Two-wire authentication chip

Abstract

The embodiment of the invention provides a two-wire type authentication chip, and relates to the technical field of electronic equipment. The authentication chip comprises an H-bridge circuit used for extracting a communication instruction sent by the host device; the bidirectional communication module is used for analyzing the communication instruction to obtain a communication command sent by the host equipment and transmitting data fed back by the authentication chip based on the communication command; the finite-state machine module is used for scheduling the bidirectional communication module, the memory and the encryption module to execute corresponding functions; the load adjusting module is used for adjusting the self load of the authentication chip; the memory is used for storing data; and the encryption module is used for encrypting data. The cost of the authentication chip can be reduced.

Description

Technical Field

[0001] The embodiments of the present application relate to the technical field of electronic equipment, and in particular to a two-wire authentication chip. Background Art

[0002] In our daily life and work, we often use a large number of consumable products, such as ink cartridges, e-cigarette cartridges, various filters, medical consumables, etc.

[0003] In the prior art, in order to better control the quality of consumable products, various manufacturers usually add authentication chips to consumable products, and use the authentication chips to enable the host device to authenticate the consumable products, thereby achieving quality control of the consumable products.

[0004] However, the inventors found that most existing authentication chips use single-wire or dual-wire communication designs. If a communication interface is added to the original power supply and ground terminals, the number of metal connection points of the consumable product will exceed 3, making production more difficult and increasing production costs.

[0005] It should be noted that the above content is not necessarily prior art, nor is it intended to limit the scope of patent protection of this application. Summary of the invention

[0006] The embodiments of the present application provide a two-wire authentication chip to solve or alleviate one or more of the technical problems mentioned above.

[0007] One aspect of an embodiment of the present application provides a two-wire authentication chip, the authentication chip is installed on a consumable product and is used to communicate with a host device, the authentication chip has two contacts, and the authentication chip includes an H-bridge circuit, a bidirectional communication module, a finite state machine module, a load adjustment module, a memory, and an encryption module; An H-bridge circuit, electrically connected to the two contacts, for extracting a communication instruction sent by the host device; The bidirectional communication module is electrically connected to the H-bridge circuit, the load adjustment module and the finite state machine module, and is used to parse the communication instruction to obtain the communication command sent by the host device, and to transmit the data fed back by the authentication chip based on the communication command; The finite state machine module is electrically connected to the two-way communication module, the memory and the encryption module, and is used to schedule the two-way communication module, the memory and the encryption module to perform corresponding functions; The load adjustment module is electrically connected to the bidirectional communication module and is used to adjust the load of the authentication chip itself; The memory is electrically connected to the finite state machine module and is used to store data; The encryption module is electrically connected to the finite state machine module and is used for encrypting data.

[0008] Optionally, the communication instruction includes a plurality of pulse signals, each pulse signal is used to represent a binary data to be sent, and the bidirectional communication module is further used to measure the high-level pulse width and the low-level pulse width in each pulse signal respectively, and determine the data corresponding to each pulse signal according to the measurement result, wherein when the high-level pulse width and the low-level pulse width in the pulse signal meet a preset condition, the data corresponding to the pulse signal is determined to be "1"; when the high-level pulse width and the low-level pulse width in the pulse signal do not meet the preset condition, the data corresponding to the pulse signal is determined to be "0"; The bidirectional communication module is further used to parse the data corresponding to the plurality of pulse signals according to a preset communication protocol to obtain a communication command sent by the host device.

[0009] Optionally, the two-way communication module is further used to determine the data to be fed back based on the communication command; The finite state machine module is further used to call the encryption module to encrypt the data to be fed back to obtain encrypted data; The bidirectional communication module is also used to return the encrypted data to the host device through the H-bridge circuit.

[0010] Optionally, the finite state machine module is further used to read an encryption key from the memory and send the encryption key to the encryption module; The encryption module is further used to generate a random number based on the data to be fed back, and combine the random number with the data to be fed back to obtain combined data; The encryption module is further used to encrypt the combined data based on the encryption key to obtain the encrypted data.

[0011] Optionally, the bidirectional communication module is further used to extract a plurality of excitation pulses sent by the host device through the H-bridge circuit; The two-way communication module is also used to communicate with the encrypted data according to the preset coding strategy. The plurality of excitation pulses are encoded to obtain encoded pulse data; The bidirectional communication module is also used to return the encoded pulse data to the host device through the H-bridge circuit.

[0012] Optionally, an excitation pulse corresponds to a binary data to be returned to the host device, and the preset encoding strategy is: when the data to be encoded is "1", the excitation pulse corresponding to the current data to be encoded is subjected to high-frequency modulation processing; when the data to be encoded is "0", the excitation pulse corresponding to the current data to be encoded is not processed.

[0013] Optionally, the two excitation pulses correspond to a binary data to be returned to the host device, and the preset encoding strategy is: when the data to be encoded is "1", a first high-frequency modulation process is performed on the first excitation pulse of the two excitation pulses corresponding to the current data to be encoded using a first frequency, and a second high-frequency modulation process is performed on the second excitation pulse of the two excitation pulses corresponding to the current data to be encoded using a second frequency; when the data to be encoded is "0", the two excitation pulses corresponding to the current data to be encoded are not processed.

[0014] Optionally, the three excitation pulses correspond to a binary data to be returned to the host device, and the preset encoding strategy is: when the data to be encoded is "1", the voltage of the high-level pulse in the first excitation pulse and the third excitation pulse of the three excitation pulses corresponding to the current data to be encoded is pulled down; when the data to be encoded is "0", the voltage of the high-level pulse in the second excitation pulse of the three excitation pulses corresponding to the current data to be encoded is pulled down.

[0015] Optionally, the H-bridge circuit is also used to calculate the absolute difference between a first voltage value obtained from the first contact and a second voltage value obtained from the second contact; if the absolute difference is greater than or equal to a preset threshold, it is determined that the currently extracted input signal is a high-level pulse signal; if the absolute difference is less than the preset threshold, it is determined that the currently extracted input signal is a low-level pulse signal.

[0016] Optionally, the load regulation module includes a field effect transistor having an internal resistance greater than a preset resistance value.

[0017] The above technical solution adopted in the embodiment of the present application may have the following advantages: There is no need to add additional communication interface contacts required for the authentication chip, which saves costs. At the same time, the authentication chip in this application can be connected in any forward and reverse directions at the two original contact points of power supply and grounding, without considering the direction of the contact points. In addition, the authentication chip in this application can realize encrypted communication, and during the encryption process, all internal operations are controlled by the internal finite state machine module. Since the finite state machine module is a hardware circuit, compared with software implementation, the security and stability of the entire chip have been greatly improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The accompanying drawings exemplarily illustrate the embodiments and constitute a part of the specification, and together with the text description of the specification, are used to explain the exemplary implementation of the embodiments. The embodiments shown are for illustrative purposes only and do not limit the scope of the claims. In all drawings, the same reference numerals refer to similar but not necessarily identical elements.

[0019] Figure 1 The module diagram of the two-wire authentication chip according to the first embodiment of the present application is schematically shown.

[0020] Figure 2 The module diagram of the main control circuit in one embodiment is schematically shown.

[0021] Figure 3 The module diagram of the main control circuit in another embodiment is schematically shown.

[0022] Figure 4 The figure schematically shows a pulse signal representation diagram corresponding to data “1” in one embodiment.

[0023] Figure 5 The figure schematically shows a pulse signal representation diagram corresponding to data “0” in one embodiment.

[0024] Figure 6 A schematic diagram of pulse signal representation corresponding to data “1” in another embodiment is schematically shown.

[0025] Figure 7 A schematic diagram of pulse signal characterization corresponding to data “0” in another embodiment is schematically shown. DETAILED DESCRIPTION

[0026] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. The components of the embodiments of the present invention generally described and shown in the drawings here can be arranged and designed in various different configurations. The present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present invention more thorough and comprehensive. Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the invention claimed for protection, but merely represents the selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without making creative work belong to the scope of protection of the present invention.

[0027] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0028] In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "disposed", "connected", and "electrically connected" should be understood in a broad sense, for example, it can be directly connected, or indirectly connected through an intermediate medium, or it can be the internal connection of two elements. It should be noted that when an element is considered to be "connected" to another element, it can be directly connected to the other element or there may be an intermediate element at the same time.

[0029] Some embodiments of the present invention are described in detail below in conjunction with the accompanying drawings. In the absence of conflict, the following embodiments and features in the embodiments can be combined with each other.

[0030] Embodiment 1 Figure 1 The module diagram of the two-wire authentication chip according to the first embodiment of the present application is schematically shown.

[0031] The authentication chip is installed on the consumable product and is used to communicate with the host device. The host device is provided with a main control circuit, which has two contacts, namely the first contact and the second contact. The authentication chip also has two contacts, namely the third contact and the fourth contact.

[0032] The host device may be a printer, an electronic cigarette holder, a water dispenser, medical equipment, etc. Correspondingly, the consumable products may be ink cartridges, electronic cigarette cartridges, water dispenser filters, medical consumables, etc.

[0033] When the consumable product is installed on the host device, the two contacts in the main control circuit provided on the host device will be electrically connected to the two contacts in the authentication chip provided on the consumable product respectively, thereby forming a complete communication transmission link.

[0034] In one example, see Figure 2 The main control circuit 100 has a first contact 101 and a second contact 102. When the consumable product is correctly installed on the host device, the two contacts in the main control circuit 100 on the host device are electrically connected to the two contacts in the authentication chip on the consumable product, thereby forming a complete communication transmission link.

[0035] In this embodiment, the main control circuit 100 includes a battery 103 , a main control chip 104 and a switch module 105 .

[0036] The battery 103 may be a built-in rechargeable battery or a detachable non-rechargeable battery. The battery 103 is used to supply power to the main control circuit 100 and the authentication chip.

[0037] The main control chip 104 is used to encode the data sent by the main control circuit 100 and decode the data returned by the authentication circuit 200. The main control chip 104 can be a chip such as an MCU, a CPU, or a field programmable gate array (FPGA).

[0038] The switch module 105 is used to realize opening and closing under the control of the main control chip 104. The switch module 105 includes a field effect transistor or a triode.

[0039] In this embodiment, the first pin 1041 of the main control chip 104 and the first end 1051 of the switch module 105 are both electrically connected to one end (positive or negative) of the battery 103. The second pin 1042 of the main control chip 104 is electrically connected to the second end 1052 of the switch module 105. The third pin 1043 of the main control chip 104 and the other end (negative or positive) of the battery 103 are both electrically connected to the second contact 102. The third end 1053 of the switch module 105 is electrically connected to the first contact 101, and the second end 1052 of the switch module 105 is a control end.

[0040] In another example, see Figure 3 The main control circuit 100' has a first contact 101' and a second contact 102'. When the consumable product is correctly installed on the host device, the two contacts in the main control circuit 100 on the host device will be electrically connected to the two contacts in the authentication chip on the consumable product, thereby forming a complete communication transmission link.

[0041] In this embodiment, the main control circuit 100 ′ includes a battery 103 ′, a main control chip 104 ′, a switch module 105 ′ and a filter module 106 ′.

[0042] The battery 103' can be a built-in rechargeable battery or a detachable non-rechargeable battery. The battery 103' is used to supply power to the main control circuit 100' and the authentication chip.

[0043] The main control chip 104' is used to encode the data sent by the main control circuit 100' and decode the data returned by the authentication chip. The main control chip 104' can be a chip such as MCU, CPU, field programmable gate array (FPGA), etc.

[0044] The switch module 105' is used to realize opening and closing under the control of the main control chip 104'. The switch module 105' includes a field effect transistor or a triode.

[0045] The filter module 106' is used for filtering, wherein the filter module 106' is preferably a high-frequency filter module.

[0046] In this embodiment, the first pin 1041' of the main control chip 104' and the first end 1051' of the switch module 105' are both electrically connected to one end (positive or negative) of the battery 103'. The second pin 1042' of the main control chip 104' is electrically connected to the second end 1052' of the switch module 105'. The third pin 1043' of the main control chip 104' is electrically connected to the first end 1061' of the filter module 106'. The fourth pin 1044' of the main control chip 104', the other end (negative or positive) of the battery 103', and the second end 1062' of the filter module 106' are all electrically connected to the second contact 102'. The third end 1053' of the switch module 105' and the third end 1063' of the filter module 106' are both electrically connected to the first contact 101', and the second end 1052' of the switch module 105' is the control end.

[0047] In an optional embodiment, when the main control circuit 100 (100') sends a communication instruction to the authentication chip, the main control chip 104 (104') in the main control circuit 100 (100') controls the switch module 105 (105') to open and close in a first preset manner, generates a communication instruction consisting of a plurality of first signals, and transmits the communication instruction to the authentication chip through two contacts of the main control circuit 100 (100').

[0048] In this embodiment, when the main control circuit sends a communication instruction to the authentication chip, each to-be-sent data contained in the communication instruction may be encoded using a coding method such as Morse code or Manchester code.

[0049] Correspondingly, the first preset mode includes the setting of the switch module control mode corresponding to the data "1" and the setting of the switch module control mode corresponding to the data "0". The setting of the switch module control mode corresponding to the data "1" and the setting of the switch module control mode corresponding to the data "0" can be set according to actual conditions, and the specific control mode is not limited in this embodiment.

[0050] It should be noted that when different encoding methods are used to encode the data to be sent, the first preset method should also correspond to the encoding method used.

[0051] In one example, when Morse code is used to encode the data to be transmitted, the time required to transmit one bit of data (hereinafter referred to as bit time) can be divided into two time periods of unequal length, for example, a time period of one quarter of a bit time and a time period of three quarters of a bit time. Since the voltage (also called level) of each time period can be high or low, when the data to be transmitted is data "1", the data "1" can be represented by a first pulse signal consisting of a high level pulse of three quarters of a bit time in the first time period and a low level pulse of one quarter of a bit time in the second time period, such as Figure 4 When the data to be sent is data "0", the data "0" can be set to be represented by a second pulse signal consisting of a low-level pulse with a first time period of 3 / 4 bit time and a high-level pulse with a second time period of 1 / 4 bit time, as shown in FIG. Figure 5 shown.

[0052] It should be noted that the representation of data "0" and data "1" may also be the opposite of the above description.

[0053] In addition, it should be noted that in order to improve interference resistance, the representation method of data "0" and data "1" can also be represented by the multiple pulse signals described above. For example, data "0" and data "1" are represented by the two pulse signals described above, that is, data "0" is represented by the two second pulse signals, and data "1" is represented by the two first pulse signals.

[0054] In one example, when Manchester coding is used to encode the data to be transmitted, the time required to transmit one bit of data (hereinafter referred to as bit time) can be divided into two time periods of equal length. Since the voltage (also called level) of each time period can be high or low, when the data to be transmitted is data "1", the data "1" can be represented by a third pulse signal consisting of a high level pulse in the first time period and a low level pulse in the second time period, such as Figure 6 When the data to be sent is data "0", the data "0" can be set to be represented by a fourth pulse signal consisting of a low-level pulse in the first time period and a high-level pulse in the second time period, such as Figure 7 shown.

[0055] It should be noted that in order to improve the interference resistance, the representation method of data "0" and data "1" can also be represented by the multiple pulse signals described above. For example, data "0" and data "1" are represented by the two pulse signals described above, that is, data "0" is represented by the two fourth pulse signals, and data "1" is represented by the two third pulse signals.

[0056] It can be understood that when the data to be sent is encoded using the Morse code described in the above example, when the data to be sent is "1", the main control chip 104 (104') will control the switch module 105 (105') to be in a closed state during the first three quarters of the bit time, and control the switch module 105 (105') to be in an open state during the second quarter of the bit time, thereby encoding the power signal into the first signal corresponding to the data to be sent "1". Similarly, when the data to be sent is "0", the main control chip 104 (104') will control the switch module 105 (105') to be in an open state during the first three quarters of the bit time, and control the switch module 105 (105') to be in a closed state during the second quarter of the bit time, thereby encoding the power signal into the first signal corresponding to the data to be sent "0".

[0057] It should be noted that when multiple data to be sent need to be sent, the main control chip 104 (104') will control the opening and closing time of the switch module 105 (105') in the above manner for each data to be sent.

[0058] like Figure 1 As shown, the authentication chip includes an H-bridge circuit 200 , a bidirectional communication module 201 , a finite state machine module 202 , a load adjustment module 203 , a memory 204 and an encryption module 205 .

[0059] The H-bridge circuit 200 is electrically connected to the two contacts and is used to extract the communication instructions sent by the host device.

[0060] The bidirectional communication module 201 is electrically connected to the H-bridge circuit 200, the load adjustment module 203 and the finite state machine module 202, and is used to parse the communication instructions, obtain the communication commands sent by the host device, and transmit the data fed back by the authentication chip based on the communication commands.

[0061] The finite state machine module 202 is electrically connected to the two-way communication module 201, the memory 204 and the encryption module 205, and is used to schedule the two-way communication module, the memory and the encryption module to perform corresponding functions; The load adjustment module 203 is electrically connected to the bidirectional communication module 201 and is used to adjust the load of the authentication chip itself; The memory 204 is electrically connected to the finite state machine module 202 and is used to store data; The encryption module 205 is electrically connected to the finite state machine module 202 and is used for encrypting data.

[0062] The authentication chip in this application does not need to add additional communication interface contacts required by the authentication chip, saving costs. At the same time, the authentication chip in this application can be connected in either forward or reverse directions at the two original contact points of power supply and ground, without considering the direction of the contact points. In addition, the authentication chip in this application can realize encrypted communication, and during the encryption process, all internal operations are controlled by the internal finite state machine module. Since the finite state machine module is a hardware circuit, the security and stability of the entire chip are greatly improved compared to software implementation.

[0063] In an optional embodiment, the communication instruction includes multiple pulse signals, each pulse signal is used to represent a binary data to be sent, and the two-way communication module 201 is also used to measure the high-level pulse width and the low-level pulse width in each pulse signal respectively, and determine the data corresponding to each pulse signal according to the measurement results, wherein when the high-level pulse width and the low-level pulse width in the pulse signal meet the preset conditions, the data corresponding to the pulse signal is determined to be "1"; when the high-level pulse width and the low-level pulse width in the pulse signal do not meet the preset conditions, the data corresponding to the pulse signal is determined to be "0".

[0064] After obtaining the measurement results of each pulse signal, the authentication chip will determine whether the high-level pulse width and the low-level pulse width in the pulse signal meet the preset conditions according to the decoding rules pre-stored in the memory 204. When the high-level pulse width and the low-level pulse width in the pulse signal meet the preset conditions, it can be determined that the data corresponding to the pulse signal is "1"; when the high-level pulse width and the low-level pulse width in the pulse signal do not meet the preset conditions, it is determined that the data corresponding to the pulse signal is "0".

[0065] The preset condition is a condition required in a decoding rule for determining that the data corresponding to a pulse signal is "1". For example, the preset condition is that the high-level pulse width in the pulse signal accounts for three quarters.

[0066] The bidirectional communication module 201 is further used to parse the data corresponding to the plurality of pulse signals according to a preset communication protocol to obtain a communication command sent by the host device.

[0067] The communication protocol is used to define communication commands corresponding to different binary combination data.

[0068] After obtaining the binary combination data corresponding to all the pulse signals contained in the communication instruction, the two-way communication module 201 will parse it according to the communication protocol to obtain the communication command sent by the host device. For example, the communication command obtained by parsing is: "The authentication chip needs to feedback the remaining available time of consumable products."

[0069] In an optional embodiment, the two-way communication module 201 is further used to determine the data to be fed back based on the communication command.

[0070] The finite state machine module 202 is further used to call the encryption module 205 to encrypt the data to be fed back to obtain encrypted data.

[0071] The bidirectional communication module 201 is further configured to return the encrypted data to the host device via the H-bridge circuit 200 .

[0072] In this embodiment, after the two-way communication module 201 parses and obtains the communication command, it determines the data to be fed back through the finite state machine module 202 and returns the data to be fed back to the two-way communication module 201 .

[0073] After the two-way communication module 201 obtains the data to be fed back, if the data to be fed back is data that needs to be encrypted, the finite state machine module 202 will also call the encryption module 205 to encrypt the data to be fed back to obtain the encrypted data. If the data to be fed back does not need to be encrypted, the finite state machine module 202 will not call the encryption module 205 to encrypt the data to be fed back. Whether the data to be fed back needs to be encrypted can be determined according to the communication command.

[0074] After completing the encryption of the data to be fed back, the encryption module 205 will return the encrypted data to the two-way communication module 201 through the finite state machine module 202. After receiving the data, the two-way communication module 201 can return the encrypted data to the host device through the H-bridge circuit 201.

[0075] In an optional embodiment, the finite state machine module 202 is further configured to read an encryption key from the memory and send the encryption key to the encryption module 205 .

[0076] The encryption module 205 is further used to generate a random number based on the data to be fed back, and combine the random number with the data to be fed back to obtain combined data; The encryption module 205 is further configured to encrypt the combined data based on the encryption key to obtain the encrypted data.

[0077] In this embodiment, when encryption is performed, the encryption key stored in the memory is taken out, and a random number is generated according to the authenticated content data (data to be fed back) to perform encryption authentication. All internal operations are controlled by the finite state machine module 202, and the finite state machine module 202 is a hardware circuit. Compared with software implementation, the security and stability of the entire chip are greatly improved. In addition, by adding random numbers for encryption, the security of encryption can be further improved.

[0078] In an optional embodiment, the bidirectional communication module 201 is further configured to communicate with the H-bridge circuit 20 0 extracts multiple excitation pulses sent by the host device.

[0079] The two-way communication module 201 is also used to transmit the encrypted data according to the preset coding strategy. The plurality of excitation pulses are coded to obtain coded pulse data.

[0080] The bidirectional communication module 201 is also used to return the encoded pulse data to the host device through the H-bridge circuit 200.

[0081] In this embodiment, the excitation pulse is generated by the main control chip controlling the switch module to be opened and closed according to the second preset mode. The second preset mode includes setting the time period during which the switch module is in an open or closed state within a data transmission cycle of one bit. The data transmission cycle includes a data preparation time period, a data modulation time period, and a data transmission completion time period. The data preparation time period is used for the authentication chip to prepare the data to be sent. The data modulation time period is used for the authentication chip to modulate the data to be sent. The data transmission completion time period is used for the authentication chip to transmit information that the modulation of the data to be sent has been completed.

[0082] In one example, the second preset mode is: the switch module 105 is in a closed state in the first one-fifth of the cycle in the data transmission cycle, in a closed state in the middle three-fifths of the cycle, and in an open state in the last one-fifth of the cycle. In another example, the second preset mode is: in a closed state in the first one-tenth of the cycle in the data transmission cycle, in a closed state in the middle seven-tenths of the cycle, and in an open state in the last two-tenths of the cycle.

[0083] In an optional implementation, an excitation pulse corresponds to a binary data to be returned to the host device, and the preset encoding strategy is: when the data to be encoded is "1", the excitation pulse corresponding to the current data to be encoded is subjected to high-frequency modulation processing; when the data to be encoded is "0", the excitation pulse corresponding to the current data to be encoded is not processed.

[0084] Among them, high-frequency modulation processing refers to using a high-frequency signal to modulate the high-level pulse signal in the excitation pulse corresponding to the current data to be encoded, thereby encoding the high-level pulse in the excitation pulse into a carrier signal with a frequency greater than the frequency of the excitation pulse, thereby generating encoded pulse data.

[0085] In an optional embodiment, two excitation pulses correspond to a binary data to be returned to the host device, and the preset encoding strategy is: when the data to be encoded is "1", a first high-frequency modulation process is performed on the first excitation pulse of the two excitation pulses corresponding to the current data to be encoded using a first frequency, and a second high-frequency modulation process is performed on the second excitation pulse of the two excitation pulses corresponding to the current data to be encoded using a second frequency; when the data to be encoded is "0", the two excitation pulses corresponding to the current data to be encoded are not processed.

[0086] In this embodiment, the two excitation pulses are modulated respectively using carrier signals of different frequencies, so that when the encoded pulse data is subsequently decoded, the modulation signals corresponding to the two excitation pulses can be combined for decoding to determine whether the data sent by the authentication chip is "1" or "0", thereby better avoiding environmental interference.

[0087] It should be noted that when the host device receives the encoded pulse data, it can use Figure 3 The filter module in the main control circuit shown detects a high-frequency signal from the encoded pulse data, and then the high-frequency signal can be processed by an analog-to-digital converter or a comparator integrated inside the main control chip to obtain data returned by the authentication chip.

[0088] It should be noted that, when processing, the modulation methods used for the data to be encoded are different, and the processing methods are also different. For example, when the modulation methods used for the encoded data "1" and "0" are respectively: high-frequency modulation processing is performed on the data "1", and no processing is performed on the data "0", then when decoding processing is performed, a comparator can be used. When the comparator detects a high-frequency signal, it can be determined that the data returned by the authentication chip is "1", and when the comparator does not detect a high-frequency signal, it can be determined that the data returned by the authentication chip is "0". For another example, when the modulation methods used for the encoded data "1" and "0" are respectively: a first high-frequency modulation processing is performed on the data "1" (the carrier frequency is the first frequency), and a second high-frequency modulation processing is performed on the data "0" (the carrier frequency is the second frequency), then when decoding processing is performed, an analog-to-digital converter can be used to obtain the frequency of the high-frequency signal. When the frequency is the first frequency, it can be determined that the data returned by the authentication chip 204 is "1"; when the frequency is the second frequency, it can be determined that the data returned by the authentication chip 204 is "0".

[0089] In an optional implementation, three excitation pulses correspond to a binary data to be returned to the host device, and the preset encoding strategy is: when the data to be encoded is "1", the voltage of the high-level pulse in the first excitation pulse and the third excitation pulse of the three excitation pulses corresponding to the current data to be encoded is pulled down; when the data to be encoded is "0", the voltage of the high-level pulse in the second excitation pulse of the three excitation pulses corresponding to the current data to be encoded is pulled down.

[0090] It should be noted that when the host device receives the encoded pulse data, it can use Figure 2 The main control circuit shown decodes the encoded pulse data. Specifically, when decoding, the main control chip takes every three pulse data as a group, and for each group of pulse data, calculates the voltage average of the high-level pulses in the first excitation pulse and the third excitation pulse, and measures the voltage value of the high-level pulse in the second excitation pulse, and then compares the calculated voltage average with the voltage value. If the voltage average is less than the voltage value, it can be determined that the data represented by this group of pulse data is "1"; if the voltage average is greater than the voltage value, it can be determined that the data represented by this group of pulse data is "0".

[0091] In this embodiment, since there will be noise and interference in the circuit during actual application, in order to filter the noise and interference to improve the stability of the circuit, when the main control circuit reads one bit of data from the authentication chip, it will use multiple excitation pulses to encode one bit of data to generate feedback data corresponding to each bit of data, thereby reducing the impact of the battery voltage drop.

[0092] In an optional embodiment, the H-bridge circuit is also used to calculate the absolute difference between a first voltage value obtained from the first contact and a second voltage value obtained from the second contact; if the absolute difference is greater than or equal to a preset threshold, it is determined that the currently extracted input signal is a high-level pulse signal; if the absolute difference is less than the preset threshold, it is a low-level pulse signal.

[0093] The preset threshold is a pre-set value, which can be set and modified according to actual conditions. For example, the preset threshold is 0.1V.

[0094] It should be noted that when determining whether the currently extracted input signal is a high-level pulse signal or a low-level pulse signal, the process can also be reversed, that is, if the absolute difference between the two signals is greater than the preset threshold, it is determined that the currently extracted input signal is a low-level pulse signal, otherwise it is determined that the currently extracted input signal is a high-level pulse signal.

[0095] In this embodiment, the H-bridge circuit determines whether the input signal is a high-level pulse signal or a low-level pulse signal based on the absolute difference between the two contacts, so that the authentication chip can support positive and negative connection.

[0096] In an optional embodiment, the load adjustment module includes a field effect tube with an internal resistance greater than a preset resistance value. The authentication chip adjusts the load of the authentication chip itself by controlling the conduction and cutoff of the field effect tube.

[0097] In an optional embodiment, the load regulation module may also be a high-frequency ring oscillator circuit or a digital logic circuit.

[0098] The authentication chip in this embodiment changes the load characteristics of the entire circuit by changing its own load characteristics, thereby achieving the purpose of reverse transmission of data according to the change in the voltage of the power supply signal.

[0099] It should be noted that the above are only preferred embodiments of the present application, and the patent protection scope of the present application is not limited thereto. Any equivalent structure or equivalent process transformation made using the contents of the specification and drawings of the present application, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A two-wire authentication chip, characterized in that: The authentication chip is installed on the consumable product and is used to communicate with the host device. The authentication chip has two contacts and includes an H-bridge circuit, a bidirectional communication module, a finite state machine module, a load adjustment module, a memory and an encryption module; An H-bridge circuit, electrically connected to the two contacts, for extracting a communication instruction sent by the host device; The bidirectional communication module is electrically connected to the H-bridge circuit, the load adjustment module and the finite state machine module, and is used to parse the communication instruction to obtain the communication command sent by the host device, and to transmit the data fed back by the authentication chip based on the communication command; The finite state machine module is electrically connected to the two-way communication module, the memory and the encryption module, and is used to schedule the two-way communication module, the memory and the encryption module to perform corresponding functions; The load adjustment module is electrically connected to the bidirectional communication module and is used to adjust the load of the authentication chip itself; The memory is electrically connected to the finite state machine module and is used to store data; The encryption module is electrically connected to the finite state machine module and is used for encrypting data.

2. The two-wire authentication chip according to claim 1, characterized in that: The communication instruction includes a plurality of pulse signals, each pulse signal is used to represent a binary data to be sent, and the two-way communication module is further used to measure the high-level pulse width and the low-level pulse width in each pulse signal respectively, and determine the data corresponding to each pulse signal according to the measurement result, wherein when the high-level pulse width and the low-level pulse width in the pulse signal meet the preset condition, the data corresponding to the pulse signal is determined to be "1"; when the high-level pulse width and the low-level pulse width in the pulse signal do not meet the preset condition, the data corresponding to the pulse signal is determined to be "0"; The bidirectional communication module is further used to parse the data corresponding to the plurality of pulse signals according to a preset communication protocol to obtain a communication command sent by the host device.

3. The two-wire authentication chip according to claim 1 or 2, characterized in that: The two-way communication module is further used to determine the data to be fed back based on the communication command; The finite state machine module is further used to call the encryption module to encrypt the data to be fed back to obtain encrypted data; The bidirectional communication module is also used to return the encrypted data to the host device through the H-bridge circuit.

4. The two-wire authentication chip according to claim 3, characterized in that: The finite state machine module is further used to read the encryption key from the memory and send the encryption key to the encryption module; The encryption module is further used to generate a random number based on the data to be fed back, and combine the random number with the data to be fed back to obtain combined data; The encryption module is further used to encrypt the combined data based on the encryption key to obtain the encrypted data.

5. The two-wire authentication chip according to claim 3, characterized in that: The bidirectional communication module is further used to extract multiple excitation pulses sent by the host device through the H-bridge circuit; The two-way communication module is also used to communicate with the encrypted data according to the preset coding strategy. The plurality of excitation pulses are encoded to obtain encoded pulse data; The bidirectional communication module is also used to return the encoded pulse data to the host device through the H-bridge circuit.

6. The two-wire authentication chip according to claim 5, characterized in that: One excitation pulse corresponds to one binary data to be returned to the host device, and the preset encoding strategy is: when the data to be encoded is "1", the excitation pulse corresponding to the current data to be encoded is subjected to high-frequency modulation processing; When the data to be encoded is "0", the excitation pulse corresponding to the current data to be encoded is not processed.

7. The two-wire authentication chip according to claim 5, characterized in that: The two excitation pulses correspond to a binary data to be returned to the host device, and the preset encoding strategy is: when the data to be encoded is "1", a first high-frequency modulation process is performed on the first excitation pulse of the two excitation pulses corresponding to the current data to be encoded using a first frequency, and a second high-frequency modulation process is performed on the second excitation pulse of the two excitation pulses corresponding to the current data to be encoded using a second frequency; When the data to be encoded is "0", the two excitation pulses corresponding to the current data to be encoded are not processed.

8. The two-wire authentication chip according to claim 5, characterized in that: The three excitation pulses correspond to a binary data to be returned to the host device, and the preset encoding strategy is: when the data to be encoded is "1", the voltage of the high-level pulse in the first excitation pulse and the third excitation pulse of the three excitation pulses corresponding to the current data to be encoded is pulled down; when the data to be encoded is "0", the voltage of the high-level pulse in the second excitation pulse of the three excitation pulses corresponding to the current data to be encoded is pulled down.

9. The two-wire authentication chip according to claim 2, characterized in that: The H-bridge circuit is further used to calculate an absolute difference between a first voltage value obtained from the first contact and a second voltage value obtained from the second contact; if the absolute difference is greater than or equal to a preset threshold, it is determined that the currently extracted input signal is a high-level pulse signal; If the absolute difference is smaller than a preset threshold, it is determined that the currently extracted input signal is a low-level pulse signal.

10. The two-wire authentication chip according to claim 1, characterized in that: The load regulation module includes a field effect transistor whose internal resistance is greater than a preset resistance value.

Images