JP2007172362A - Monitoring system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a monitoring system provided with an identification function of high secrecy. <P>SOLUTION: For instance, a first control part 10 is provided in a battery pack or the like, and a second control part 11 is provided in a charger or the like. In the first control part 10, for instance, the random number value of a random number generation circuit 102 is ciphered by an inspection device or the like and the ciphered data are stored in a storage circuit 105. For instance, when determining the compatibility of the battery pack and the charger, the ciphered data are transmitted to the second control part 11. The second control part 11 deciphers the ciphered data in an arithmetic circuit 111 and returns the deciphered data to the first control part 10. The first control part 10 determines the deciphered data and the random number value in a data comparator circuit 104, defines that they are compatible and permits charging when they match and inhibits charging when they do not. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a monitoring system, and more particularly to a technique effective when applied to a monitoring system that monitors and protects charging and discharging of a battery.

  For example, a secondary battery is monitored by monitoring a voltage state of a secondary battery represented by a battery pack of a mobile phone and controlling on / off of a switch connected to the electrode of the secondary battery according to the monitoring result. Battery monitoring ICs (Integrated Circuits) that prevent excessive charging of batteries and excessive discharge from secondary batteries are widely known. Japanese Patent Application Laid-Open No. 2005-228561 discloses an apparatus that performs authenticity determination of an ink cartridge of a printer. Specifically, an amorphous magnetic body having specific magnetic characteristics is bonded to the back side of the ink cartridge, and when the ink cartridge is mounted on a printer, a signal is given to the amorphous magnetic body, and the response signal is used to determine whether the response is true or false. Make a decision. As a result, a fake ink cartridge can be detected.

Patent Document 2 discloses a semiconductor integrated circuit device that can add unique identification information to each individual semiconductor chip with a simple configuration. Specifically, for example, by using a plurality of CMOS transistors whose input and output are short-circuited in one semiconductor chip, the ethical threshold value that is the output of each CMOS transistor has a magnitude relationship according to process variations. This information is used as identification information unique to the semiconductor chip. Further, since such information is different for each semiconductor chip in one semiconductor wafer, identification information unique to each semiconductor chip can be generated. Thus, by providing unique identification information for each individual semiconductor chip, it is possible to improve the product management technology.
JP 2003-80811 A International Publication No. 02/45139 Pamphlet

  In recent years, the necessity of authenticity determination has arisen in various fields. For example, with a battery pack of a mobile phone, if a non-genuine battery pack is attached and charged, the mobile phone may be damaged or ignited. Further, for example, an ink cartridge of a printer is required to eliminate counterfeit products. Such a true / false determination function (identification function) is meaningless with a mechanism that can be easily fabricated, and preferably has high secrecy. Furthermore, when providing a function of authenticity determination for general-purpose parts such as a battery pack and an ink cartridge, it is naturally required that the cost is low.

  Therefore, an object of the present invention is to provide a monitoring system having a highly confidential identification function in view of such problems and the like. Another object of the present invention is to provide a low-cost monitoring system having an identification function. The above object and novel features of the present invention will become apparent from the description of the present specification and the accompanying drawings.

  Of the inventions disclosed in the present application, the outline of typical ones will be briefly described as follows.

  The monitoring system according to the present invention includes a first control unit and a second control unit, and is a system capable of determining suitability between the first control unit and the second control unit. The first control unit is mounted on, for example, a battery pack, and the second control unit is mounted on, for example, a charger. The first control unit is mounted on, for example, an ink cartridge, and the second control unit is mounted on, for example, a printer.

  The first control unit includes a random number generation circuit for generating a random number value, a storage circuit for storing the first data, a first communication control circuit for performing communication with the second control unit, and data comparison Circuit. On the other hand, the second control unit includes a second communication control circuit for performing communication with the first control unit, and an arithmetic circuit. Here, the first data of the storage circuit is, for example, a test device or the like that reads the random number value of the random number generation circuit and encrypts the first data in the test circuit, and is stored in the storage circuit by the test device. When determining the compatibility between the first control unit and the second control unit, the stored first data is transmitted to the second control unit, and is decoded by the arithmetic circuit of the second control unit into the second data. The second data is returned to the first control unit, and the second data and the random value are compared by the data comparison circuit of the first control unit. Since the comparison results do not match unless the encryption procedure and the decryption procedure are compatible with each other, it is possible to determine the suitability.

  As another configuration, the data comparison circuit can be omitted from the first control unit described above, and the arithmetic circuit of the second control unit can have this data comparison function. In this case, when determining the compatibility between the first control unit and the second control unit, the first data of the storage circuit and the random number value of the random number generation circuit are transmitted to the second control unit, and the arithmetic circuit of the second control unit Thus, the first data is decrypted, and the decrypted result is compared with a random value. In this case as well, the comparison results do not match unless the encryption procedure and the decryption procedure are compatible with each other.

  In such a monitoring system, it is difficult to decipher the encryption procedure and the decryption procedure, and the monitoring system has high confidentiality. The circuits included in the first control unit and the second control unit are not so large and can be realized at low cost. Further, most of these circuits can be realized by widely used circuits such as a microcomputer and a memory. Therefore, when a component such as a microcomputer is originally provided in a component on which the first control unit and the second control unit are mounted, it can be realized at a lower cost.

  If the effect obtained by a representative one of the inventions disclosed in the present application is briefly described, a monitoring system having a highly confidential identification function can be realized. In addition, a monitoring system having an identification function can be realized at low cost.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Note that components having the same function are denoted by the same reference symbols throughout the drawings for describing the embodiment, and the repetitive description thereof will be omitted.

  FIG. 1 is a block diagram showing an example of the configuration of a monitoring system according to an embodiment of the present invention. The monitoring system of FIG. 1 includes a first control unit 10 and a second control unit 11 that can communicate with each other. The first control unit 10 is provided, for example, in a battery pack of a mobile phone, and the second control unit 11 is provided, for example, in a mobile phone or a charger. For example, the first control unit 10 includes a read prohibition flag 101, a random number generation circuit 102, a test circuit 103, a data comparison circuit 104, a storage circuit 105, a communication control circuit [1] 106, and an interface circuit [1. 107 or the like. Each circuit in the first control unit 10 is formed on one semiconductor chip.

  The random number generation circuit 102 generates an N-bit random number having a unique value for each first control unit 10 (each semiconductor chip). This circuit generates eigenvalues for each semiconductor chip using, for example, a method using process variation as described in Patent Document 2. The N-bit random value generated in this way is read out by an inspection device (not shown) via the test circuit 103 when the first control unit 10 (ie, the semiconductor chip) is tested. At the time of the test, the inspection apparatus performs an operation on the N-bit random value according to a predetermined operation procedure, and stores the operation result in the storage circuit 105. This operation is so-called encryption, and is performed using four arithmetic operations (addition, subtraction, multiplication, division) or a remainder operation that are normally provided in the inspection apparatus. Then, for example, an N-bit value (first data) as a result of the calculation is stored in the memory circuit 105.

  For the memory circuit 105, for example, a nonvolatile memory such as a flash memory, a semiconductor fuse, or the like is used. At the time of the test, after the calculation result is stored in such a storage circuit 105, the reading prohibition flag 101 is set by the inspection device, and thereafter reading from the random number generation circuit 102 via the test circuit 103 (that is, external of the random number value) Reading) is disabled. The read prohibition flag 101 is, for example, 1-bit non-volatile information, and can be realized using a non-volatile memory or a semiconductor fuse. The data comparison circuit 104 determines a match / mismatch between the random number value from the random number generation circuit 102 and the data input from the outside via the communication control circuit [1] 106. The communication control circuit [1] 106 has a function of performing data communication with the second control unit 11 via the interface circuit [1] 107, a function of reading data from the storage circuit 105, and the storage circuit 105 including a nonvolatile memory. In this case, the writing function is provided.

  On the other hand, the second control unit 11 includes, for example, an arithmetic circuit 111, a communication control circuit [2] 112, an interface circuit [2] 113, and the like. The communication control circuit [2] 112 has a function of performing data communication with the first control unit 10 via the interface circuit [2] 113, a function of performing data transmission / reception with the arithmetic circuit 111, and the like. The arithmetic circuit 111 performs an operation on the data (first data) of the storage circuit 105 read from the first control unit 10 according to a predetermined calculation procedure, and obtains data (second data) as a result of the operation. Transmit to the communication control circuit [2]. This calculation is so-called decryption, and is processing for returning the data that has been calculated (encrypted) by the above-described inspection apparatus to the original data.

  Next, an outline of the operation will be described. First, when the first control unit 10 (for example, a battery pack) is attached to the second control unit 11 (for example, a charger), a command from the charger side to the battery pack side (or from the battery pack side to the charger side) Data in the battery pack side storage circuit 105 is read out via the interface circuits 107 and 113 to the charger side. On the charger side, the read data is decrypted using the arithmetic circuit 111. Then, the decrypted data is transmitted to the battery pack side (first control unit 10) via the interface circuits 113 and 107.

  The decrypted data transmitted to the first control unit 10 is sent to the data comparison circuit 104 via the communication control circuit [1] 106, and is compared with the random number value of the random number generation circuit 102 by the data comparison circuit 104. The If the decryption procedure in the arithmetic circuit 111 of the first control unit 11 is correct (that is, if the decryption procedure is correct according to the encryption procedure by the above-described inspection apparatus), the decrypted data and the random number value match. It will be. In this case, it is determined that the battery pack and the charger are compatible. On the other hand, if the decoding procedure is wrong, the results of the data comparison circuit 104 are inconsistent, and it is determined that the battery pack and the charger are not compatible.

  When such a configuration is used, the first control unit 10 side can identify the suitability between itself and the second control unit 11 with the first control unit 10 side as a main body, and also performs true / false determination of the suitability. It becomes possible. That is, for example, when the battery pack is installed in the charger, the battery pack itself recognizes that it does not conform to the standard of the charger and stops the power supplied from the charger itself. Makes it possible to determine that the charger is fake. At this time, the monitoring system of FIG. 1 does not determine that there is compatibility unless the correspondence between the encryption procedure and the decryption procedure matches. In other words, as long as the encryption procedure or the decryption procedure is not leaked to a third party, it is possible to prevent a counterfeit product (which corresponds to a charger here). Here, since the encryption procedure is a process by the inspection apparatus, it is impossible to decrypt it from the component (that is, the first control unit 10). If the data of the memory circuit 105 and the random number generation circuit 102 are compared, there is a possibility that the encryption procedure can be decrypted. However, since the random number generation circuit 102 cannot read after the test, this possibility Nor.

  Further, since the first control unit 10 encrypts the random number value, the value after the encryption is different for each first control unit 10. If encryption is performed on a certain fixed value, the encrypted value is a value common to all the first control unit 10, and thus when the common value is found accidentally. Problems arise. However, when the random number value is used, the effect of such an accidental discovery only affects one part, and it does not matter so much. On the other hand, the decoding procedure can be deciphered from the arithmetic circuit 111, but since the arithmetic circuit 111 is usually realized by a microcomputer or the like, it is practically impossible to decipher the decoding procedure from the parts. I can say that. As described above, a monitoring system having high confidentiality can be realized.

  Furthermore, the monitoring system of FIG. 1 does not require many circuits. In practice, each of the parts to which the first control unit 10 and the second control unit 11 are originally provided has a circuit, Many parts of each circuit in FIG. 1 can be used together. Therefore, a low-cost monitoring system can be realized.

  FIG. 2 is a block diagram showing an example of another configuration in the monitoring system according to the embodiment of the present invention. The monitoring system shown in FIG. 2 includes a first control unit 20 and a second control unit 21 as in FIG. 1, and these can communicate with each other. The first control unit 20 is provided, for example, in a battery pack of a mobile phone, and the second control unit 21 is provided, for example, in a mobile phone or a charger. The first control unit 20 includes, for example, a random number generation circuit 202, a test circuit 203, a storage circuit 205, a communication control circuit [1] 206, an interface circuit [1] 207, and the like. Each circuit in the first control unit 20 is formed on one semiconductor chip.

  The first control unit 20 has a configuration in which the read prohibition flag 101 and the data comparison circuit 104 are omitted from the first control unit 10 of FIG. The other circuits have substantially the same functions as the circuits in FIG. On the other hand, the second control unit 21 includes an arithmetic circuit 211, a communication control circuit [2] 212, an interface circuit [2] 213, and the like, as in FIG. However, the arithmetic circuit 211 in FIG. 2 performs a match / mismatch determination process (that is, a process similar to the data comparison circuit 104 in FIG. 1) in addition to the process of the arithmetic circuit 111 in FIG. .

  In the monitoring system of FIG. 2, unlike the monitoring system of FIG. 1, a command from the second control unit 21 to the first control unit 20 (or a command from the first control unit 20 to the second control unit 21) is received. In response, both the random value of the random number generation circuit 202 of the first control unit 20 and the data (first data) of the storage circuit 205 are read. Then, the arithmetic circuit 211 decrypts the data in the storage circuit 205 in accordance with a predetermined arithmetic procedure, and compares the determination result data (second data) with the random number value (that is, expected value) of the random number generation circuit 202. To do. When the comparison results match, it is determined that the first control unit 20 and the second control unit 21 have compatibility, and when they do not match, it is determined that there is no compatibility.

  When such a configuration is used, unlike the case of FIG. 1, the second control unit 21 side identifies the compatibility between itself and the first control unit 20 with the second control unit 21 side as the main body, and the conformity thereof. It is possible to determine the authenticity of sex. That is, for example, when the first control unit 20 (for example, a battery pack) is attached to the second control unit 21 (for example, a charger), the charger side recognizes that the battery pack is out of specification and the battery pack. It is possible to stop the power supplied to the battery pack or to determine that the battery pack is a fake. At this time, as in the monitoring system of FIG. 1, the monitoring system of FIG. 2 is not determined to be compatible unless the correspondence between the encryption procedure and the decryption procedure matches.

  Here, unlike the monitoring system of FIG. 1, the monitoring system of FIG. 2 can read the value of the random number generation circuit 202 to the outside, so that the monitoring system of FIG. Is better. However, in practice, decryption is impossible unless a plurality of combinations of the values of the random number generation circuit 202 and the value of the storage circuit 205 are acquired and analyzed, so that practical secrecy can be sufficiently secured. On the other hand, in terms of cost, the monitoring system shown in FIG. 2 may require fewer circuits than the management system shown in FIG. 1, and the cost can be further reduced. Here, the arithmetic circuit 211 performs the decryption process, but instead, the random number value of the random number generation circuit 202 is encrypted by a predetermined calculation procedure, and the calculation result and the data of the storage circuit 205 are stored. It is also possible to determine suitability by comparing and determining.

  FIG. 3 is a schematic diagram illustrating a configuration example when the monitoring system of FIG. 1 is applied to a battery charge / discharge monitoring system including a battery pack and a charger. FIG. 4 is a block diagram illustrating a detailed configuration example of the monitoring IC in the monitoring system of FIG. The monitoring system in FIG. 3 includes a battery pack 30 and a charger 31. The battery pack 30 includes, for example, a lithium ion battery 302, a monitoring IC 300 connected between a power supply terminal (power supply voltage) VCC and a ground terminal (ground voltage) GND of the lithium ion battery 302, and a series connected to GND for monitoring. It includes two NMOS transistors MN1, MN2, etc. controlled by IC300. Here, each of MN1 and MN2 includes a diode between the source and the drain.

  In order to guarantee operation and noise, a fuse 301 is provided in the VCC of the lithium ion battery 302, a resistor Rvcc is provided in the VCC of the monitoring IC 300, a capacitor C1 is provided between VCC and GND, and MN1, MN2 The capacitive element C2 is provided so as to sandwich the gap. Between the charge / discharge detection terminals IDT and GND of the monitoring IC 300, a current detection resistor Ridt is provided. On the other hand, the charger 31 includes a microcomputer 311. The charger 31 can be similarly applied to a load device such as a mobile phone.

  In such a configuration, the first control unit 10 in FIG. 1 is provided in the monitoring IC 300 in FIG. 3, and the second control unit 11 in FIG. 1 is realized by the microcomputer 311 in FIG. Charging / discharging of the lithium ion battery 302 can be controlled by turning on / off MN1 and MN2, and only discharging is possible when MN1 / MN2 is on / off, and only charging is possible when MN1 / MN2 is off / on. Charging / discharging is possible when on / on, and charging / discharging is prohibited when off / off. The combination of turning on and off MN1 and MN2 is controlled by the monitoring IC 300.

  As shown in FIG. 4, the monitoring IC 300 includes a reference voltage generation circuit 401, an upper limit voltage detection circuit 402, a lower limit voltage detection circuit 403, an oscillator and timer unit 404, a control circuit 405, and a drive circuit [1] 406. [2] 407, a charger voltage detection circuit 408, a charge / discharge current detection circuit 409, and a first control unit 10a similar to FIG. Each of these components is formed on one semiconductor chip. The upper limit voltage detection circuit 402 compares the upper limit voltage preset by the reference voltage generation circuit 401 with the power supply voltage VCC, and outputs a detection signal to the control circuit 405 when VCC exceeds the upper limit voltage. . Similarly, the lower limit voltage detection circuit 403 outputs a detection signal when VCC falls below a preset lower limit voltage.

  In the oscillator and timer unit 404, for example, as described above, when VCC exceeds the upper limit voltage or the lower limit voltage, it is possible to set how long the state continues to be regarded as abnormal. The control circuit 405 receives the detection signals from the upper limit voltage detection circuit 402 and the lower limit voltage detection circuit 403 and the set time as described above in the oscillator and timer unit 404, and drives the circuits [1] 406, [2] 407. To control. The drive circuit [1] 406 drives the NMOS transistor MN1 of FIG. 3 via the discharge control terminal DCH. The drive circuit [2] 407 drives the NMOS transistor MN2 of FIG. 3 via the charge control terminal CHG. Therefore, for example, when the state where VCC exceeds the upper limit voltage continues for the set time, MN1 is turned on and MN2 is turned off to allow only discharge. For example, when the state where VCC is lower than the lower limit voltage continues for a set time, MN1 is turned off and MN2 is turned on to allow only charging.

  When the voltage of VCC is extremely large, the charger voltage detection circuit 408 drives MN2 off via the control circuit 405 and the drive circuit [2] 407, and stops charging. The charge / discharge current detection circuit 409 monitors the magnitudes of the charge current and the discharge current via the charge / discharge detection terminal IDT, and if this is excessive, the control circuit 405 and the drive circuit [1] 406, [2] MN1 and MN2 are driven off via 407 to stop charging and discharging.

  As in FIG. 1, the first control unit 10a includes a read prohibition flag 101a, a random number generation circuit 102a, a test circuit 103a, a data comparison circuit 104a, a storage circuit 105a, a communication control circuit [1] 106a, The interface circuit [1] 107a is configured. The operation of each circuit is the same as in FIG. In FIG. 4, the determination result in the data comparison circuit 104a of the first control unit 10a is input to the control circuit 405. Therefore, as described in FIG. 1, for example, when the data comparison circuit 104a determines that the battery pack 30 and the charger 31 are incompatible, the control circuit 405 passes through the drive circuits [1] 406 and [2] 407. Thus, MN1 and MN2 can be driven off, and charging and discharging can be prohibited.

  The transmission / reception of the data signal between the first control unit 10a and the microcomputer 311 of the charger 31 is not particularly limited. For example, the strobe signal STRB indicating the location of the data signal, the clock signal CLK, This is performed by the data signal DATA. Of course, it is also possible to transmit and receive data with only one signal using a generally known serial communication method. In addition, here, for ease of explanation, each circuit in the first control unit 10a is individually shown, but actually, such a circuit is originally provided by the monitoring IC corresponding to the upper half of FIG. It can also be used in combination with the provided circuit. For example, when the control circuit 405 of FIG. 4 is realized by a microcomputer, the data comparison circuit 104a and the communication control circuit [1] 106a can be used together, and the read prohibition flag 101a and the storage circuit 105a are set in the timer unit 404. It can be used together with a circuit for storing information or a trimming information storage circuit (such as a semiconductor fuse) of the reference voltage generation circuit 401.

  As described above, by using the configurations of FIGS. 3 and 4, it is possible to realize a battery charge / discharge monitoring system that can determine the compatibility between the battery pack 30 and the charger 31 while having high secrecy. Furthermore, in the battery pack 30 and the charger 31, this compatibility determination can be realized with a very small number of circuits, and a low-cost battery charge / discharge monitoring system can be realized. In addition, although the example which applied the monitoring system of FIG. 1 to the charging / discharging monitoring system for batteries of FIG. 3 was demonstrated here, of course, the monitoring system of FIG. 2 is similarly applied to the charging / discharging monitoring system for batteries of FIG. It is also possible to do. In this case, the charger 31 determines compatibility with the battery pack 30 and prohibits power supply to the battery pack 30 by the function of the charger 31 in the case of non-conformity or when the battery pack 30 is a counterfeit. Will do.

  FIG. 5 is a schematic diagram illustrating a configuration example when the monitoring system of FIG. 1 is applied to an ink monitoring system for a printer including an ink cartridge and a printer. The monitoring system in FIG. 5 includes, for example, an ink cartridge 50 that includes ink, an IC chip, and the like that can be removed from the printer, and a printer 51 to which the ink cartridge 50 is mounted. The IC chip in the ink cartridge 50 is provided with the first control unit 10b as described in FIG. The printer 51 is provided with the second control unit 11b as described with reference to FIG. The second control unit 11b can be realized by, for example, a microcomputer normally provided in the printer 51.

  As in FIG. 1, the first control unit 10b includes a read prohibition flag 101b, a random number generation circuit 102b, a test circuit 103b, a data comparison circuit 104b, a storage circuit 105b, a communication control circuit [1] 106b, The interface circuit [1] 107b is configured. Here, the storage circuit 105b may be used in combination with, for example, a memory 501 that records the remaining amount of ink that the ink cartridge 50 normally has. The ink cartridge 50 is usually provided with a communication control circuit for receiving an ink discharge command from the printer 51 including notification of the remaining amount of ink to the printer 51. The communication control circuit [1] 106b shown in FIG. 5 can be used together. The operation of each circuit in FIG. 5 is the same as that in FIG.

  By using such a configuration, it is possible to realize an ink monitoring system for a printer that can determine the compatibility between the ink cartridge 50 and the printer 51 while providing high secrecy. For example, when the ink cartridge 50 recognizes incompatibility between the ink cartridge 50 and the printer 51, the power supply to the ink cartridge 50 can be cut off to prevent a failure or the like. Although the example in which the monitoring system of FIG. 1 is applied to the ink monitoring system for printers is shown here, of course, the monitoring system of FIG. 2 can also be applied to the ink monitoring system for printers of FIG. is there. In this case, the printer 51 side determines compatibility with the ink cartridge 50 and prevents the operation of the ink cartridge 50 by the function of the printer 51 in the case of non-conformity or when the ink cartridge 50 is a counterfeit product. .

  As mentioned above, the invention made by the present inventor has been specifically described based on the embodiment. However, the present invention is not limited to the embodiment, and various modifications can be made without departing from the scope of the invention. Needless to say.

  For example, in the above description, examples of the battery monitoring system and the ink cartridge monitoring system have been described. However, the present invention is not limited to this, and can be widely applied to various parts authentication systems. For example, a system in which a first control unit is incorporated in an IC tag and a second control unit is incorporated in an IC tag reader / writer may be used. This makes it possible to realize an IC tag monitoring system that is low in cost and high in secrecy.

  The monitoring system of the present invention is a technique that is particularly useful when applied to a battery charging / discharging monitoring system and the like, and is not limited thereto, and is applicable to various parts authentication systems and parts monitoring systems including an ink cartridge monitoring system. On the other hand, it is widely applicable.

It is a block diagram which shows an example of the structure in the monitoring system by one embodiment of this invention. It is a block diagram which shows an example of another structure in the monitoring system by one embodiment of this invention. It is the schematic which shows the structural example at the time of applying the monitoring system of FIG. 1 to the charging / discharging monitoring system for batteries which consists of a battery pack and a charger. It is a block diagram which shows the detailed structural example of the monitoring IC in the monitoring system of FIG. It is the schematic which shows the structural example at the time of applying the monitoring system of FIG. 1 to the ink monitoring system for printers which consists of an ink cartridge and a printer.

Explanation of symbols

10, 10a, 10b, 20 1st control unit 11, 11b, 21 2nd control unit 101, 101a, 101b Read prohibition flag 102, 102a, 102b, 202 Random number generation circuit 103, 103a, 103b, 203 Test circuit 104, 104a 104b Data comparison circuit 105, 105a, 105b, 205 Memory circuit 106, 106a, 106b, 206 Communication control circuit 107, 107a, 107b, 207 Interface circuit 111, 111b, 211 Operation circuit 112, 112b, 212 Communication control circuit 113, 113b, 213 Interface circuit 30 Battery pack 300 Monitoring IC
301 fuse 302 lithium ion battery 31 charger 311 microcomputer 401 reference voltage generation circuit 402 upper limit voltage detection circuit 403 lower limit voltage detection circuit 404 oscillator and timer unit 405 control circuit 406, 407 drive circuit 408 charger voltage detection circuit 409 charge / discharge current Detection circuit 50 Ink cartridge 51 Printer 501 Memory Rvcc, Ridt Resistance C1, C2 Capacitance element MN1, MN2 NMOS transistor

Claims (5)

A monitoring system including a first control unit and a second control unit,
The first controller is
A random number generation circuit for generating a random value;
A storage circuit for storing first data obtained by encrypting the random number value;
A first communication control circuit that reads the first data and transmits the first data to the second control unit, and receives the second data generated by the second control unit in response to the transmission of the first data;
A data comparison circuit for determining whether or not the second data received by the first communication control circuit matches the random number value;
The second controller is
A second communication control circuit that receives the first data from the first control unit and transmits the second data to the first control unit;
An arithmetic circuit that decodes the received first data to generate the second data;
The first data is generated by an external device that is not the first control unit reading the random number value and performing the encryption, and is stored in the storage circuit by the external device. system. A monitoring system including a first control unit and a second control unit,
The first controller is
A random number generation circuit for generating a random value;
A storage circuit for storing first data obtained by encrypting the random number value;
A first communication control circuit that reads the random number value and the first data and transmits the read data to the second control unit;
The second controller is
A second communication control circuit for receiving the random number value and the first data from the first control unit;
An arithmetic circuit that decrypts the received first data and determines whether the second data obtained by the decryption matches the received random number value;
The first data is generated by an external device that is not the first control unit reading the random number value and performing the encryption, and is stored in the storage circuit by the external device. system. The monitoring system according to claim 1,
The monitoring system according to claim 1, wherein the first control unit further includes a read prohibition flag for prohibiting external reading of the random value after the external device reads the random value. The monitoring system according to claim 1 or 2,
The first control unit is provided in the monitoring chip in a battery pack including a rechargeable battery, a switch connected to an electrode of the rechargeable battery, and a monitoring chip that monitors the rechargeable battery and controls the switch,
The monitoring system, wherein the second control unit is provided in a charger that connects the battery pack and charges the rechargeable battery. The monitoring system according to claim 1 or 2,
The first control unit is provided in an IC chip included in the ink cartridge,
The monitoring system, wherein the second control unit is provided in a printer to which the ink cartridge is mounted.

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