the information storage area 615, and a second inspection processing program 614. Is stored. The system area 602 includes a control program for the other circuit 509 and stores a system control program 616 that realizes all the functions of the optical disk device 502. Here, the first inspection processing program 613 and the second inspection processing program 614 are arranged in the first sector 603 so as not to be erased.
[0080]
FIG. 7 is a flowchart for explaining the main functions of the boot area 601. If a reset occurs such as when the microcomputer 505 is turned on, the microcomputer is initialized (step 701). It is determined whether or not the mode is to remain in the boot area 601 program (step 702). If the mode is to remain in the boot area 601 program, the process proceeds to the I / F control process (step 705). Processing branches to processing (step 703). Whether or not the mode stays in the program in the boot area 601 is specified by shorting a jumper pin or is determined by a checksum error in the system area 602 or the like. When the first inspection process for inspecting whether the contents of the information storage area 615 are correct is performed (step 703), it is determined whether the result is correct (step 704). If the result is correct, it is stored in the system area 602. Control is passed to the system control program 616, and if the result is not correct, the process branches to I / F control processing (step 705). In step 705, the control waits until a command from the host controller 501 is received, and performs an I / F control process for receiving the command. A command from the host controller 501 is discriminated (step 706). If the command is an update of the system control program, a flash memory rewrite process is performed (step 707) and the microcomputer is reset by itself. If the command is not an update of the system control program, other processing according to the command is performed (step 708), and the process waits for the command again (step 705).
[0081]
8A to 8C are diagrams for explaining the procedure of the rewriting process (corresponding to the process (step 705) to (step 707) in FIG. 7) of the system area 602 executed in the boot area 601. In FIG. 8, the same components as those in the configuration diagram of FIG.
[0082]
In FIG. 8A, the host control device 501 that has obtained the latest system control program 616 via the Internet or the like instructs the optical disc device 502 to update the system control program and sends a new system control program 616. The optical disk device 502 temporarily stores the received system control program 616 in the DRAM 507.
[0083]
In FIG. 8B, the optical disc apparatus 502 instructed to update the system control program copies the flash memory rewrite processing program 612 in the boot area 601 of the flash memory 508 to the DRAM 507. This is because when the flash memory 508 is operated to rewrite the flash memory 508, an operation for executing a program on the flash memory 508, for example, other operations including reading cannot be performed.
[0084]
In FIG. 8C, the microcomputer 505 temporarily transfers control to the flash memory rewrite processing program on the DRAM 507, and after erasing the system area 602 on the flash memory 508 according to the program, the system control program 616 on the DRAM 507 is transferred to the system area. Write to 602.
[0085]
Since the system control program 616 is open to the user, it can be said that there is a high risk of being tampered with by a malicious person. Therefore, it is obvious that the first inspection processing program 613 and the second inspection processing program 614 that inspect the contents of the information storage area 615 are also preferably arranged in the boot area 601 as in the information storage area 615. In this specification, the inspection of the contents of the information storage area is called “first inspection”, and the inspection related to the copyright of the system control program is called “second inspection”.
[0086]
FIG. 9 is a detailed flowchart of the first inspection process 703 shown in FIG. As initialization of variables, the inspection result is normally set, and the word to be inspected is set as the first word in the information storage area 615 (step 901). The next process is repeated until it is checked that there is no illegal value in any word in the information storage area 615 (step 902). It is confirmed whether the inspection word is correct (step 903). If there is an invalid value, the inspection result is abnormal (step 904), and the inspection process is terminated. If the check word is a correct value, the next word in the information storage area 615 is set as the check word (step 905). If all the words in the information storage area 615 have been checked (step 902), the check processing is performed. finish.
[0087]
As described above, the first inspection processing program 613 is arranged in the boot area 601 where the program to be processed is not easily tampered (see FIG. 6), and is executed before passing control to the system control program 616 (FIG. 7). Thus, it can be surely checked whether or not the contents of the information storage area 615 have been tampered with. Therefore, when the control is passed to the system control program 616, it can be guaranteed that the contents of the information storage area 615 are reliable.
[0088]
FIG. 10 is a flowchart showing a rough processing flow in the system area.
[0089]
When the processing is passed to the system control program 616 stored in the system area 602, it waits for an instruction from the host controller 501 and performs an I / F control process for receiving the instruction (step 1001). Branching is performed according to the type of the instruction (step 1002). If the instruction is related to copyright protection, the second inspection processing program 614 is executed so as to operate according to the contents of the information storage area 615 (step 1003). After execution, it returns to waiting for instructions again. If the instruction is not related to copyright protection, other processing incorporated in the system area is executed (step 1004), and after execution, the process returns to waiting for the instruction.
[0090]
FIG. 11 is a flowchart related to the second inspection process. First, after the control is transferred to the system control program 616, a first inspection process is performed to check whether the information storage area 615 has been tampered with (step 1101), and the result is judged (step 1102). If is not normal, the process ends without performing other processing. If the result is normal, the last recorded word is set as the current area information with reference to the information storage area 615 (step 1103), and the copyright information is related using the area information and the copyright protection circuit 506. (I.e., the second inspection process) is performed (step 1104).
[0091]
As described above, the second inspection processing program 614 is arranged in the boot area where the processing program is difficult to be tampered (see FIG. 6), and is executed after the control is transferred to the system control program 616 (see FIG. 10). ). Since the second inspection processing program 614 includes a program for controlling the copyright protection circuit that does not exist in the system control program 616 stored in the system area 602, in order to perform the processing requested by the host control device 501 The second inspection processing program 614 must be called. Therefore, it can be assured that after the processing shifts to the system control program 616, whether the contents of the information storage area 615 have been tampered with and that the copyright protection-related processing is reliably performed according to the contents of the information storage area 615.
[0092]
In the first embodiment, the value to be written to the information storage area and the order of the area to be written, the value to be written to the rewrite count storage area, and the like are examples, and are stored when written without being erased. Any method and apparatus may be used as long as the stored information is maintained by utilizing the element characteristic of the flash memory in which the logical product of the value and the written value is stored. Further, the information stored in the information storage area is not limited to the area information. Furthermore, the information storage area is arranged in the same sector as the address that the microcomputer executes first after resetting, and is not limited to the first sector of the flash memory.
[0093]
In the second embodiment, the boot area only has to include the sector including the address that is first executed by the microcomputer after reset, and the boot area is configured by the first sector and the second sector. It is not limited to being. Further, the flow of processing in the boot area shown in FIG. 7 is merely an example, and it is only necessary that the first inspection process is executed before the control is transferred to the system area. In the first inspection process shown in FIG. As long as the flowchart can check the alteration of the information storage area, any processing procedure may be used. Furthermore, in the flowchart of the second inspection process shown in FIG. 11, the purpose of performing the inspection process in conjunction with the hardware control is to make it necessary to execute the second inspection process. Therefore, any processing procedure may be used as long as this object can be achieved.
[0094]
Needless to say, the first sector described in the present embodiment includes the use count storage area described in the first embodiment and may be used as a component of the use count storage device. It goes without saying that the method described in this embodiment can be used as a method for managing the number of times content can be used and the number of times it can be used.
[0095]
【The invention's effect】
According to the information rewrite frequency management method of the present invention, paying attention to the element characteristic of the flash memory that the logical product of the stored value and the written value is stored when writing without erasing, the flash memory is write-once type It can be used as a memory. In addition, because the microcomputer is executed from a program at a specific address after resetting, an area used as a write-once memory is placed in the sector of the flash memory that includes that address, preventing it from being erased. It can be protected so that it can only be used as a mold. Furthermore, if information that stores the number of times of use is stored in the area that is prevented from being erased, the number of times of use is counted illegally by counting the number of times of use with the number of bits set to 0. You can protect against undoing actions.
[0096]
According to the information rewrite count management method of the present invention, an information storage area can be obtained by executing a program for performing an inspection process of an information storage area before being transferred to an updatable program that is placed in an area that is not easily tampered with. It is possible to reliably check whether the contents of the file have been tampered with. Therefore, when the control is transferred to the updatable program, it can be guaranteed that the contents of the information storage area are reliable.
[0097]
According to the information rewrite count management method of the present invention, the program that performs the information storage area inspection process and the process that uses the contents of the information storage area is placed in an area that is difficult to be tampered with, and control is transferred to an updatable program. Run later. The program including the checking process includes a process indispensable for performing the process requested by the host controller, and must be called up. Therefore, after the process moves to an updatable program, it is ensured that the content storage area has been tampered with and the process according to the information storage area is reliably performed.
[Brief description of the drawings]
FIG. 1A is a diagram of data stored in an erased flash memory.
FIG. 1B is a diagram of data stored in a flash memory after the first writing.
FIG. 1C is a diagram of data stored in a flash memory after a second writing.
FIG. 1D is a diagram of data stored in flash memory after another second write.
FIG. 1E is a diagram of data stored in content 1;
FIG. 1F is a diagram of data stored in a content 2;
FIG. 2 is a conceptual diagram of a method for managing write data in which one bit is 0;
FIG. 3 is a conceptual diagram of another management method of write data in which one bit is 1. FIG.
FIG. 4A is a conceptual diagram of a data management method using an information storage area and a rewrite count storage area.
FIG. 4B is a conceptual diagram of a data management method using a rewrite count storage area for storing the number of rewrites in descending order.
FIG. 5 is a block diagram showing a configuration of an optical disc apparatus.
FIG. 6 is a layout diagram of a flash memory.
FIG. 7 is a flowchart of the entire boot area program.
FIG. 8A is a procedure diagram of a first stage of processing for rewriting a system area;
FIG. 8B is a procedure diagram of a second stage of processing for rewriting a system area.
FIG. 8C is a procedure diagram of a third stage of processing for rewriting a system area.
FIG. 9 is a flowchart of first inspection processing.
FIG. 10 is a flowchart of the entire program in the system area.
FIG. 11 is a flowchart relating to second inspection processing;
[Explanation of symbols]
201 flash memory
202 first sector
203 Program area
204 Information storage area
205, 206, 207, 208, 209 words
306, 307, 308, 309 words
410 Rewrite count storage area
501 Host controller
502 Optical disk device
503 I / F bus
504 I / F circuit
505 microcomputer
506 Copyright protection circuit
507 DRAM
508 flash memory
509 Other circuits
510 Internal bus
601 Boot area
602 System area
603 1st sector
604 2nd sector
605 3rd sector
606 4th sector
607 5th sector
610 Microcomputer initialization processing program
611 I / F control processing program
612 Flash memory rewrite processing program
613 First inspection processing program
614 Second inspection processing program
615 Information storage area
616 system control program

Claims (21)

An information rewrite frequency management method using an information storage area including at least one word of a non-volatile memory which can be written for each word including a plurality of bits and can be erased for each sector including a plurality of words ,
The information storage area is in the same sector as the initialization processing program executed first after reset,
The allowable number of rewrites is determined based on the number of words in the information storage area,
A writing step for writing information in the information storage area in a predetermined order;
Among information written to the information storage area, it reads search the last written information within the said rewriting permissible number, and reading step,
Information rewrite frequency management method including.   2. The information rewrite count management method according to claim 1, further comprising an erasing step of erasing all bits of all words of a sector including the information storage area.   2. The information rewrite frequency management method according to claim 1, further comprising an erasing step of writing all bits of all words of the sector to 1.   The information rewrite count management method according to claim 1, wherein the predetermined order is an order of addresses of the words.   The information rewrite count management method according to claim 1, wherein the information includes area information that restricts an area in which content is reproduced. An information rewrite frequency management method using an information storage area including at least one word of a non-volatile memory which can be written for each word including a plurality of bits and can be erased for each sector including a plurality of words,
The allowable number of rewrites is determined based on the number of words in the information storage area,
To the information storage area, the information in a predetermined order, write one or more bits in the word from 1 to 0, and the writing step,
Among information written to the information storage area, as finally the written information within the 該書 conversion permitted number, the word of the data storage area at least one bit is 0 in the predetermined order Retrieve and retrieve the last matched word , read step ;
Information rewriting number of times management methods, including. An information rewrite frequency management method using an information storage area including at least one word of a non-volatile memory which can be written for each word including a plurality of bits and can be erased for each sector including a plurality of words,
The allowable number of rewrites is determined based on the number of words in the information storage area,
To the information storage area, the information in a predetermined order, writes one bit in the word from 1 to 0, and the writing step,
A step of reading out information written in the information storage area within the range of the allowable number of rewrites , and determining that information of a word having two or more bits of 0 is invalid ; ,
Information rewriting number of times management methods, including. An information rewrite count management method using an information storage area including at least one word and a rewrite count storage area of a nonvolatile memory which can be written for each word including a plurality of bits and can be erased for each sector including a plurality of words. And
The allowable number of rewrites is determined based on the number of words in the information storage area,
The rewrite count storage area is in the same sector as the initialization processing program executed first after reset,
A writing step of writing information in the information storage area in a predetermined order and storing the number of times of writing in the information storage area in the rewrite count storage area;
Among the information written in the information storage area, the last written information within the range of the permitted number of rewrites is retrieved and read, and a reading step;
Information rewriting number of times management methods, including. Writable each word comprising a plurality of bits, the information including a non-volatile memory erasable for each sector including a plurality of words, the first even without least in a sector one word of the nonvolatile memory A non-volatile memory comprising a storage area;
The allowable number of rewrites is determined based on the number of words in the information storage area,
The information words of the information storage area writing in a predetermined order, of the information written to a word of the information storage area, reads search the last the written information in the range of the rewriting permissible number, and a microcomputer ,
Equipped with a,
The first sector is a sector including an address that the microcomputer executes first.
Information rewrite count management device. The information rewrite count management device according to claim 9 , wherein the predetermined order is an order of addresses of the words. The information rewrite count management device according to claim 9 , wherein the information includes area information that restricts an area where content is reproduced. A non-volatile memory that is writable for each word including a plurality of bits and is erasable for each sector including a plurality of words, the information storage area including at least one word in the first sector of the non-volatile memory A non-volatile memory comprising:
The allowable number of rewrites is determined based on the number of words in the information storage area,
A microcomputer that writes information in words in the information storage area in a predetermined order and retrieves and reads the information written last in the range of the allowable number of rewrites in the information written in the word of the information storage area; ,
With
The microcomputer writes one or more bits in the word from 1 to 0, and, as a last the written information within the said predetermined rewriting permissible number, at least one of the information storage area the bit is 0 word searches in the predetermined order, reading the word that matches the last,
Information rewriting the management apparatus. A non-volatile memory that is writable for each word including a plurality of bits and is erasable for each sector including a plurality of words, the information storage area including at least one word in the first sector of the non-volatile memory A non-volatile memory comprising:
The allowable number of rewrites is determined based on the number of words in the information storage area,
A microcomputer that writes information in words in the information storage area in a predetermined order and retrieves and reads the information written last in the range of the allowable number of rewrites in the information written in the word of the information storage area; ,
With
The microcomputer writes one bit in the word 0 and 1, you determined to be invalid two or more bits of the word information is 0,
Information rewriting the management apparatus. A non-volatile memory that is writable for each word including a plurality of bits and is erasable for each sector including a plurality of words, the information storage area including at least one word in the first sector of the non-volatile memory A non-volatile memory comprising a rewrite count storage area for storing the number of times of writing in the information storage area ,
The allowable number of rewrites is determined based on the number of words in the information storage area,
A microcomputer that writes information in words in the information storage area in a predetermined order and retrieves and reads the information written last in the range of the allowable number of rewrites in the information written in the word of the information storage area; ,
With
The rewrite count storage area is in the first sector including the address that the microcomputer executes first.
Information rewriting the management apparatus. An information rewrite frequency management device comprising a non-volatile memory that can be written for each word including a plurality of bits and erasable for each sector including a plurality of words, and a microcomputer,
The nonvolatile memory includes a boot area and a system area each composed of one or more sectors,
The boot area has information storage region including at least one word,
Microcomputer initialization means for initializing the microcomputer is arranged in the boot area,
The allowable number of rewrites is determined based on the number of words in the information storage area,
The microcomputer writes information in the information storage area in a predetermined order in units of words,
Information rewrite count management apparatus characterized by reading searching for finally the written information in the range of the rewriting permitted number in the information storage area. The information rewrite count management device according to claim 15 , wherein an inspection unit that inspects the contents of the information storage area is further arranged in the boot area. The microcomputer according to claim 16 , wherein the microcomputer executes the microcomputer initialization unit immediately after the microcomputer is reset, then executes the inspection unit, and then executes a program stored in the system area. Information rewrite count management device. Wherein the boot area, the information rewriting count management from said upper control device connected to the apparatus for receiving a program to be stored in the system area I / F control means is further arranged, information rewrite count of claim 15 Management device. The information rewrite count management device according to claim 15 , wherein flash memory rewriting means for rewriting a program in the system area is further arranged in the boot area. The information rewrite according to claim 15 , wherein the microcomputer executes the microcomputer initialization unit immediately after the microcomputer is reset, and then waits for reception from a host control device connected to the information rewrite count management device. Count management device. The information rewrite frequency management device according to claim 15 , wherein the microcomputer calls the boot area program from the system area program.

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