Security mechanism circuit and mainboard

Abstract

The invention discloses a security mechanism circuit and a mainboard. The safety mechanism circuit is arranged in a mainboard. The mainboard comprises a connector which is used for being connected with a functional module. The safety mechanism circuit comprises a detection circuit, a control circuit and an operation circuit. When the functional module is connected with the connector and a specific function is started, the control circuit sets the voltage level of the specific node to be a set level. When the voltage level of the contact end is not equal to a preset level, the detection circuit sets the voltage level of the specific node not to be the set level, and the operation circuit executes a safety action. When the voltage level of the contact end is equal to the preset level, the operation circuit does not execute the safety action.

Description

Technical Field

[0001] This invention relates to a security mechanism circuit, and more particularly to a security mechanism circuit for automatically diagnosing the status of a connector. Background Technology

[0002] A typical connector, after being connected to an external device, can receive signals from that device and provide signals from the external device to a processor. However, if the external device cannot be fully connected to the connector due to vibration or improper assembly, the connector will be unable to receive signals from the external device or will transmit incorrect signals to the processor, causing the processor to malfunction or mistakenly believe that the external device is faulty. Summary of the Invention

[0003] An embodiment of the present invention provides a safety mechanism circuit disposed in a motherboard. The motherboard includes a connector for connecting a functional module. The safety mechanism circuit of the present invention includes a detection circuit, a control circuit, and an operation circuit. The detection circuit is coupled between a contact end of the connector and a specific node. When the functional module is connected to the connector and a specific function is enabled, the control circuit sets the voltage level of the specific node to a preset level. The operation circuit operates in a normal mode or a safety mode according to the voltage level of the specific node. When the functional module is connected to the connector, the functional module is electrically connected to the contact end, and the detection circuit detects the voltage level of the contact end. When the voltage level of the contact end is not equal to a preset level, the detection circuit sets the voltage level of the specific node to be different from the preset level, and the operation circuit enters the safety mode. In the safety mode, the operation circuit performs a safety action. When the voltage level of the contact end is equal to the preset level, the operation circuit enters the normal mode. In the normal mode, the operation circuit does not perform a safety action.

[0004] The present invention also provides a motherboard including a connector and a safety mechanism circuit. The connector is used to couple a functional module and includes a first transmission end, a second transmission end, and a plurality of third transmission ends. The first transmission end is electrically connected to the functional module and a first contact end. The second transmission end is electrically connected to the functional module and a second contact end. The third transmission end is located between the first and second transmission ends. The safety mechanism circuit is used to determine whether a connection state between the functional module and the connector is abnormal, and includes a detection circuit, a control circuit, and an operation circuit. The detection circuit is coupled to the first contact end, the second contact end, and a specific node. When the functional module is connected to the connector and a specific function is enabled, the control circuit sets the voltage level of the specific node to a preset level. The operation circuit operates in a normal mode or a safety mode according to the voltage level of the specific node. When the functional module is connected to the connector, the functional module is electrically connected to the first and second contact ends, and the detection circuit detects the voltage levels of the first and second contact ends. When the voltage level of the first or second contact end is not equal to a first preset level, it indicates an abnormal connection state, and the detection circuit sets the voltage level of the specific node to a level other than the preset level. When the voltage levels at the first and second contact terminals are equal to the first preset level, the connection is considered normal. If the connection is abnormal, the operating circuit will perform a safety action. If the connection is normal, the operating circuit will not perform a safety action. Attached Figure Description

[0005] Figure 1A This is a schematic diagram of the control system of the present invention.

[0006] Figure 1B This is another schematic diagram of the control system of the present invention.

[0007] Figure 2 This is a schematic diagram of the operation of the safety mechanism circuit of the present invention.

[0008] [Symbol Explanation]

[0009] 100A, 100B: Control System

[0010] 101A, 101B: Motherboard

[0011] 102: Sub-board

[0012] 110A, 110B: Safety mechanism circuit

[0013] 111: Control Circuit

[0014] 112A, 112B: Detection circuit

[0015] 113: Operating Circuit

[0016] 114: Microcontroller

[0017] 115: Power supply circuit

[0018] 120A, 120B: Connectors

[0019] F1~FN, P1~PN: Transmission end

[0020] GND: Ground terminal

[0021] D1~D3: Contact ends

[0022] ND: Specific node

[0023] Q1~Q4: Transistors

[0024] R1~R3: Resistors

[0025] VCC, VSS: Operating voltage

[0026] VIN: Input voltage

[0027] VBA: Power Supply

[0028] T1~T5: Time points

[0029] 210, 220, 230: Period Detailed Implementation

[0030] To make the objectives, features, and advantages of this invention more apparent and understandable, embodiments are provided below in conjunction with the accompanying drawings for detailed description. This specification provides different embodiments to illustrate the technical features of different implementations of the invention. The configuration of the elements in the embodiments is for illustrative purposes only and is not intended to limit the invention. Furthermore, the repetition of some reference numerals in the embodiments is for simplification and does not imply any correlation between different embodiments.

[0031] Figure 1A This is a schematic diagram of the control system of the present invention. As shown, the control system 100A includes a motherboard (MB) 101A and a daughterboard (DB) 102. The present invention does not limit the type of daughterboard 102. In one possible embodiment, daughterboard 102 is a functional module, such as an advanced driver assistance system (ADAS), an in-vehicle infotainment (IVI) system, or a vehicle control unit (VCU).

[0032] In this embodiment, the daughter board 102 has multiple transmission terminals F1 to FN for transmitting signals to the motherboard 101A or receiving signals from the motherboard 101A. The transmission terminals F1 to FN are arranged sequentially. In one possible embodiment, at least one of the transmission terminals F1 to FN is coupled to a ground terminal GND. For example, transmission terminals F1 and FN are coupled to the ground terminal GND. In this embodiment, the transmission terminals F1 to FN have a gold finger shape, but this is not intended to limit the invention. The invention does not limit the shape of the transmission terminals F1 to FN. As long as the transmission terminals F1 to FN can transmit signals, voltages, or currents, the transmission terminals F1 to FN can have any shape. In one possible embodiment, the shape of the transmission terminals F1 to FN is circular. Furthermore, the shape of one of the transmission terminals F1 to FN may differ from the shape of the other transmission terminals F1 to FN.

[0033] Motherboard 101A includes a safety mechanism circuit 110A and a connector 120A. Connector 120A is used to couple to daughterboard 102. In one possible embodiment, connector 120A has a plurality of transmitting terminals P1 to PN and a contact terminal D1. The transmitting terminals P1 to PN are arranged sequentially. Contact terminal D1 is electrically connected to one of the transmitting terminals P1 to PN. In this embodiment, contact terminal D1 is electrically connected to transmitting terminal P1 (or the first transmitting terminal). When daughterboard 102 is connected to connector 120A, transmitting terminals F1 to FN are electrically connected to transmitting terminals P1 to PN one-to-one. Figure 1A In this invention, the transmitting terminals P1 to PN have a gold finger shape, but this is not intended to limit the invention. The invention does not limit the shape of the transmitting terminals P1 to PN. As long as the transmitting terminals P1 to PN can transmit signals, voltage, or current, they can have any shape. In one possible embodiment, the transmitting terminals P1 to PN are circular.

[0034] In this embodiment, the shapes of the transmitting terminals P1 to PN are the same as those of the transmitting terminals F1 to FN, but this is not intended to limit the invention. As long as the daughterboard 102 is connected to the connector 120A, the shapes of the transmitting terminals P1 to PN may differ from those of the transmitting terminals F1 to FN. Furthermore, the shape of one of the transmitting terminals P1 to PN may differ from the shape of the other.

[0035] The safety mechanism circuit 110A determines whether the connector 120A can transmit signals normally and whether the daughter board 102 has detached. For example, when the daughter board 102 is poorly assembled or in extreme environments such as high or low temperatures or high humidity, it may detach from the connector 120A or be incompletely connected. In this case, the connector 120A will be unable to transmit signals from the daughter board 102 to the safety mechanism circuit 110A or transmit signals from the safety mechanism circuit 110A to the daughter board 102. Furthermore, when the connector 120A is poorly manufactured or designed, it may have insufficient solder, resulting in solder cracks, which will prevent the connector 120A from transmitting signals normally. In this embodiment, when the safety mechanism circuit 110A detects an abnormality (such as a faulty connector 120A or a detached daughter board 102), it executes a safety action to prevent the control system 100A from malfunctioning.

[0036] This invention does not limit the architecture of the motherboard 101A. In other embodiments, the motherboard 101A further includes at least one Ethernet switch, at least one PCIe switch, and at least one communication interface. The communication interface may include a Controller Area Network (CAN), a Local Interconnect Network (LIN), or an automotive Ethernet network, conforming to the 100BASE-T1 or 1000BASE-T1 transmission protocol.

[0037] In this embodiment, the security mechanism circuit 110A includes a control circuit 111, a detection circuit 112A, and an operation circuit 113. The control circuit 111 is used to set the voltage level of a specific node ND. In one possible embodiment, when the daughter board 102 is connected to the connector 120A and a specific function is enabled, the control circuit 111 sets the voltage level of the specific node ND to a set level, such as a high level. In some embodiments, the control circuit 111 detects the voltage level of at least one of the transmission terminals P1 to PN to determine whether the daughter board 102 is connected to the connector 120A.

[0038] The detection circuit 112A is coupled between the contact terminal D1 and the specific node ND. Based on the voltage level of the contact terminal D1, the detection circuit 112A determines whether an abnormality has occurred, such as a fault in connector 120A or an abnormal connection between daughterboard 102 and connector 120A. Based on the determination result, the detection circuit 112A sets the voltage level of the specific node ND.

[0039] For example, when the voltage level at contact D1 is not equal to a first preset level, it indicates an abnormality. Therefore, detection circuit 112A sets the voltage level of specific node ND to be not equal to a preset level. In this case, detection circuit 112A may set the voltage level of specific node ND to a low level. However, when the voltage level at contact D1 is equal to the first preset level, it indicates no abnormality has occurred. Therefore, detection circuit 112A does not set the voltage level of specific node ND. In this case, the voltage level of specific node ND may be equal to a preset level, such as a high level.

[0040] This invention does not limit the architecture of the detection circuit 112A. Any circuit that can set the voltage level of a specific node ND based on the voltage level of the contact terminal D1 can be used as the detection circuit 112A. In this embodiment, the detection circuit 112A includes a transistor Q1 and a resistor R1. The gate of transistor Q1 is coupled to the contact terminal D1, its drain is coupled to the specific node ND, and its source receives an operating voltage VSS. Resistor R1 receives an operating voltage VCC. In one possible embodiment, the operating voltage VCC is greater than the operating voltage VSS.

[0041] When daughterboard 102 is normally connected to connector 120A, the voltage at contact point D1 is equal to the voltage at ground point GND, such as 0V. Therefore, transistor Q1 is not conducting. However, when the connection between daughterboard 102 and connector 120A is abnormal, or when connector 120A fails, the voltage at contact point D1 is not equal to the voltage at ground point GND. In this case, since the gate voltage of transistor Q1 is approximately equal to the operating voltage VCC, transistor Q1 conducts. Therefore, the voltage at a specific node ND is equal to the operating voltage VSS.

[0042] In other embodiments, the detection circuit 112A further detects the voltage level of a contact terminal D2 of the connector 120A. Contact terminal D2 is electrically connected to the transmitting terminal PN. In this example, when the daughter board 102 is inserted into the connector 120A, since the transmitting terminals F1 and FN are coupled to the ground terminal GND, the voltage levels of contacts D1 and D2 are equal to the voltage level of the ground terminal GND. However, when the voltage level of contact terminal D2 is not equal to the voltage level of the ground terminal GND (or a first preset level), it indicates an abnormal connection between the daughter board 102 and the connector 120A, or a fault in the connector 120A. Therefore, the detection circuit 112A causes the voltage level of a specific node ND to be different from a set level.

[0043] In some embodiments, the detection circuit 112A further includes a transistor Q2 and a resistor R2. The gate of transistor Q2 is coupled to contact terminal D2, its drain is coupled to a specific node ND, and its source receives the operating voltage VSS. Resistor R2 receives the operating voltage VCC. When the connection between daughterboard 102 and connector 120A is normal, the voltage level at contact terminal D2 is equal to a first preset value (such as the voltage value of ground terminal GND). Therefore, transistor Q2 is not turned on. However, when the connection between daughterboard 102 and connector 120A is incomplete, or when connector 120A is faulty, the voltage level at contact terminal D2 is not equal to the first preset value. Therefore, the gate voltage of transistor Q2 is equal to the operating voltage VCC, so transistor Q2 is turned on, making the voltage at the specific node ND equal to the operating voltage VSS.

[0044] In one possible embodiment, contacts D1 and D2 are located on opposite sides of connector 120A to detect incomplete disconnection. For example, when the voltage at contact D1 is not equal to the voltage at ground GND while the voltage at contact D2 is equal to the voltage at ground GND, it indicates that one side of daughterboard 102 has disconnected from connector 120A, causing transmission terminal P1 to no longer contact transmission terminal F1. Therefore, detection circuit 112A sets the voltage level of a specific node ND to be different from a set level. In one possible embodiment, transmission terminals P2 to PN-1 (or the third transmission terminal) of connector 120A are located between transmission terminals P1 and PN.

[0045] Because the detection circuit 112A diagnoses the connection status of connector 120A in real time, when daughter board 102 is completely or partially disconnected from both sides of connector 120A, the detection circuit 112A can immediately react (by changing the voltage level of a specific node ND) based on the voltage levels of contact terminals D1 and D2. In some embodiments, the detection circuit 112A may detect an abnormal connection status between daughter board 102 and connector 120A within 7.4 µs.

[0046] The operating circuit 113 operates in either a normal mode or a safety mode based on the voltage level of a specific node ND. For example, when the voltage level of a specific node ND is equal to a set level, it indicates that the connection between the daughter board 102 and the connector 120A is normal. Therefore, the operating circuit 113 enters a normal mode. In normal mode, the operating circuit 113 operates based on signals from the daughter board 102. At this time, signals from the daughter board 102 may affect the operation of the control circuit 111, such as affecting the output of the control circuit 111.

[0047] However, when the voltage level of a specific node ND is not equal to a set level, it indicates an abnormal connection between the daughterboard 102 and the connector 120A, such as the daughterboard 102 falling off without warning or the connector 120A malfunctioning. Therefore, the operating circuit 113 enters a safety mode. In safety mode, the operating circuit 113 performs a safety action to prevent abnormal operation of the control system 100A.

[0048] For example, suppose the control system 100A is an autonomous vehicle system. In this example, if the sub-board 102 detaches without warning or the connector 120A malfunctions, the control circuit 111 and the operating circuit 113 cannot receive signals from the sub-board 102, nor can they transmit control signals to the sub-board 102. Therefore, the operating circuit 113 requests the control system 100A to enter an emergency state. In the emergency state, the control system 100A may reduce the vehicle speed, issue a warning sound, or display a warning image to notify the driver of the abnormal event. In another embodiment, the operating circuit 113 may request the control circuit 111 to stop using signals from the connector 120A.

[0049] In one possible embodiment, the operating circuit 113 includes a power supply circuit 115. The power supply circuit 115 operates in either a normal mode or a safety mode based on the voltage level of a specific node ND. For example, when the connection between daughterboard 102 and connector 120A is normal, the voltage level of the specific node ND is equal to a set level. Therefore, the power supply circuit 115 enters a normal mode. In normal mode, the power supply circuit 115 provides a power supply VBA to connector 120A. In one possible embodiment, the power supply circuit 115 receives an input voltage VIN and uses the input voltage VIN as the power supply VBA. When the connection between daughterboard 102 and connector 120A is abnormal or connector 120A fails, the voltage level of the specific node ND is not equal to a set level. Therefore, the power supply circuit 115 enters a safety mode. In safety mode, the power supply circuit 115 stops providing power supply VBA to connector 120A.

[0050] In some embodiments, when an abnormal condition occurs, the power supply circuit 115 suspends the supply of power VBA. For example, when the input voltage VIN exceeds an upper limit or falls below a lower limit, or when a specific current exceeds a preset range, the power supply circuit 115 suspends the supply of power VBA.

[0051] In other embodiments, the operating circuit 113 includes a microcontroller (MCU) 114. The microcontroller 114 operates in a normal mode or a safety mode based on the voltage level of a specific node ND. For example, when the voltage level of the specific node ND is equal to a set level, the microcontroller 114 enters a normal mode. In normal mode, the microcontroller 114 may use signals from the daughterboard 102 or output signals to the daughterboard 102. When the voltage level of the specific node ND is not equal to a set level, it indicates an abnormal connection between the daughterboard 102 and the connector 120A or a fault in the connector 120A. Therefore, the microcontroller 114 enters a safety mode. In safety mode, the microcontroller 114 may request the control system 100A to enter an emergency state. In an emergency state, the control system 100A may reduce vehicle speed, issue warning messages, or stop using signals from the daughterboard 102. In other embodiments, the control system 100A has other devices for controlling vehicle speed and presenting warning messages.

[0052] Figure 1B This is a schematic diagram of the control system of the present invention. Figure 1B The control system 100B is similar to Figure 1A The control system 100A is different in that... Figure 1B The connector 120B also includes a contact terminal D3. Contact terminal D3 is electrically connected to any one of the transmission terminals P2 to PN-1. In this embodiment, the detection circuit 112B determines whether the daughter board 102 and the connector 120B are functioning correctly based on the voltage level of contact terminal D3. For example, if the voltage of contact terminal D3 is not within a preset range, or if the detected voltage level of contact terminal D3 is not equal to a second preset level, it indicates that the daughter board 102 or the connector 120B is malfunctioning. Therefore, the detection circuit 112B sets the voltage level of a specific node ND to be different from a set level, causing the operation circuit 113 to enter a safe mode. However, when the voltage of contact terminal D3 is within a preset range, or when the voltage level of contact terminal D3 is equal to a second preset level, it indicates that the daughter board 102 or the connector 120B is functioning normally. Therefore, the detection circuit 112B does not change the voltage level of the specific node ND.

[0053] In this embodiment, the detection circuit 112B further includes transistors Q3 and Q4 and a resistor R3. Transistor Q3 is of the same type as transistors Q1 and Q2, but different from transistor Q4. In one possible embodiment, transistor Q4 is a bijunction transistor (BJT), and transistors Q1 to Q3 are metal-oxide-semiconductor (MOS) transistors, but this is not intended to limit the invention. In other embodiments, transistors Q1 to Q4 can be replaced with other electronic devices. For example, transistor Q4 may be replaced with a comparator to determine whether the voltage level at contact D3 is equal to a second preset level.

[0054] As shown in the figure, the gate of transistor Q3 is coupled to resistor R3 and the collector of transistor Q4. The drain of transistor Q3 is coupled to a specific node ND, and its source receives the operating voltage VSS. The base of transistor Q4 is coupled to contact D3, its collector is coupled to the gate of transistor Q3, and its emitter receives the operating voltage VSS. Resistor R3 receives the operating voltage VCC.

[0055] When the voltage level at contact D3 is normal, such as within a specific range (e.g., 12V to 0.6V), transistor Q4 is turned on. Therefore, transistor Q3 is not turned on. At this time, if neither transistors Q1 nor Q2 are turned on, the control circuit 111 controls the voltage level of a specific node ND. However, when the voltage level at contact D3 is abnormal, such as within an abnormal range (e.g., 0 to 0.6V), transistor Q4 is not turned on. Since resistor R3 receives the operating voltage VCC, transistor Q3 is turned on. Therefore, the voltage level of a specific node ND is not equal to a set voltage. At this time, the voltage level of a specific node ND may be equal to the operating voltage VSS.

[0056] This invention does not limit the number of connectors on the motherboard 101B. In other embodiments, the motherboard 101B has more connectors for connecting more daughter boards. When different daughter boards are inserted into the connectors of the motherboard 101B, the motherboard 101B can operate according to signals provided by the daughter boards and can also control the operation of the daughter boards, thus achieving expandable and replaceable functionality. In this example, the motherboard 101B has more detection circuits. Each detection circuit detects a corresponding connector to check whether the connection between the daughter board and the connector is normal and whether the connector is faulty.

[0057] Furthermore, the present invention does not limit the number of contact terminals. In other embodiments, the detection circuit 112B may detect the voltage levels of more contact terminals to determine whether the corresponding connector and daughterboard are functioning properly. When a connector fails or a daughterboard detaches, the control system 100B enters an emergency state to prevent accidents and significantly improve safety.

[0058] Figure 2This is a schematic diagram illustrating the operation of the safety mechanism circuit of the present invention. For ease of explanation, it is shown below. Figure 1A Taking control system 100A as an example, suppose control system 100A is applied in an autonomous vehicle. During operation 210, the autonomous vehicle is running. However, due to vibrations during driving, or poor assembly between sub-board 102 and connector 120A, sub-board 102 may become detached or partially detached, preventing proper connection of connector 120A. In addition, due to manufacturing or design defects, insufficient solder on connector 120A may occur, resulting in solder cracks, causing connector 120A to fail to properly transmit signals from main board 101A to sub-board 102, or to abnormally transmit signals from sub-board 102 to main board 101A. Therefore, during operation 210, connector 120A may malfunction or sub-board 102 may become detached.

[0059] When connector 120A fails or daughterboard 102 becomes detached, the voltage level at contact point D1 is not equal to a preset level. Since detection circuit 112A continuously detects the voltage level at contact point D1, during a diagnostic period 220, once detection circuit 112A detects that the voltage level at contact point D1 is not equal to a preset level, it immediately sets the voltage level of a specific node ND, so that the voltage level of the specific node ND is not equal to a set level.

[0060] During a reaction period 230, the operating circuit 113, based on the voltage level of a specific node ND, determines that connector 120A is unable to properly transmit signals from daughterboard 102, indicating that daughterboard 102 may have detached or connector 120A may be faulty. Therefore, at time point T4, the operating circuit 113 performs a safety action, such as reducing vehicle speed and notifying the driver. Upon receiving the notification, the driver may immediately seek a suitable parking spot.

[0061] At time T5, the driver stops the vehicle, bringing it to a safe state. In this safe state, the driver notifies a repair shop to reinstall sub-board 102, ensuring it correctly connects to connector 120A. When detection circuit 112A detects a normal connection between sub-board 102 and connector 120A by checking the voltage level at contact point D1, detection circuit 112A stops allowing the voltage level of specific node ND to deviate from a set level. At this point, control circuit 111 may set the voltage level of specific node ND to a set level. Therefore, operating circuit 113 enters a normal mode and notifies the driver that all vehicle functions are normal.

[0062] Because the detection circuit 112A continuously monitors the voltage level of contact terminal D1, when the voltage level of contact terminal D1 is abnormal, the detection circuit 112A immediately sets the voltage level of a specific node ND. Therefore, the operation circuit 113 can perform safety actions in real time, greatly improving the safety of the control system 100A and avoiding accidents such as collisions or loss of control of the self-driving vehicle.

[0063] Unless otherwise defined, all terms herein (including technical and scientific terms) are as commonly understood by one of ordinary skill in the art to which this invention pertains. Furthermore, unless expressly stated otherwise, definitions of terms in general dictionaries should be interpreted as consistent with their meaning in the context of their respective technical fields, and not as idealized or overly formal expressions. While terms such as “first” and “second” may be used to describe various elements, these elements should not be limited by these terms. These terms are merely used to distinguish one element from another. In the claims, terms such as “first” and “second” are used as designations and are not intended to impose numerical requirements on their contents.

[0064] While the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the invention. Those skilled in the art can make modifications and refinements without departing from the spirit and scope of the invention. For example, the systems, apparatus, or methods described in the embodiments of the present invention can be implemented in physical embodiments using hardware, software, or a combination of hardware and software. Therefore, the scope of protection of the present invention should be determined by the scope defined in the appended claims.

Claims

1. A safety mechanism circuit disposed in a host board, the host board comprising a connector for connecting a functional module, the safety mechanism circuit comprising: a detection circuit coupled between a first contact of the connector and a specific node; a control circuit for setting a voltage level of the specific node to a set level when the functional module is connected to the connector and a specific function is enabled; and an operation circuit for operating in a normal mode or a safety mode according to the voltage level of the specific node, wherein: when the functional module is connected to the connector: the functional module is electrically connected to the first contact, the detection circuit detects a voltage level of the first contact, when the voltage level of the first contact is not equal to a first preset level, the detection circuit sets the voltage level of the specific node to be not the set level, and the operation circuit enters the safety mode, in which the operation circuit performs a safety action, when the voltage level of the first contact is equal to the first preset level, the operation circuit enters the normal mode, in which the operation circuit does not perform the safety action.

2. The safety mechanism circuit of claim 1, wherein the operation circuit comprises: a power supply circuit for providing a power supply to the connector in the normal mode and stopping providing the power supply to the connector in the safety mode.

3. The safety mechanism circuit of claim 2, wherein the operation circuit further comprises: a microcontroller for issuing a warning message in the safety mode and stopping issuing the warning message in the normal mode.

4. The safety mechanism circuit of claim 3, wherein the microcontroller employs an output signal of the functional module in the normal mode and stops employing the output signal of the functional module in the safety mode.

5. The safety mechanism circuit of claim 1, wherein the detection circuit comprises: a first resistor receiving a first operating voltage; and a first transistor comprising a first gate, a first drain and a first source, the first gate being coupled to the first contact and the first resistor, the first drain being coupled to the specific node, and the first source receiving a second operating voltage, wherein the first operating voltage is greater than the second operating voltage.

6. The safety mechanism circuit of claim 5, wherein: when the functional module is connected to the connector: the functional module is electrically connected to a second contact of the connector, the detection circuit detects a voltage level of the second contact, when the voltage level of the second contact is not equal to the first preset level, the detection circuit sets the voltage level of the specific node to be not the set level.

7. The safety mechanism circuit of claim 6, wherein the detection circuit further comprises: a second resistor receiving the first operating voltage; and a second transistor comprising a second gate, a second drain and a third source, the second gate being coupled to the second contact and the second resistor, the second drain being coupled to the specific node, and the second source receiving the second operating voltage.

8. The safety mechanism circuit of claim 7, wherein when the functional module is connected to the connector: the functional module is electrically connected to a third contact of the connector, ​ ​ ​ The detection circuit detects a voltage level of the third contact terminal, when the voltage level of the third contact terminal is not equal to a second preset level, the detection circuit sets the voltage level of the specific node not to be the set level, the second preset level is greater than the first preset level.

9. The security mechanism circuit of claim 8, wherein the detection circuit further comprises: a third resistor receiving the first operating voltage; a third transistor comprising a third gate, a third drain, and a third source, the third gate coupled to the third resistor, the third drain coupled to the specific node, and the third source receiving the second operating voltage; and a fourth transistor comprising a base, a collector, and an emitter, the base coupled to the third contact, the collector coupled to the third gate, and the emitter receiving the second operating voltage.

10. A host board, comprising: a connector to couple a function module, and comprising: a first transmission terminal electrically connecting the function module and a first contact terminal; a second transmission terminal electrically connecting the function module and a second contact terminal; and a plurality of third transmission terminals between the first and second transmission terminals; and a security mechanism circuit to determine whether a connection state between the function module and the connector is abnormal, and comprising: a detection circuit coupled to the first contact terminal, the second contact terminal, and a specific node; a control circuit to set a voltage level of the specific node to be a set level when the function module is connected to the connector and a specific function is enabled; an operation circuit to operate in a normal mode or a security mode according to the voltage level of the specific node, wherein: when the function module is connected to the connector: the function module is electrically connected to the first and second contact terminals, the detection circuit detects voltage levels of the first and second contact terminals, when the voltage level of the first or second contact terminal is not equal to a first preset level, the connection state is abnormal, and the detection circuit sets the voltage level of the specific node not to be the set level, when the voltage levels of the first and second contact terminals are equal to the first preset level, the connection state is normal, when the connection state is abnormal, the operation circuit performs a security action, when the connection state is normal, the operation circuit does not perform the security action. ​

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