JP2018120578A - Circuit device, oscillation device, physical quantity measuring device, electronic apparatus, and vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a circuit device, an oscillation device, a physical quantity measuring device, an electronic apparatus, a vehicle and the like which are capable of reducing a concern for the forgery of the oscillation device or physical quantity measuring device.SOLUTION: A circuit device 100 includes an oscillation circuit 80 that generates an oscillation signal by using an oscillator XTAL, a processing unit 10 that controls the oscillation circuit 80, and an interface unit 60 that outputs authentication information to an external device 200, where the authentication information is information based on specific information on the circuit device 100 and is used to authenticate the circuit device 100.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a circuit device, an oscillation device, a physical quantity measuring device, an electronic device, a moving object, and the like.

  In a system using an oscillation device such as a real-time clock device or a physical quantity measurement device, there is a possibility of hacking due to, for example, impersonation or data tampering, and security measures against such hacking may be required.

  As a conventional technique for security measures in a real-time clock device, for example, there is a technique disclosed in Patent Document 1. In Patent Document 1, when an external device tries to access the real-time clock device, the external device transmits an access code to the real-time clock device, the real-time clock device checks the access code against the expected value, and the access code is the expected value. The real-time clock device permits access when they match, and prohibits access when they do not match.

JP 2010-225209 A

  However, in the conventional technology as described above, the oscillation device or the physical quantity measurement device can authenticate the external device, but there is a problem that it cannot cope with the possibility of impersonation of the oscillation device or the physical quantity measurement device. For example, impersonation of an oscillating device or physical quantity measuring device can be replaced with an unauthorized oscillating device or physical quantity measuring device (for example, a modified device), or an unauthorized device impersonating the oscillating device or physical quantity measuring device can be illegally transferred to an external device. Data transmission is assumed.

  According to some aspects of the present invention, it is possible to provide a circuit device, an oscillation device, a physical quantity measuring device, an electronic device, a moving body, and the like that can reduce the risk of impersonation of the oscillation device or the physical quantity measuring device.

  SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following forms or modes.

  One embodiment of the present invention is an information based on unique information of an oscillation circuit that generates an oscillation signal using an oscillator, a processing unit that controls the oscillation circuit, and a circuit device, for authenticating the circuit device And an interface unit that outputs the authentication information to an external device.

  According to one aspect of the present invention, authentication information for authenticating a circuit device, which is information based on unique information of the circuit device, is output from the circuit device to an external device via the interface unit. As a result, the external device can authenticate the circuit device based on the received authentication information, and the risk of impersonation of the circuit device (oscillation device, physical quantity measuring device) can be reduced.

  In one embodiment of the present invention, the circuit device includes a non-volatile memory that stores the oscillation adjustment data and the unique information of the oscillation circuit, or stores the oscillation adjustment data as the unique information, and the interface unit includes: The authentication information based on the unique information stored in the nonvolatile memory may be output to the external device.

  According to one aspect of the present invention, the unique information can be stored by using the free area of the nonvolatile memory for storing the oscillation adjustment data of the oscillation circuit. Alternatively, the oscillation adjustment data stored in the nonvolatile memory can be used as unique information.

  In the aspect of the invention, the circuit device may include an encryption processing unit, and the interface unit may output the authentication information encrypted by the encryption processing unit to the external device.

  In this way, the possibility that the security is broken can be reduced and the security of the system can be improved as compared with the case where the circuit device transmits the authentication information as non-encrypted data to the external device.

  In the aspect of the invention, the interface unit receives external device authentication information for authenticating the external device, and the processing unit performs authentication processing of the external device based on the external device authentication information. May be.

  In this way, mutual authentication can be performed between the external device and the circuit device. That is, security can be improved not only for impersonation of a circuit device (oscillation device, physical quantity measuring device) but also for impersonation of an external device as a counterpart with which the circuit device communicates.

  In one embodiment of the present invention, the circuit device may include an encryption processing unit that decrypts the encrypted external device authentication information.

  In this way, it is possible to improve security compared to the case where the circuit device receives external device authentication information as non-encrypted data from the external device. Further, the external device authentication information can be decrypted by sharing an encryption processing unit that encrypts the authentication information transmitted from the circuit device to the external device.

  In one aspect of the present invention, the circuit device includes a random number data output unit that outputs random number data, and the interface unit outputs the authentication information generated by a combination of the unique information and the random number data to the external device. May be output.

  In this way, compared to the case where the circuit device transmits the authentication information generated without combining the random number data to the external device, the authentication information becomes complicated, so that the possibility of security breakage can be reduced. Security can be improved.

  In one aspect of the present invention, the authentication information is data in which a bit of the specific information is assigned to a given bit of the authentication information and a bit of the random number data is assigned to another bit of the authentication information. There may be.

  Thus, by assigning a bit of unique information to a given bit of authentication information and assigning a bit of random number data to another bit of authentication information, authentication information can be generated by combining the unique information and random number data. it can. The external device can acquire the specific information by extracting a given bit to which the bit of the specific information is assigned from the authentication information.

  In the aspect of the invention, the interface unit may output the authentication information generated by a combination of the unique information and circuit characteristic adjustment data.

  Since circuit characteristics have individual variations, circuit characteristics adjustment data for adjusting the circuit characteristics also have individual variations. Therefore, the circuit characteristic adjustment data can be used as random number data.

  In one aspect of the present invention, the authentication information includes a bit of the unique information assigned to a given bit of the authentication information, and a bit of the circuit characteristic adjustment data assigned to another bit of the authentication information. It may be data.

  In this way, by assigning a bit of unique information to a given bit of authentication information and assigning a bit of circuit characteristic adjustment data to another bit of authentication information, the authentication information is combined with the unique information and circuit characteristic adjustment data. Can be generated. The external device can acquire the specific information by extracting a given bit to which the bit of the specific information is assigned from the authentication information.

  In the aspect of the invention, the unique information may be PUF (Physically Unclonable Function) information unique to the circuit device.

  Since PUF information uses individual variations in hardware characteristics, it is very unlikely that a circuit device having the same PUF information can be duplicated. By using such PUF information as unique information, it is possible to reduce the possibility of impersonation of a circuit device (oscillation device, physical quantity measuring device) due to duplication or the like and improve security.

  In the aspect of the invention, the PUF information may be information generated based on temperature compensation data of an oscillation frequency of the oscillation signal.

  According to one aspect of the present invention, unique PUF information for a circuit device is generated based on temperature compensation data. An oscillation device that performs temperature compensation stores temperature compensation data, and the temperature compensation data has individual variations. Therefore, it is possible to generate PUF information specific to the circuit device from the temperature compensation data.

  In one aspect of the present invention, the circuit device includes a timing unit that generates timing data that is real-time clock information based on the oscillation signal, and the interface unit outputs the timing data to the external device, The authentication information may be information for authenticating the circuit device that outputs the timing data.

  By impersonating a real-time clock device that outputs time measurement data, for example, the system time may be set to an incorrect time. In this regard, according to one aspect of the present invention, authentication information for the external device to authenticate the circuit device can be output from the circuit device to the external device, so that the possibility of impersonation of the real-time clock device can be reduced. Thereby, the security of the system including the real-time clock device can be improved.

  In one embodiment of the present invention, the circuit device includes a time digital conversion circuit that performs time digital conversion based on the oscillation signal, and the interface unit transmits information generated based on the time digital conversion to the external device. May be output.

  Such a time digital converter is one of devices that may communicate with an external device, and there is a risk of impersonation. In this regard, according to one aspect of the present invention, the circuit device outputs authentication information to the external device, so that the external device can authenticate the time digital converter, and the possibility of impersonation of the time digital converter can be reduced.

  Another aspect of the invention relates to an oscillation device including the circuit device according to any one of the above and the oscillator.

  Still another embodiment of the present invention relates to a physical quantity measuring device including any one of the circuit devices described above and the oscillator.

  Still another embodiment of the present invention relates to an electronic apparatus including any one of the circuit devices described above and the external device.

  Still another embodiment of the present invention relates to a moving body including any one of the circuit devices described above and the external device.

1 is a configuration example of a circuit device according to the present embodiment. 1 is a first detailed configuration example of a circuit device according to an embodiment and a system including the circuit device. The 2nd detailed structural example of the system containing the circuit device and circuit device of this embodiment. The circuit apparatus of this embodiment, and the 3rd detailed structural example of the system containing a circuit apparatus. 4 is a fourth detailed configuration example of a circuit device according to the present embodiment and a system including the circuit device. The 2nd structural example of the circuit apparatus of this embodiment, and the detailed structural example of an oscillation circuit. An example of temperature compensation data stored in a non-volatile memory. The characteristic example of the capacitance value of the adjustment circuit with respect to temperature. An example of address selection when generating unique information. 3 is a detailed configuration example of a circuit device according to the present embodiment. Configuration example of an oscillation device. The structural example of a physical quantity measuring apparatus. Configuration example of an electronic device. Configuration example of a moving body.

  Hereinafter, preferred embodiments of the present invention will be described in detail. The present embodiment described below does not unduly limit the contents of the present invention described in the claims, and all the configurations described in the present embodiment are indispensable as means for solving the present invention. Not necessarily.

  In the following description, the case where the oscillation device is a real-time clock device will be described as an example. However, the present invention is not limited to this, and the present invention is not limited to this, and various oscillation devices (for example, an oscillator such as a temperature compensated crystal oscillator (TCXO)) The present invention can also be applied to a physical quantity measuring device using a child (for example, a time digital converter).

1. Circuit Device As described above, a conventional real-time clock device (oscillation device) takes security measures against impersonation on the external device side. For this reason, when the real-time clock device is viewed from an external device, no security measures have been taken against impersonation of the real-time clock device.

  For example, consider a system including a CPU that is an external device and a real-time clock device that transmits timing data to the CPU. In such a system, for example, it is assumed that the real-time clock device mounted on the board is replaced with an unauthorized device, or impersonation is performed as if the communication is from the real-time clock device to communicate with the CPU. When such an illegal act is performed, for example, illegal timing data is transmitted to the CPU, and hacking is performed such as causing the CPU to perform erroneous authentication using a past (which should already be invalid) electronic signature. there is a possibility.

  For example, in a mobile body such as an automobile, an internal network and an external network (or external device) of the mobile body communicate with each other via various communications such as mobile communication, Bluetooth (registered trademark) communication, and wired communication. The internal network may be hacked through such communication, and the real-time clock device may be spoofed as described above.

  FIG. 1 is a configuration example of a circuit device according to the present embodiment that can solve the above-described problems and a system that includes the circuit device. The system in FIG. 1 includes an external device 200 and a circuit device 100. The external device 200 includes a processing unit 210 and an interface unit 220. The circuit device 100 includes an oscillation circuit 80, a processing unit 10 (processing circuit), and an interface unit 60 (interface circuit). Further, the circuit device 100 can include a nonvolatile memory 40. The circuit device 100 can include a timer unit 30. The circuit device is not limited to the configuration shown in FIG. 1, and various modifications such as omitting some of these components or adding other components are possible.

  The external device 200 is, for example, an SOC (System On Chip). Alternatively, a processing device such as a CPU or MPU may be used. The circuit device 100 can be realized by an integrated circuit device, for example. For example, a real-time clock device is configured by combining the circuit device 100 of FIG. 1 and the oscillator XTAL. Note that the present embodiment is not limited to the configuration shown in FIG. 1, and various modifications such as omitting some of the components or adding other components are possible.

  The oscillation circuit 80 generates an oscillation signal using the oscillator XTAL. The processing unit 10 controls the oscillation circuit 80. The interface unit 60 is information based on the unique information of the circuit device 100 and outputs authentication information for authenticating the circuit device 100 to the external device 200.

  The unique information of the circuit device 100 is information uniquely corresponding to each circuit device. That is, it is information that can identify the individual circuit device or the legitimacy of the circuit device (for example, whether it is an assumed product) by the unique information. As will be described later, the unique information may be, for example, PUF information using a characteristic variation of hardware, or may be identification information given arbitrarily. The unique information may be information that does not overlap at all, or may be allowed to overlap within a range in which security can be maintained.

  The authentication information is information for determining whether or not to permit communication by authenticating a circuit device to be communicated. That is, it is information for determining whether or not a circuit device to be communicated is valid (for example, whether or not it is an assumed product). The authentication information may be the unique information itself, or may be information generated by performing some processing on the unique information. For example, the authentication information data is data obtained by extracting some data (bits) from the unique information data, data obtained by adding random data (for example, random number data) to the unique information, or the data or the unique information itself. It may be data that has been processed.

  The external device 200 receives the authentication information output (transmitted) from the interface unit 60 of the circuit device 100 via the interface unit 220. Then, the processing unit 210 performs an authentication process based on the received authentication information, and determines whether to authenticate the circuit device 100 (whether communication with the circuit device 100 is permitted). For example, authentication processing is performed by comparing the received authentication information with an expected value. If the authentication fails, communication with the circuit device 100 thereafter is not permitted. If the authentication is successful, normal communication processing such as initial setting of the circuit device 100 and data communication with the circuit device 100 is performed. Allow.

  According to the present embodiment, authentication information for the external device 200 to authenticate the circuit device 100 can be output from the circuit device 100 to the external device 200. Thereby, the possibility of impersonation of the circuit device 100 (real-time clock device including the circuit device 100) can be reduced. That is, the external device 200 can determine from the authentication information whether the circuit device 100 that has transmitted the authentication information (that is, connected to the external device 200) is a device to communicate with. Thereby, for example, when there is an unauthorized act such as replacing the real-time clock device mounted on the substrate with an unauthorized device, this can be detected, and security can be improved.

  In the present embodiment, the timer unit 30 generates time data that is real-time clock information based on the oscillation signal. The interface unit 60 outputs time data to the external device 200, and the authentication information is information for authenticating the circuit device 100 that outputs the time data.

  The external device 200 receives time measurement data via the interface unit 220, and the processing unit 210 performs processing based on the received time measurement data. For example, the processing unit 210 reads time-measurement data from the circuit device 100 (real-time clock device) when the main power of the system is turned on, and initializes the system time.

  The time measurement data is data representing time as real-time clock information. That is, the time data measured by the timer unit 30 as the real-time clock information. For example, the time measurement data is data indicating date and time, and can include calendar data and time data. For example, the calendar data is data such as year, month, week, and day, and the time data is data such as hour, minute, and second. For example, the timer unit 30 divides the oscillation signal to generate a clock signal with a period of 1 second, and measures the time by counting the clock signal.

  The real-time clock device is a device that operates with a backup power source such as a battery and keeps timing (measurement of real time) even when the main power supply of the system is turned off. When the main power is turned on, the external device 200 refers to the time measurement data of the real time clock device and initializes the system time. For example, when the external device 200 performs data authentication using an electronic signature, the external device 200 compares the issuance time of an electronic signature attached to data transmitted via a network or the like with the system time, and verifies the electronic signature. I do. At this time, the system time needs to be set to the correct time, but the system time may be set to an incorrect time due to impersonation of the real-time clock device, and the electronic signature may not be correctly verified.

  In this regard, according to the present embodiment, since the external device 200 can output authentication information for authenticating the real-time clock device (circuit device 100) from the circuit device 100 to the external device 200, there is a risk of impersonation of the real-time clock device. Can be reduced. Thereby, the security of the system including the real-time clock device can be improved.

  In the present embodiment, the nonvolatile memory 40 stores the oscillation adjustment data of the oscillation circuit 80. Specifically, the nonvolatile memory 40 stores oscillation adjustment data and unique information, or stores the oscillation adjustment data as unique information. Then, the interface unit 60 outputs authentication information based on the unique information stored in the nonvolatile memory 40 to the external device 200.

  The oscillation adjustment data is data for adjusting (setting) the oscillation characteristics of the oscillator XTAL and the oscillation circuit 80. For example, it is data for adjusting the oscillation frequency at a reference temperature (for example, 25 degrees Celsius) to a predetermined frequency (a frequency defined by the specification). Alternatively, when the circuit device 100 performs temperature compensation of the oscillation frequency, the oscillation adjustment data is temperature compensation data. The oscillation adjustment data is, for example, trimming data of an analog circuit (for example, a resistor divider circuit or an amplifier circuit that outputs a reference voltage) or control data that controls a switch of the capacitor array. Alternatively, the oscillation adjustment data is data for generating the above trimming data and control data by processing the oscillation adjustment data. For example, in temperature compensation, when control data corresponding to each temperature is stored in the nonvolatile memory 40, the control data is oscillation adjustment data. Alternatively, when the VCO control voltage is generated by an approximate polynomial having temperature as a variable, the coefficient data of the approximate polynomial is the oscillation adjustment data.

  The nonvolatile memory 40 stores unique information separately from the oscillation adjustment data, for example. In this case, the unique information is data uniquely attached to the circuit device 100 such as identification data (ID), for example, and is written in the nonvolatile memory 40 when the circuit device 100 or the real-time clock device is manufactured. Alternatively, the oscillation adjustment data stored in the nonvolatile memory 40 may be used as unique information. In this case, the oscillation adjustment data is PUF information.

  In order to store the oscillation adjustment data of the oscillation circuit 80, a nonvolatile memory 40 may be provided. In the present embodiment, the unique information can be stored using such an empty area of the nonvolatile memory 40. Alternatively, the oscillation adjustment data stored in the nonvolatile memory 40 can be used as unique information. That is, since the oscillation characteristics of the oscillation circuit 80 have individual variations, the oscillation adjustment data for adjusting the oscillation characteristics also has individual variations, and the oscillation adjustment data can be used as unique information of the circuit device 100.

  In addition, although the case where the non-volatile memory 40 stores unique information has been described above, the present embodiment is not limited to this. That is, a component other than the nonvolatile memory 40 may output, store, or generate unique information. For example, the circuit device 100 may include an SRAM, and initial data (PUF information) of the SRAM when the circuit device 100 is activated may be used as the unique information. Alternatively, the circuit device 100 may include a PUF circuit that generates PUF information using individual variation in delay time of the delay elements, and the PUF information output by the PUF circuit may be used as unique information.

  In the present embodiment, the circuit device 100 may include a cryptographic processing unit (for example, the cryptographic processing unit 14 in FIGS. 4 and 5, a cryptographic processing circuit). The interface unit 60 may output the authentication information encrypted by the encryption processing unit to the external device 200.

  As encryption processing (encryption and decryption), for example, a common key cryptosystem such as AES (Advanced Encryption Standard) or a public key cryptosystem such as RSA can be used. For example, the cryptographic processing unit may be included in the processing unit 10 as shown in FIG. 4 or the like, or may be provided as a separate circuit from the processing unit 10.

  In this way, the security can be improved (the possibility that the security is broken can be reduced) as compared with the case where the circuit device 100 transmits the authentication information as non-encrypted data (for example, plain text data) to the external device 200.

  In the present embodiment, the interface unit 60 may receive external device authentication information for authenticating the external device 200. Then, the processing unit 10 may perform an authentication process for the external device 200 based on the external device authentication information.

  Specifically, the processing unit 210 of the external device 200 transmits external device authentication information via the interface unit 220, and the interface unit 60 of the circuit device 100 receives the external device authentication information. The external device authentication information may be PUF information or identification information, for example, similarly to the authentication information output by the circuit device 100, or may be random data (for example, random number data). The processing unit 10 of the circuit device 100 performs an authentication process based on the received external device authentication information, and determines whether to authenticate the external device 200 (whether to allow communication with the external device 200). . For example, authentication processing is performed by comparing the received external device authentication information with an expected value. If the authentication fails, communication with the external device 200 thereafter is not permitted. If the authentication is successful, normal communication processing such as data communication with the external device 200 is permitted.

  In this way, mutual authentication can be performed between the external device 200 and the circuit device 100 (real-time clock device). That is, security can be improved not only for impersonation of the real-time clock device but also for impersonation of the external device 200.

  In the present embodiment, the encryption processing unit may decrypt the encrypted external device authentication information.

  Specifically, the processing unit 210 of the external device 200 encrypts the external device authentication information, and the encryption processing unit of the circuit device 100 decrypts the encrypted external device authentication information.

  In this way, security can be improved compared to the case where the circuit device 100 receives the external device authentication information from the external device 200 as unencrypted data (for example, plain text data). In addition, the external device authentication information can be decrypted by sharing an encryption processing unit that encrypts the authentication information transmitted from the circuit device 100 to the external device 200.

  In the present embodiment, the circuit device 100 may include a random number data output unit (for example, the random number data output unit 13 in FIGS. 3 to 5, a random number data output circuit) that outputs random number data. Then, the interface unit 60 outputs the authentication information generated by the combination of the unique information and the random number data to the external device 200.

  Specifically, the random number data output unit 13 outputs, as random number data, data whose values change randomly in time series or data having a random value for each individual circuit device. The processing unit 10 generates authentication information by combining the unique information and the random number data, and outputs the authentication information to the external device 200 via the interface unit 60. For example, the random number data output unit may be included in the processing unit 10 as shown in FIG. 3 or the like, or may be provided as a circuit different from the processing unit 10. The combination information of unique information and random number data (information indicating how to combine them) is shared in advance between the circuit device 100 and the external device 200. Then, the processing unit 210 of the external device 200 extracts specific information from the received authentication information based on the combination information, and performs authentication processing based on the specific information.

  In this way, the authentication information is more complex than when the circuit device 100 transmits the authentication information generated without combining the random number data to the external device 200, so that security can be improved (security can be broken). Can be reduced).

  In this embodiment, the authentication information is data in which a bit of unique information is assigned to a given bit of the authentication information and a bit of random number data is assigned to the other bits of the authentication information.

  In this way, authentication information can be generated by combining unique information and random number data by interweaving bits of unique information and bits of random number data. The external device 200 can acquire the specific information by extracting a given bit to which the bit of the specific information is assigned from the authentication information.

  Note that the combination method of the unique information and the random number data is not limited to this, and various methods can be used. For example, authentication information may be generated by performing some arithmetic processing (for example, addition or multiplication) using the unique information and random number data.

  In the present embodiment, the interface unit 60 may output authentication information generated by a combination of unique information and circuit characteristic adjustment data.

  The circuit characteristic adjustment data is data for adjusting (setting) the characteristics of each part of the circuit device 100. For example, it is data for adjusting a reference voltage supplied to each part of the circuit device 100. Alternatively, the above-described oscillation adjustment data may be used as circuit characteristic adjustment data. The circuit characteristic adjustment data is, for example, trimming data of an analog circuit (for example, a resistor divider circuit or an amplifier circuit that outputs a reference voltage), and is stored in the nonvolatile memory 40, for example.

  Since circuit characteristics have individual variations, circuit characteristics adjustment data for adjusting the circuit characteristics also have individual variations. Therefore, the circuit characteristic adjustment data can be used as random number data. The circuit characteristic adjustment data corresponds to random number data having a random value for each individual circuit device.

  In this embodiment, the authentication information is data in which a bit of unique information is assigned to a given bit of authentication information and a bit of circuit characteristic adjustment data is assigned to other bits of the authentication information.

  In this way, by combining the bits of the unique information and the bits of the circuit characteristic adjustment data, the authentication information can be generated by combining the unique information and the circuit characteristic adjustment data. The external device 200 can acquire the specific information by extracting a given bit to which the bit of the specific information is assigned from the authentication information.

  Note that the combination method of the unique information and the circuit characteristic adjustment data is not limited to this, and various methods can be used. For example, authentication information may be generated by performing some arithmetic processing (for example, addition or multiplication) using the unique information and the circuit characteristic adjustment data.

  In the present embodiment, the unique information may be unique PUF information of the circuit device 100.

  The PUF information is data (PUF code) unique to the circuit device, which is obtained by using individual variations in hardware characteristics. As described above, examples of PUF information are oscillation adjustment data stored in the non-volatile memory 40, SRAM initial data when power is turned on, and output data of the PUF circuit using individual variations in delay time of delay elements. is there.

  Since PUF information uses individual variations in hardware characteristics, it is very unlikely that a circuit device having the same PUF information can be duplicated. By using such PUF information as unique information, it is possible to reduce the possibility of impersonation of the real-time clock device by copying or the like and improve security.

  In the present embodiment, the PUF information may be information generated based on temperature compensation data of the oscillation frequency of the oscillation signal.

  Specifically, the nonvolatile memory 40 (storage unit) stores temperature compensation data of the oscillation frequency of the oscillation signal. Then, the processing unit 10 generates unique PUF information of the circuit device 100 based on the temperature compensation data.

  The temperature compensation is to cancel (suppress) the temperature characteristic (temperature dependency) of the oscillation frequency of the oscillation signal and to keep the oscillation frequency constant (substantially constant). The temperature compensation data is data used for the temperature compensation. For example, the temperature compensation data is control data for controlling a switch of a capacitor array provided in the oscillation circuit. Alternatively, the temperature compensation data is data for generating control data by processing the temperature compensation data. For example, control data corresponding to each temperature is stored in the nonvolatile memory 40, and the capacitor array is controlled by the control data corresponding to the measured temperature. This control data is temperature compensation data. Alternatively, when the VCO control voltage is generated by an approximate polynomial having temperature as a variable, the coefficient data of the approximate polynomial is the temperature compensation data. The temperature compensation data is not limited to being stored in the nonvolatile memory 40, and the temperature compensation data may be stored in a RAM such as an SRAM, a register, a fuse, or the like.

  According to the present embodiment, since the PUF information uses individual variations in hardware characteristics, the possibility that a circuit device having the same PUF information can be duplicated is very low. By using such PUF information, it is possible to reduce the risk of impersonation of the real-time clock device by duplication or the like and the possibility of impersonation of an external device, thereby improving security. An oscillation device that performs temperature compensation stores temperature compensation data, and the temperature compensation data has individual variations. Therefore, it is possible to generate PUF information specific to the circuit device from the temperature compensation data.

  Although the case where the method of the present invention is applied to a real-time clock device has been described above as an example, the method of the present invention may be applied to a physical quantity measuring device. FIG. 12 shows a time digital converter as an example of the physical quantity measuring device. Here, an outline will be described, and details will be described later.

  In the embodiment shown in FIG. 12, the circuit device 750 includes a time digital conversion circuit 740 that performs time digital conversion based on the oscillation signal. Then, the interface unit 60 outputs information (for example, a digital value DQ of time) generated based on the time digital conversion to the external device 200.

  The time digital converter is used in, for example, a distance-of-flight (TOF) distance measuring sensor, and the distance measuring sensor is used, for example, for an in-vehicle device to detect a distance to an object around a car. For example, such a distance measuring technique is used to realize driver assistance and automatic driving.

  Such a time digital converter (physical quantity measuring device) is one of devices that communicate with an external device (for example, SOC) in the same manner as a real-time clock device. That is, there is a risk of impersonation similar to a real-time clock device. According to this embodiment, since the circuit device 750 (interface unit 60) outputs authentication information to the external device 200, the external device 200 can authenticate the time digital converter, and the possibility of impersonation of the time digital converter can be reduced. . Thus, for example, the in-vehicle device can perform distance measurement based on the output of a valid time digital converter.

2. Detailed Configuration Example of Circuit Device and System FIG. 2 is a first detailed configuration example of a system including the circuit device 100 and the circuit device 100 of the present embodiment. FIG. 2 schematically shows the configuration and operation (processing). Further, the oscillation circuit 80, the time measuring unit 30, and the processing unit 10 are not shown.

  In the first detailed configuration example, the interface unit 60 of the circuit device 100 transmits the PUF information DA1 to the interface unit 220 of the external device 200 as authentication information. The PUF information is, for example, data stored in the nonvolatile memory 40, but is not limited thereto, and may be SRAM initial data or data output from the PUF circuit. Moreover, since unique information should just be output, identification information (ID) may be output instead of PUF information.

  The interface unit 60 of the circuit device 100 transmits the public key DA2 stored in the nonvolatile memory 40 to the interface unit 220 of the external device 200. The public key DA2 is written in the nonvolatile memory 40, for example, when the system is manufactured (when an electronic device or the like incorporating an oscillation device or a physical quantity measuring device is manufactured).

  The processing unit 210 of the external device 200 performs arithmetic processing SA1 (for example, decryption processing) based on the received PUF information DA1 and public key DA2, and generates a PUF code DA3. For example, the public key DA2 is key data generated in advance so that the expected value DA4 stored in the external device 200 can be decrypted from the PUF information DA1 unique to the circuit device 100. A PUF code DA3 is generated by performing decryption processing (arithmetic processing SA1) on the PUF information DA1 using the public key DA2.

  The processing unit 210 performs a process SA2 for comparing the generated PUF code DA3 and the expected value DA4, and performs an authentication process based on the comparison result. That is, when the PUF code DA3 and the expected value DA4 match, it is determined that the authentication is established, and when the PUF code DA3 and the expected value DA4 do not match, it is determined that the authentication is not established.

  FIG. 3 is a second detailed configuration example of the circuit device 100 and the system including the circuit device 100 according to the present embodiment. Note that FIG. 3 schematically illustrates the configuration and operation (processing). Further, the oscillation circuit 80 and the timer unit 30 are not shown. Also, description of operations similar to those of the first detailed configuration example will be omitted as appropriate.

  In the second detailed configuration example, the processing unit 10 of the circuit device 100 combines the PUF information DB2 stored in the nonvolatile memory 40 and the random number data DB1 output from the random number data output unit 13 to obtain authentication information. A process SB1 to be generated is performed. The interface unit 60 transmits the authentication information to the interface unit 220 of the external device 200. The interface unit 60 of the circuit device 100 transmits the public key DB 3 stored in the nonvolatile memory 40 to the interface unit 220 of the external device 200.

  The processing unit 210 of the external device 200 extracts the PUF information DB 2 from the received authentication information. The processing unit 210 performs arithmetic processing SB2 (for example, decryption processing) based on the extracted PUF information DB2 and the received public key DB3, and generates a PUF code DB4. The processing unit 210 performs a process SB3 for comparing the generated PUF code DB4 and the expected value DB5, and performs an authentication process based on the comparison result.

  FIG. 4 is a third detailed configuration example of the circuit device 100 according to the present embodiment and a system including the circuit device 100. FIG. 4 schematically shows the configuration and operation (processing). Further, the oscillation circuit 80 and the timer unit 30 are not shown. Also, description of operations similar to those in the first and second detailed configuration examples will be omitted as appropriate.

  In the third detailed configuration example, the processing unit 10 of the circuit device 100 performs a process SC1 that combines the PUF information DC2 stored in the nonvolatile memory 40 and the random number data DC1 output from the random number data output unit 13. . Then, the encryption processing unit 14 encrypts the output data of the process SC1, and the interface unit 60 transmits the encrypted data to the interface unit 220 of the external device 200 as authentication information. For example, the encryption processing unit 14 performs encryption by the AES method using a common key common to the external device 200. Further, the interface unit 60 of the circuit device 100 transmits the public key DC3 stored in the nonvolatile memory 40 to the interface unit 220 of the external device 200.

  The encryption processing unit 214 of the external device 200 decrypts the PUF information DC2 from the received authentication information. For example, the encryption processing unit 214 performs decryption by the AES method using a common key common to the circuit device 100. The processing unit 210 performs arithmetic processing SC2 (for example, decryption processing) based on the decrypted PUF information DC2 and the received public key DC3, and generates a PUF code DC4. The processing unit 210 performs a process SC3 for comparing the generated PUF code DC4 with the expected value DC5, and performs an authentication process based on the comparison result.

  FIG. 5 is a fourth detailed configuration example of the circuit device 100 according to the present embodiment and a system including the circuit device 100. FIG. 5 schematically shows the configuration and operation (processing). Further, the oscillation circuit 80 and the timer unit 30 are not shown. Also, description of operations similar to those in the first to third detailed configuration examples will be omitted as appropriate.

  In the fourth detailed configuration example, the first authentication process in which the external device 200 authenticates the circuit device 100 and the second authentication process in which the circuit device 100 authenticates the external device 200 are performed.

  In the first authentication process, the processing unit 10 of the circuit device 100 performs the process SD1 that combines the PUF information DD2 and the random number data DD1, the encryption processing unit 14 encrypts the output data of the process SD1, and the interface unit 60 The encrypted data is transmitted to the interface unit 220 of the external device 200 as authentication information. The encryption processing unit 214 of the external device 200 decrypts the PUF information DD2 from the received authentication information, performs a process SD3 that compares the decrypted PUF information DD2 and the expected value DD5, and performs an authentication process based on the comparison result. .

  In the second authentication process, the random number data output unit 213 of the external device 200 outputs the random number data DD4, and the encryption processing unit 214 encrypts the random number data DD4. The interface unit 220 transmits the encrypted data of the random number data DD4 (external device authentication information) and the plaintext random number data DD4 to the interface unit 60 of the circuit device 100. The cryptographic processing unit 14 of the circuit device 100 decrypts the received encrypted data to generate random number data DD3. The processing unit 10 performs a process SD2 for comparing the decrypted random number data DD3 and the received plaintext random number data DD4 (expected value), and performs an authentication process based on the comparison result.

3. Authentication Information Generation Method A detailed example of a method for generating authentication information from unique information when using temperature compensation data as unique information will be described.

  FIG. 6 shows a second configuration example of the circuit device 100 of this embodiment and a detailed configuration example of the oscillation circuit. The circuit device 100 includes a temperature sensor 5, a nonvolatile memory 40, a processing unit 10, and an oscillation circuit 80. In FIG. 6, the timing unit 30 is omitted.

  The oscillation circuit 80 includes an amplifier circuit 81 that drives (oscillates) the oscillator XTAL to generate the oscillation signal OSC, and a variable capacitance circuit 82 that adjusts the oscillation frequency of the oscillation signal. The amplifier circuit 81 has a first node connected to one end of the oscillator XTAL, and a second node connected to the other end of the oscillator XTAL. The variable capacitance circuit 82 is provided at the first node (or the second node) of the amplifier circuit 81 and is configured by a capacitor array. Specifically, the variable capacitance circuit 82 includes switch elements SW1 to SWm having one end connected to the first node and capacitors C1 to Cm having one end connected to the other end of the switch elements SW1 to SWm. . m is an integer of 2 or more. The other ends of the capacitors C1 to Cm are connected to a node of a reference voltage (for example, a low potential side power supply voltage). The capacitance values of the capacitors C1 to Cm are weighted by, for example, binary (power of 2). The switch elements SW1 to SWm are composed of transistors, for example.

  The temperature sensor 5 is a sensor that detects the temperature of the circuit device 100 (environmental temperature; the temperature of the substrate of the circuit device 100). Specifically, the temperature sensor 5 includes a sensor circuit that outputs a temperature detection signal and an A / D conversion circuit that A / D converts the temperature detection signal and outputs temperature detection data. The sensor circuit is a circuit that generates a temperature detection signal based on, for example, the temperature dependence of the forward voltage of the PN junction.

  The nonvolatile memory 40 stores temperature compensation data corresponding to each temperature in the temperature range where temperature compensation is performed. Then, the nonvolatile memory 40 outputs temperature compensation data for the temperature corresponding to the temperature detection data.

  FIG. 7 is an example of temperature compensation data stored in the nonvolatile memory 40. Temperature compensation data DATA0 to DATA127 are stored in the storage area of addresses 0 to 127 of the nonvolatile memory 40. One address corresponds to one temperature in the temperature range. For example, addresses 0 to 127 correspond to 128 temperatures obtained by dividing the temperature range into 128 equal parts. Each data of the temperature compensation data DATA0 to DATA127 is data composed of the first to mth bits D1 to Dm.

  The processing unit 10 decodes the temperature detection data into the address of the nonvolatile memory 40 and reads the temperature compensation data at the address from the nonvolatile memory 40. The processing unit 10 outputs control signals corresponding to the bits D1, D2,..., Dm of the temperature compensation data to the switch elements SW1, SW2,. For example, when the bit Di = 1, the switch element SWi is turned on, and when the bit Di = 0, the switch element SWi is turned off. i is an integer of 1 to m.

  As described above, the temperature compensation data corresponding to the detected temperature is selected from the temperature compensation data DATA0 to DATA127, and the connection and non-connection of the capacitors C1 to Cm are selected based on the temperature compensation data. The OSC oscillation frequency is temperature compensated. The temperature compensation data DATA0 to DATA127 are data measured at the time of manufacturing the oscillation device and the physical quantity measurement device so that the oscillation frequency of the oscillation signal OSC is constant (including substantially constant) regardless of the temperature.

  FIG. 8 is a characteristic example of the capacitance value of the variable capacitance circuit 82 with respect to temperature. In FIG. 8, the horizontal axis represents an address corresponding to the temperature.

  The temperature characteristic of the oscillation frequency of the resonator XTAL has a characteristic of a quadratic function (substantially quadratic function) with respect to the temperature. Correspondingly, the characteristic of the capacitance value is also a quadratic function (substantially quadratic function). It has become a characteristic. FIG. 8 illustrates capacitance value characteristics TS1 to TS5 of five samples (oscillation devices) as an example. As can be seen from these characteristics TS1 to TS5, it can be seen that the characteristics of the capacitance values are different for each sample. For example, the maximum value of the quadratic function, the address at which the quadratic function takes the maximum value, and the respective coefficient of the quadratic function (for example, the quadratic coefficient is related to the degree of opening of the parabola) are different.

  In the present embodiment, among the temperature compensation data DATA0 to DATA127 of the addresses 0 to 127, the temperature compensation data of a part (one or a plurality) of addresses is read from the nonvolatile memory 40, and the temperature compensation data of the plurality of addresses is unique. Generate information. For example, when the temperature compensation data at one address is 10-bit (m = 10) data and 100-bit unique information is generated, the temperature compensation data is read from 10 addresses and the 10 temperature compensation data are read out. Combine the data into unique information. For example, 10 bits × 10 pieces of temperature compensation data are arranged in order from the LSB side of the specific information to obtain 100-bit data.

  FIG. 9 is an example of address selection when generating unique information. Examples 1 to 6 show address areas where variations in capacitance values (difference in capacitance values) tend to occur when various parameters are changed. In this embodiment, temperature compensation data is selected from an address region where such a difference is likely to occur, and unique information is generated. In the following, an example in which address 0 corresponds to the lowest temperature in the temperature range and address 127 corresponds to the highest temperature in the temperature range will be described as an example.

  As shown in Example 1, when the second-order coefficient of the temperature characteristics of the oscillation frequency of the resonator is changed as a parameter and the other parameters are fixed (assumed), the temperature of the low temperature side address and the high temperature side address It is assumed that the dispersion of compensation data will increase.

  The low temperature side address is an address corresponding to the temperature on the low temperature side among the addresses 0 to 127. Specifically, it is address 0 or a plurality of addresses near address 0 (for example, 2 to 5 addresses). The high temperature side address is an address corresponding to the temperature on the high temperature side among the addresses 0 to 127. Specifically, the address 127 or a plurality of addresses near the address 127 (for example, 2 to 5 addresses).

  As shown in Example 2, when the apex temperature (temperature at which the maximum value is taken) of the temperature characteristics of the oscillation frequency of the resonator is changed as a parameter and other parameters are fixed (assumed), the low temperature side address and It is assumed that the variation of the temperature compensation data of the high temperature side address becomes large.

  As shown in Example 3, when the oscillation frequency of the resonator at 25 degrees Celsius (so-called room temperature) is changed as a parameter and the other parameters are fixed (assumed), variation in temperature compensation data at the intermediate temperature address Is expected to increase.

  The medium temperature address is an address between the low temperature side address and the high temperature side address among the addresses 0 to 127. Specifically, the address 63 or a plurality of addresses near the address 63 (for example, 2 to 5 addresses).

  As shown in Example 4, when the capacitance value of the adjustment circuit that adjusts the oscillation frequency of the resonator is changed as a parameter and other parameters are fixed (assumed), the low temperature side address and the high temperature It is assumed that the variation of the temperature compensation data of the side address becomes large. The slow / fast characteristic is a characteristic of the oscillation frequency with respect to the capacitance value of the adjustment circuit, and the slope of the characteristic represents a change in the oscillation frequency (sensitivity) with respect to a change in the capacitance value.

  As shown in Example 5, when the A / D conversion accuracy of the A / D conversion circuit for A / D converting the temperature detection signal is changed as a parameter, and other parameters are fixed (assumed), the lower temperature side It is assumed that the variation of the temperature compensation data between the address and the high temperature side address becomes large.

  As shown in Example 6, when the capacitance value variation of the capacitors C1 to Cm of the adjustment circuit is changed as a parameter and other parameters are fixed (assumed), temperature compensation of the low temperature side address and the high temperature side address It is assumed that the variation in data will increase.

  From the above Examples 1 to 6, in this embodiment, the temperature compensation data of the low temperature side address, the high temperature side address, and the address (intermediate temperature address) between them is used as the unique information. For example, one of the low temperature side address, the high temperature side address, and an address between them, or preferably two or more are used. If the temperature compensation data is selected from a plurality of temperature regions, the uniqueness of the unique information can be expected to increase (the overlapping rate decreases). Also, it can be expected that the uniqueness of the unique information increases as the number of addresses to be selected increases.

4). Detailed Configuration Example of Circuit Device FIG. 10 is a detailed configuration example of the circuit device 100 of the present embodiment. The circuit device 100 includes a processing unit 10 (processing circuit), a memory 21, a nonvolatile memory 40, a timer unit 30 (timer circuit), and a temperature sensor 5. The circuit device 100 includes a power supply control unit 50 (power supply control circuit), an interface unit 60 (interface circuit), an interrupt control unit 70 (interrupt control circuit), an oscillation circuit 80, and a clock signal output control unit 90 (clock signal output circuit). , Terminals TVBAT, TVOUT, TVDD, TEVIN, TSCL, TSDA, TIRQ, TFOUT, XI, XO. In addition, the same code | symbol is attached | subjected about the component same as the component demonstrated in FIG. 1 etc., and description is abbreviate | omitted suitably. Here, the circuit device is not limited to the configuration of FIG. 10, and various modifications such as omitting some of the components or adding other components are possible.

  The backup power supply voltage VBAT supplied from the backup power supply is input to the terminal TVBAT. The main power supply voltage VDD supplied from the main power supply is input to the terminal TVDD. The power supply control unit 50 selects the main power supply voltage VDD or the backup power supply voltage VBAT, and supplies the selected voltage to each unit of the circuit device 100 as the voltage VOUT (internal power supply voltage of the circuit device 100). Specifically, when the main power supply voltage VDD exceeds a given voltage, the main power supply voltage VDD is selected, and when the main power supply voltage VDD falls below the given voltage, the backup power supply voltage VBAT is selected. To do. For example, the power supply control unit 50 includes a comparator that compares the main power supply voltage VDD with a given voltage, and an analog switch circuit that is turned on and off based on the output of the comparator.

  The processing unit 10 includes a control unit 11 that controls each unit of the circuit device 100 and an event control unit 12 that performs event control processing.

  Specifically, a signal EVIN indicating whether or not an event (external event) has occurred is input to the event control unit 12 from the outside of the circuit device 100 via the terminal TEVIN. When the signal EVIN changes from inactive to active, the event control unit 12 notifies the control unit 11 of that fact. When the control unit 11 receives the notification, the control unit 11 writes the time stamp (time data) of the event in the memory 21. The memory 21 is a RAM such as an SRAM.

  The random number data output unit 13 outputs random number data to be combined with unique information. The control unit 11 generates authentication information by combining the unique information and the random number data, and outputs the authentication information to the encryption processing unit 14. The encryption processing unit 14 encrypts the authentication information and outputs it to the interface unit 60.

  The oscillation circuit 80 is connected to one end of the oscillator XTAL via the terminal XI and is connected to the other end of the oscillator XTAL via the terminal XO, and drives the oscillator XTAL to oscillate. The oscillation circuit 80 has the configuration described in FIG. 6, for example, but is not limited to this. For example, the variable capacitance circuit 82 may be omitted when temperature compensation is not performed.

  The oscillator XTAL is a piezoelectric vibrator such as a quartz vibrator. Alternatively, the resonator XTAL may be a resonator (an electromechanical resonator or an electrical resonance circuit). As the oscillator XTAL, a piezoelectric vibrator, a SAW (Surface Acoustic Wave) resonator, a MEMS (Micro Electro Mechanical Systems) vibrator, or the like can be adopted. As a substrate material of the oscillator XTAL, a piezoelectric single crystal such as crystal, lithium tantalate, or lithium niobate, a piezoelectric material such as piezoelectric ceramics such as lead zirconate titanate, or a silicon semiconductor material can be used. As an excitation means of the oscillator XTAL, one using a piezoelectric effect may be used, or electrostatic driving using a Coulomb force may be used.

  The timer 30 divides the oscillation signal generated by the oscillation circuit 80 to generate a clock signal having a predetermined frequency (for example, 1 kHz), and further divides the clock signal generated by the frequency divider 31. A frequency divider 32 that generates a clock signal of 1 Hz and a clock data generator 33 that counts the clock signal of 1 Hz and generates clock data.

  For example, the time data generation unit 33 includes a counter that counts a 1 Hz clock signal and a conversion unit that converts the count value of the counter into time data (year, month, day, hour, minute, and second data). Including. When the circuit device 100 (real-time clock device) is first turned on, the initial value of the timing data is written via the interface unit 60, and the timing data is updated every second starting from the initial value.

  The clock signal output control unit 90 selects one of a plurality of clock signals (each clock signal has a different frequency) based on the oscillation signal, and uses the selected clock signal as the clock signal FOUT from the terminal TFOUT to the outside of the circuit device 100. Output to. In addition, the clock signal output control unit 90 can set the clock signal FOUT to inactive (non-output, stop).

  The interface unit 60 performs digital interface communication between the external device and the circuit device 100. For example, the interface unit 60 is a circuit that performs serial interface communication such as I2C method or SPI method. FIG. 10 illustrates the case where the I2C method is used, and the interface unit 60 inputs and outputs the serial data signal SDA via the terminal TSDA based on the clock signal SCL input from the terminal TSCL.

  The interrupt control unit 70 performs control to output an interrupt signal IRQ to an external device via the terminal TIRQ. For example, when the event control unit 12 detects the occurrence of an event, the interrupt control unit 70 activates the interrupt signal IRQ.

  Note that the processing unit 10, the timing unit 30, the interface unit 60, the interrupt control unit 70, and the clock signal output control unit 90 are configured by a logic circuit such as a gate array, for example.

5. Oscillation Device, Physical Quantity Measuring Device, Electronic Device, Mobile Object FIG. 11 is a configuration example of an oscillation device including the circuit device of this embodiment. The oscillation device 400 includes a circuit device 500 and an oscillator XTAL (an oscillator, a resonator element). Further, the oscillation device 400 can include a circuit device 500 and a package 410 in which the oscillator XTAL is accommodated. Note that the oscillation device is not limited to the configuration shown in FIG. 11, and various modifications such as omitting some of these components or adding other components are possible.

  The oscillation device 400 is, for example, a real-time clock device or an oscillator that does not have a real-time clock function. Examples of the oscillator include SPXO (Simple Packaged Crystal Oscillator), TCXO (Temperature Compensated Crystal Oscillator), and OCXO (Oven Controlled Crystal Oscillator). In the case of a real-time clock device, the circuit device 500 corresponds to the circuit device 100 of FIGS. 1 and 10, for example. In the case of an oscillator, the circuit device 500 includes, for example, an oscillation circuit 80, a processing unit 10, and an interface unit 60. The circuit device 500 can include, for example, a temperature sensor and an A / D conversion circuit.

  The package 410 includes a base part 412 and a lid part 414, for example. The base portion 412 is a member such as a box made of an insulating material such as ceramic, and the lid portion 414 is a member such as a flat plate joined to the base portion 412. For example, an external connection terminal (external electrode) for connecting to an external device is provided on the bottom surface of the base portion 412. The circuit device 500 and the oscillator XTAL are accommodated in an internal space (cavity) formed by the base portion 412 and the lid portion 414. Then, the circuit device 500 and the oscillator XTAL are hermetically sealed in the package 410 by sealing with the lid portion 414. The circuit device 500 and the oscillator XTAL are mounted in the package 410. The terminal of the oscillator XTAL and the terminal (pad) of the circuit device 500 (IC) are electrically connected by the internal wiring of the package 410.

  FIG. 12 is a configuration example of a physical quantity measuring device including the circuit device of the present embodiment. In the following, a case where the physical quantity measuring device is a time digital converter (TDC) will be described as an example. However, the physical quantity measuring device is not limited to this, and the physical quantity measuring device may be a device (sensor) that measures a physical quantity using an oscillator. That's fine. For example, a gyro sensor (vibration gyro) may be used.

  The physical quantity measuring device 700 in FIG. 12 includes oscillators XTAL1, XTAL2, and a circuit device 750. The circuit device 750 includes oscillation circuits 710 and 720, a synchronization circuit 730, a time digital conversion circuit 740, a processing unit 10, and an interface unit 60. Note that the physical quantity measuring device is not limited to the configuration shown in FIG. 12, and various modifications such as omitting some of these components (for example, a synchronization circuit) and adding other components are possible.

  The oscillation circuit 710 generates the first clock signal CK1 having the first clock frequency f1 by oscillating the oscillator XTAL1. The oscillation circuit 720 generates the second clock signal CK2 having the second clock frequency f2 by causing the oscillator XTAL2 to oscillate. The synchronization circuit 730 is a circuit that synchronizes the phases of the first clock signal CK1 and the second clock signal CK2 at predetermined intervals, and is, for example, a PLL circuit. The time-to-digital conversion circuit 740 transitions between the first signal STA (start signal) and the second signal STP (stop signal) with a resolution corresponding to the frequency difference between the first clock signal CK1 and the second clock signal CK2. The timing difference is converted into a digital value DQ. Note that the time digital conversion circuit 740 may output (spontaneously) the first signal STA based on the first clock signal DK1. The processing unit 10 controls each unit of the circuit device 100. Further, the processing unit 10 outputs the digital value DQ or data generated based on the digital value DQ to the external device via the interface unit 60. The processing unit 10 performs the authentication process described with reference to FIG. The circuit device 750 may include a non-volatile memory in which unique information is stored, and the processing unit 10 may output authentication information based on the unique information.

  FIG. 13 is a configuration example of an electronic device 300 including the circuit device of this embodiment. The electronic apparatus 300 includes a circuit device 500, an oscillator XTAL such as a crystal resonator, an antenna ANT, a communication unit 510 (communication device), and a processing unit 520 (processing device). An operation unit 530 (operation device), a display unit 540 (display device), and a storage unit 550 (memory) can be included. An oscillation device 400 is configured by the oscillator XTAL and the circuit device 500. The electronic apparatus 300 is not limited to the configuration shown in FIG. 13, and various modifications such as omitting some of these components or adding other components are possible. For example, the physical quantity measuring device 700 may be included instead of the oscillation device 400.

  As the electronic device 300 in FIG. 13, for example, an in-vehicle electronic device such as an ECU (Electronic Control Unit) or a meter panel, a video device such as a digital camera or a video camera, or a printing device such as a printer or a multifunction printer is assumed. it can. Or a wearable device such as a GPS built-in clock, a biological information measuring device (pulse meter, pedometer, etc.) or a head-mounted display device, or a mobile phone such as a smartphone, a mobile phone, a portable game device, a notebook PC, or a tablet PC. Various devices such as an information terminal (mobile terminal), a content providing terminal for distributing content, or a network-related device such as a base station or a router can be assumed.

  The communication unit 510 (wireless circuit) performs processing of receiving data from the outside via the antenna ANT and transmitting data to the outside. The processing unit 520 performs control processing of the electronic device 300, various digital processing of data transmitted / received via the communication unit 510, and the like. The function of the processing unit 520 can be realized by a processor such as a microcomputer. The operation unit 530 is for a user to perform an input operation, and can be realized by an operation button, a touch panel display, or the like. The display unit 540 displays various types of information and can be realized by a display such as a liquid crystal or an organic EL. When a touch panel display is used as the operation unit 530, the touch panel display also functions as the operation unit 530 and the display unit 540. The storage unit 550 stores data, and the function can be realized by a semiconductor memory such as a RAM or a ROM, an HDD (hard disk drive), or the like.

  FIG. 14 shows an example of a moving object including the circuit device of the present embodiment. The circuit device (oscillation device, physical quantity measuring device) of this embodiment can be incorporated into various moving bodies such as a car, an airplane, a motorcycle, a bicycle, or a ship. The moving body is, for example, a device / device that moves on the ground, in the sky, or on the sea, including a drive mechanism such as an engine or motor, a steering mechanism such as a steering wheel or rudder, and various electronic devices (on-vehicle devices). FIG. 14 schematically shows an automobile 600 as a specific example of the moving object. The automobile 600 includes a communication unit 610 that performs mobile communication such as portable wireless communication, a communication unit 620 that performs Bluetooth (registered trademark) communication, a communication unit 630 that performs wired communication such as USB, and gateway processing between these communication units and the internal network. It includes a gateway device 640, control units (control devices) ECU1 and ECU2 connected to the internal network. The control units ECU1 and ECU2 are, for example, a control unit that controls a system related to traveling such as engine control, a control unit that controls a system related to a body such as opening and closing of a door, and a control that performs information processing such as car audio. Unit etc. Control unit ECU1 includes a processing device SOC1 (external device) and a real-time clock device RTC1 that communicates with processing device SOC1. The real-time clock device RTC1 includes a circuit device 501. Control unit ECU2 includes a processing device SOC2 (external device) and a real-time clock device RTC2 that communicates with processing device SOC2. The real-time clock device RTC2 includes a circuit device 502. The circuit devices 501 and 502 correspond to the circuit device 100 of FIGS. 1 and 10, for example. The control units ECU1 and ECU2 may include an oscillation device other than the real-time clock device, or may include a physical quantity measuring device (circuit device 750 in FIG. 12).

  Although the present embodiment has been described in detail as described above, it will be easily understood by those skilled in the art that many modifications can be made without departing from the novel matters and effects of the present invention. Accordingly, all such modifications are intended to be included in the scope of the present invention. For example, a term described at least once together with a different term having a broader meaning or the same meaning in the specification or the drawings can be replaced with the different term in any part of the specification or the drawings. All combinations of the present embodiment and the modified examples are also included in the scope of the present invention. In addition, the configurations and operations of the circuit device, the oscillation device, the physical quantity measuring device, the electronic device, and the moving body are not limited to those described in this embodiment, and various modifications can be made.

5 ... temperature sensor, 10 ... processing unit, 11 ... control unit, 12 ... event control unit,
13 ... random number data output unit, 14 ... encryption processing unit, 21 ... memory, 30 ... timing unit,
31 ... Frequency divider, 32 ... Frequency divider, 33 ... Time data generator, 40 ... Non-volatile memory,
50 ... Power supply control unit, 60 ... Interface unit, 70 ... Interrupt control unit,
80... Oscillation circuit, 81... Amplifier circuit, 82... Adjustment circuit, 90.
DESCRIPTION OF SYMBOLS 100 ... Circuit apparatus, 200 ... External device, 210 ... Processing part,
213 ... random number data output unit, 214 ... encryption processing unit, 220 ... interface unit,
300 ... electronic equipment, 400 ... oscillation device, 410 ... package, 412 ... base portion,
414... Lid section, 500... Circuit device, 501... Circuit device, 502.
510 ... Communication unit, 520 ... Processing unit, 530 ... Operation unit, 540 ... Display unit,
550 ... Storage unit, 600 ... Automobile, 610 ... Communication unit, 620 ... Communication unit,
630 ... Communication unit, 640 ... Gateway device, 700 ... Physical quantity measuring device,
710 ... Oscillator circuit, 720 ... Oscillator circuit, 730 ... Synchronization circuit,
740 ... time digital conversion circuit, 750 ... circuit device,
DA1 ... PUF information, DATA0 to DATA127 ... temperature compensation data,
DB1 ... random number data, OSC ... oscillation signal, XTAL ... oscillator,
XTAL1 ... oscillator, XTAL2 ... oscillator

Claims (17)

An oscillation circuit that generates an oscillation signal using an oscillator;
A processing unit for controlling the oscillation circuit;
An interface unit for outputting authentication information for authenticating the circuit device to an external device, which is information based on unique information of the circuit device;
A circuit device comprising: The circuit device according to claim 1,
A non-volatile memory for storing oscillation adjustment data and the unique information of the oscillation circuit, or storing the oscillation adjustment data as the unique information;
The interface unit is
A circuit device that outputs the authentication information based on the unique information stored in the nonvolatile memory to the external device. The circuit device according to claim 1 or 2,
The interface unit is
Receiving external device authentication information for authenticating the external device;
The processor is
A circuit device that performs authentication processing of the external device based on the external device authentication information. The circuit device according to claim 1,
Including the cryptographic processing part,
The interface unit is
The circuit device, wherein the authentication information encrypted by the encryption processing unit is output to the external device. The circuit device according to claim 3,
A circuit device comprising: an encryption processing unit for decrypting the encrypted external device authentication information. The circuit device according to any one of claims 1 to 5,
Including a random number data output unit for outputting random number data,
The interface unit is
A circuit apparatus, wherein the authentication information generated by a combination of the unique information and the random number data is output to the external device. The circuit device according to claim 6,
The authentication information is:
A circuit device characterized in that the specific information bit is assigned to a given bit of the authentication information and the random number data bit is assigned to another bit of the authentication information. The circuit device according to any one of claims 1 to 5,
The interface unit is
A circuit device that outputs the authentication information generated by a combination of the unique information and circuit characteristic adjustment data. The circuit device according to claim 8, wherein
The authentication information is:
A circuit device characterized in that the specific information bit is assigned to a given bit of the authentication information, and the circuit characteristic adjustment data bit is assigned to another bit of the authentication information. The circuit device according to any one of claims 1 to 9,
The specific information is
A circuit device characterized in that it is PUF (Physically Unclonable Function) information unique to the circuit device. The circuit device according to claim 10, wherein
The PUF information is
A circuit device comprising information generated based on temperature compensation data of an oscillation frequency of the oscillation signal. The circuit device according to any one of claims 1 to 11,
Based on the oscillation signal, including a timekeeping unit that generates timekeeping data that is real-time clock information,
The interface unit is
Outputting the timing data to the external device;
The authentication information is:
The circuit device is information for authenticating the circuit device that outputs the time measurement data. The circuit device according to any one of claims 1 to 11,
A time digital conversion circuit that performs time digital conversion based on the oscillation signal;
The interface unit is
A circuit device that outputs information generated based on the time digital conversion to the external device. A circuit device according to any one of claims 1 to 12,
The oscillator;
An oscillation device comprising: A circuit device according to any one of claims 1 to 11 and claim 13,
The oscillator;
A physical quantity measuring device comprising: A circuit device according to any one of claims 1 to 13,
The external device;
An electronic device comprising: A circuit device according to any one of claims 1 to 13,
The external device;
A moving object comprising:

Images