A micro-electromechanical sensor device testing apparatus

Abstract

This invention provides a microelectromechanical device (MEMS) sensor testing device, comprising a testing device body, which includes: a sample placement area for placing N MEMS sensors; a communication switching unit including a first input terminal, a second input terminal, a third input terminal, a first output terminal, a second output terminal, a third output terminal, and a controlled terminal; the first input terminal is electrically connected to the SDI terminal of the MEMS sensor; the second input terminal is electrically connected to the CS terminal of the MEMS sensor; the third input terminal is electrically connected to the SDO terminal of the MEMS sensor; and an SPI interface, whose SCK clock input terminal is electrically connected to the SCK terminal of the MEMS sensor, and whose slave signal input terminal, chip select terminal, and slave signal output terminal are electrically connected to the first output terminal, the second output terminal, and the third output terminal, respectively. Compared with the prior art, this invention can be compatible with testing of SPI three-wire and four-wire communication functions with only a four-wire SPI master control device.

Description

[Technical Field]

[0001] This invention belongs to the field of sensor testing technology, and specifically relates to a testing device for microelectromechanical sensors. [Background Technology]

[0002] Microelectromechanical devices (MEMS) are high-tech electromechanical devices with a micro-electro-mechanical system (MEMS) and a size of only a few millimeters or even smaller. Their fabrication processes integrate photolithography, etching, thin film processing, LIGA, silicon micromachining, non-silicon micromachining, and precision machining technologies. Currently, MEMS-based sensors have a wide range of applications, with common products including MEMS accelerometers, MEMS gyroscopes, MEMS humidity sensors, MEMS magnetic sensors, and MEMS optical image stabilization devices.

[0003] With the increasing intelligence and speed of end-user applications, MEMS sensors are typically designed to support multiple communication methods to meet the diverse communication needs of clients. Among the many supported communication methods, SPI (Serial Peripheral Interface) is a high-speed, full-duplex, synchronous communication bus. A common four-wire SPI uses only four pins on the chip to achieve point-to-point, point-to-many, and many-to-point full-duplex communication modes. For the master device, these four pins are clock (SCK), chip select (CS), slave input signal (MOSI), and slave output signal (MISO). Simultaneously, a three-wire SPI communication mode also exists. For the slave device, three-wire SPI only requires clock (SCK), chip select (CS), and bidirectional data transceiver (SDI / O) pins. Compared to four-wire SPI, three-wire SPI has lower hardware costs, occupies fewer I / O ports, and only requires one master / slave device to achieve full-duplex communication. It is favored by many end-user applications, and an increasing number of products need to support both four-wire and three-wire SPI communication to meet the application needs of different clients. Therefore, in order to fully support SPI communication, when conducting product functional testing of microelectromechanical sensor devices, it is necessary to verify both the 4-wire SPI communication function and the reliability verification of the 3-wire SPI communication function, which poses a challenge to research and development testing.

[0004] Therefore, it is necessary to propose a new technical solution to address the above problems. [Summary of the Invention]

[0005] One of the objectives of this invention is to provide a microelectromechanical sensor device testing apparatus that can be compatible with testing the SPI three-wire and four-wire communication functions of MEMS sensors under the condition of having only an external four-wire SPI master device.

[0006] According to one aspect of the present invention, a microelectromechanical device (MEMS) sensor testing apparatus is provided, comprising a testing apparatus body, the testing apparatus body including: a sample placement area for placing N MEMS sensors, wherein N is a positive integer, each of the N MEMS sensors being provided with a four-wire SPI signal terminal, the four-wire SPI signal terminal including an SCK terminal, an SDI terminal, a CS terminal, and an SDO terminal; and a communication switching unit including a first input terminal, a second input terminal, a third input terminal, a first output terminal, a second output terminal, a third output terminal, and a controlled terminal, the first input terminal being connected to the N MEMS sensors. The first input terminal is electrically connected to the SDI terminal; the second input terminal is electrically connected to the CS terminal of the microelectromechanical sensor under test among the N microelectromechanical sensors; the third input terminal is electrically connected to the SDO terminal of the N microelectromechanical sensors; the SPI interface includes an SCK clock input terminal, a slave signal input terminal, a chip select terminal, and a slave signal output terminal, wherein the SCK clock input terminal is electrically connected to the SCK terminal of the N microelectromechanical sensors 112; the slave signal input terminal is electrically connected to the first output terminal, the chip select terminal is electrically connected to the second output terminal, and the slave signal output terminal is electrically connected to the third output terminal.

[0007] Compared with the prior art, the test device body of the microelectromechanical sensor device test apparatus provided by the present invention has a simple structure and low cost. Under the condition that no additional dedicated three-wire SPI master controller is purchased during the research and development testing stage, it can also rely on the existing four-wire SPI master controller to be used in conjunction with the test device body to realize the verification of the three-wire and four-wire SPI functions of the microelectromechanical sensor under test. This saves a lot of equipment procurement costs, improves testing efficiency, and avoids the problem of extended product testing cycle caused by the shortage of testing equipment. [Attached Image Description]

[0008] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. Wherein:

[0009] Figure 1 This is a circuit diagram of the test device body in the first embodiment of the present invention;

[0010] Figure 2 This is a schematic diagram of the read / write operation timing of four-wire SPI communication in one embodiment of the present invention;

[0011] Figure 3This is a schematic diagram of the write operation timing of three-wire SPI communication in one embodiment of the present invention;

[0012] Figure 4 This is a timing diagram of a read operation in three-wire SPI communication according to one embodiment of the present invention;

[0013] Figure 5 This is a circuit diagram of the test device body in the second embodiment of the present invention;

[0014] Figure 6 This is a circuit diagram of the test device body in the third embodiment of the present invention;

[0015] Figure 7 This is a schematic diagram of the structure of the sample placement area 11 in one embodiment of the present invention;

[0016] Figure 8 This is a circuit diagram of the test device body in the fourth embodiment of the present invention;

[0017] Figure 9 This is a schematic diagram of the structure of a four-wire SPI master controller in one embodiment of the present invention;

[0018] Figure 10 This is a schematic diagram of the structure of the I2C / I3C communication master controller in one embodiment of the present invention.

Detailed Implementation Methods

[0019] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0020] The term "an embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the invention. The phrase "in one embodiment" appearing in different places throughout this specification does not necessarily refer to the same embodiment, nor is it a single or selective embodiment that excludes other embodiments. Unless otherwise specified, the terms coupling, connection, linking, and interconnection used herein to indicate electrical connection mean direct or indirect connection. For example, A being connected to B includes both a direct electrical connection between A and B and a connection between A and B via electrical components or circuits.

[0021] In the description of this invention, it should be understood that the terms "upper", "lower", "front", "rear", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", and "outer" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0022] The microelectromechanical sensor device testing apparatus provided by this invention includes a testing apparatus body. Please refer to... Figure 1 As shown, it is a circuit diagram of the test device body in the first embodiment of the present invention. Figure 1 The test device body 1 shown includes a sample placement area 11, a communication switching unit 12, and an SPI interface 13.

[0023] The sample placement area 11 is used to place N microelectromechanical sensors 112, where N is a positive integer. Each of the N microelectromechanical sensors 112 is provided with a four-wire SPI signal terminal 111, which includes an SCK terminal 1111, an SDI terminal 1112, a CS terminal 1113, and an SDO terminal 1114.

[0024] The communication switching unit 12 is used to switch the SPI communication signal. The communication switching unit 12 includes a first input terminal 121, a second input terminal 122, a third input terminal 123, a first output terminal 124, a second output terminal 125, a third output terminal 126, and a controlled terminal 127. The first input terminal 121 is electrically connected to the SDI terminal 1112 of the four-wire SPI signal terminals 111 of the N microelectromechanical sensors 112; the third input terminal 123 is electrically connected to the SDO terminal 1114 of the four-wire SPI signal terminals 111 of the N microelectromechanical sensors 112; and the second input terminal 122 is electrically connected to the CS terminal 1113 of the four-wire SPI signal terminals 111 of the microelectromechanical sensor 112 under test. Figure 1 In the specific embodiment shown, the microelectromechanical sensor device under test 112 is microelectromechanical sensor device 3, and the second input terminal 122 of the communication switching unit 12 is electrically connected to the CS terminal 1113 of the four-wire SPI signal terminal 111 of microelectromechanical sensor device 3. When microelectromechanical sensor device 1, microelectromechanical sensor device 2, or microelectromechanical sensor device N is used as the microelectromechanical sensor device under test, it is necessary to electrically connect the CS terminal 1113 of the four-wire SPI signal terminal 111 of microelectromechanical sensor device 1, microelectromechanical sensor device 2, or microelectromechanical sensor device N to the second input terminal 122.

[0025] SPI interface 13 is used to connect to an external four-wire SPI master controller 2 (see details). Figure 9 (As shown). The SPI interface 13 includes an SCK clock input terminal 131, a slave signal input terminal 132, a chip select terminal 133, and a slave signal output terminal 134. The SCK clock input terminal 131 is electrically connected to the SCK terminal 1111 of the four-wire SPI signal terminals 111 of the N microelectromechanical sensors 112. The slave signal input terminal 132 is electrically connected to the first output terminal 124 of the communication switching unit 12. The chip select terminal 133 is electrically connected to the second output terminal 125 of the communication switching unit 12. The slave signal output terminal 134 is electrically connected to the third output terminal 126 of the communication switching unit 12.

[0026] The communication switching unit 12 is controlled to switch between a first output state and a second output state. Specifically, the first input terminal 121 is connected to the first output terminal 124, the second input terminal 122 is connected to the second output terminal 125, and the third input terminal 123 is connected to the third output terminal 126, constituting the first output state; the first input terminal 121 is disconnected from the first output terminal 124 and connected to the third output terminal 126, the second input terminal 122 is disconnected from the second output terminal 125 and grounded, and the third input terminal 123 is disconnected from the third output terminal 126 and configured as a high-Z (high impedance) state, constituting the second output state.

[0027] In use, the microelectromechanical sensor 112 is placed in the sample placement area 11 to achieve electrical connection between the microelectromechanical sensor 112 and the communication switching unit 12. Specifically, the SCK clock input terminal 131, slave signal input terminal 132, chip select terminal 133, and slave signal output terminal 134 of the SPI interface 13 of the test device body 1 can be connected to an external four-wire SPI master controller 2 via DuPont wires or other communication cables. For details, please refer to [link to relevant documentation]. Figure 9 As shown, it is a schematic diagram of the structure of a four-wire SPI master controller in one embodiment of the present invention. Figure 9The four-wire SPI master controller 2 shown includes an SCK pin 21, a MOSI pin 22, a CS pin 23, and a MISO pin 24. The SCK clock input terminal 131 of the SPI interface 13 is connected to the SCK pin 21 of the four-wire SPI master controller 2; the slave signal input terminal 132 of the SPI interface 13 is connected to the MOSI pin 22 of the four-wire SPI master controller 2; the chip select terminal 133 of the SPI interface 13 is connected to the CS pin 23 of the four-wire SPI master controller 2; and the slave signal output terminal 134 of the SPI interface 13 is connected to the MISO pin 24 of the four-wire SPI master controller 2. In other words, the microelectromechanical sensor device testing device provided by the present invention also includes a four-wire SPI master controller 2. The four-wire SPI master controller 2 includes an SCK pin 21, a MOSI pin 22, a CS pin 23, and a MISO pin 24. The SCK clock input terminal 131 of the SPI interface 13 is connected to the SCK pin 21 of the four-wire SPI master controller 2; the slave device signal input terminal 132 of the SPI interface 13 is connected to the MOSI pin 22 of the four-wire SPI master controller 2; the chip select terminal 133 of the SPI interface 13 is connected to the CS pin 23 of the four-wire SPI master controller 2; and the slave device signal output terminal 134 of the SPI interface 13 is connected to the MISO pin 24 of the four-wire SPI master controller 2.

[0028] When testing the four-wire SPI communication function of the microelectromechanical sensor 112, the communication switching unit 12 is controlled or defaults to the first output state, that is, maintaining the four-wire SPI signal output of the microelectromechanical sensor 112. At this time, the four-wire SPI master controller 2 acts as the master device, and the microelectromechanical sensor 112 acts as the slave device, forming a microelectromechanical sensor test system for testing the four-wire SPI communication function. For the timing principle of the four-wire SPI communication read and write operations, please refer to [reference needed]. Figure 2 As shown, Figure 2 This is a schematic diagram illustrating the read / write timing of a four-wire SPI communication operation in one embodiment of the present invention. Those skilled in the art can use the microelectromechanical sensor device testing apparatus (such as...) provided by the present invention... Figure 1 and Figure 9 (As shown) combined Figure 2 The implementation principle is understood, so I won't go into details.

[0029] It is worth noting that when testing the three-wire SPI communication function of the microelectromechanical sensor 112, refer to... Figure 1 and Figure 3 To understand, Figure 3This is a schematic diagram of the write operation timing of three-wire SPI communication in one embodiment of the present invention. The controlled terminal 127 of the communication switching unit 12 is controlled to maintain the first output state. First, using the current four-wire SPI communication mode, the four-wire SPI master controller 2 controls its CS pin 23 to pull the level of the CS terminal 1113 of the microelectromechanical sensor 112 connected to it through the SPI interface 13 and the communication switching unit 12 to pull it low. At this time, it represents the start of SPI communication. The four-wire SPI master controller 2 controls its SCK pin 21 to transmit at least 16 clock cycle signals to the microelectromechanical sensor 112 through the SPI interface 13 (see details). Figure 2 (As shown), at the same time, the four-wire SPI master controller 2 utilizes Figure 3 The write operation timing shown involves performing a register configuration write operation on the microelectromechanical device under test (MEMS) 112 (such as configuring the operating mode, CPOL clock polarity, CPHA clock phase, etc. This solution does not specifically limit the register configuration method; it is provided as a reference. The clock triggers in the attached diagram are all rising edge valid and will not be elaborated here). This configures the operating mode of the MEMS 112 under test as three-wire in the register, enabling multiplexing of transmit and receive signals at the SDI terminal 1112 of the MEMS 112. In other words, when testing the three-wire SPI communication function of the MEMS 112, the communication switching unit 12 first operates in the first output state. Using the four-wire SPI communication mode, the four-wire SPI master controller 2 performs a register configuration write operation on the MEMS 112 under test, configuring the operating mode of the MEMS 112 under test as three-wire in the register, so that multiplexing of transmit and receive signals can be achieved at the SDI terminal 1112 of the MEMS 112 under test.

[0030] When only it is necessary to verify the validity of the three-wire SPI write operation command (or to verify the three-wire SPI write operation function), the communication switching unit 12 maintains the first output state, and the four-wire SPI master controller 2 can adopt... Figure 3 The communication timing shown, within 16 clock cycles (i.e., one write operation instruction cycle), the first 8 clock cycles are mainly used to write the register address (AD5-AD0, the address occupies 6 bits in this embodiment, only as an example), and the last 8 clock cycles are used to write the operation data (DO7-DO0, 1 byte). This is the principle of single-byte SPI write operation. For multi-byte write operations, the clock block can be further extended based on the 16-clock-cycle operation timing disclosed in this scheme, which is understandable to those skilled in the art and will not be elaborated here. That is to say, when it is only necessary to verify the write operation function of the three-wire SPI, the communication switching unit 12 maintains the first output state, and the four-wire SPI master controller 2 writes the register address and operation data to the microelectromechanical sensor device under test 112.

[0031] When further verification of the read operation function of the three-wire SPI is required, refer to Figure 4 As shown, Figure 4 This is a timing diagram of a read operation in a three-wire SPI communication embodiment of the present invention. A trigger control signal is given to the controlled terminal 127 of the communication switching unit 12 after the 8th rising edge of 16 clock cycles and before the 9th rising edge (or after the read register address in the read operation instruction issued by the four-wire SPI master controller 2), causing the communication switching unit 12 to switch from the first output state to the second output state. At this time, the first input terminal 121 of the communication switching unit 12 is disconnected from the first output terminal 124, and therefore no longer receives write operation data from the four-wire SPI master controller 2. Simultaneously, the first input terminal 121 is connected to the third output terminal 126, and the SDI terminal 1112 of the microelectromechanical device under test 112 automatically returns the data (DO7-DO0) of the read register, which is then transmitted through the third output terminal 126. The MISO pin 24, which feeds back to the four-wire SPI master controller 2, allows verification of the correctness of communication data in the three-wire SPI communication mode from the master device. During this process, the second input terminal 122 and the second output terminal 125 are disconnected, and the second input terminal 122 is grounded, so that the CS terminal 1113 of the slave device (i.e., the microelectromechanical sensor device under test 112) is in a continuous low level for communication, ensuring the smooth progress of the three-wire SPI read operation. Furthermore, the third input terminal 123 is disconnected from the third output terminal 126, and the third input terminal 123 is configured in a high-Z state (high impedance state). This communication process is entirely achieved by the bidirectional data transmission and reception of the SDI terminal 1113. In the three-wire SPI communication mode, the SDO terminal 1114 no longer functions, thus better completing the "three-wire" working mode in hardware. When the three-wire SPI read operation is completed, the controlled terminal 127 of the control communication switching unit 12 switches from the second output state to the first output state. At this time, the state of the CS terminal 1113 of the microelectromechanical sensor device under test 112 is pulled high by the external four-wire SPI master controller 2, thus ending the three-wire SPI read operation communication.

[0032] In other words, when further verification of the three-wire SPI read operation function is required, after the four-wire SPI master controller 2 sends the register address to be read in the read operation command to the microelectromechanical sensor device, the communication switching unit 12 switches from the first output state to the second output state. At this time, the SDI terminal 1112 of the microelectromechanical sensor device under test 112 returns the data of the read register, which is fed back to the MISO pin 24 of the four-wire SPI master controller 2 through the third output terminal 126. When the three-wire SPI read operation is completed, the communication switching unit 12 switches from the second output state to the first output state. At this time, the state of the CS terminal 1113 of the SDI terminal 1112 of the microelectromechanical sensor device under test 112 is pulled high by the four-wire SPI master controller 2, ending the three-wire SPI read operation communication.

[0033] It should be noted that the communication switching unit 12 in the test device body 1 provided by the present invention only needs to have the aforementioned structure to realize the switching between the two states. For example, it can be MAX4996, TMUX1134, etc., and is not limited to a specific model. This is something that those skilled in the art can further select based on the content disclosed in the specification, and will not be elaborated further.

[0034] Please refer to Figure 5 As shown, it is a circuit diagram of the test device body in the second embodiment of the present invention, and... Figure 1 The difference in the main body of the test device shown is that, Figure 5 The test device body 1 shown also includes a multiplexer 14.

[0035] The multiplexer 14 includes an output channel connection terminal 145, a channel selection control terminal 146, and N input channel connection terminals (141, 142, 143, 144). The N input channel connection terminals (141, 142, 143, 144) of the multiplexer 14 are respectively connected to the CS terminals 1113 of the four-wire SPI signal terminals 111 of the N microelectromechanical sensors 112. Figure 5In the specific embodiment shown, the input channel connection terminal 141 of the multiplexer 14 is connected to the CS terminal 1113 of the four-wire SPI signal terminal 111 of the microelectromechanical sensor device 1; the input channel connection terminal 142 of the multiplexer 14 is connected to the CS terminal 1113 of the four-wire SPI signal terminal 111 of the microelectromechanical sensor device 2; the input channel connection terminal 143 of the multiplexer 14 is connected to the CS terminal 1113 of the four-wire SPI signal terminal 111 of the microelectromechanical sensor device 3; and the input channel connection terminal 144 of the multiplexer 14 is connected to the CS terminal 1113 of the four-wire SPI signal terminal 111 of the microelectromechanical sensor device N. The output channel connection terminal 145 of the multiplexer 14 is connected to the second input terminal 122 of the communication switching unit 12. The channel selection control terminal 146 is used to receive external control signals to connect any input channel connection terminal (141, 142, 143, 144) to the output channel connection terminal 145; the CS terminals 1113 of the N microelectromechanical sensors 112 are all connected to the high level state through pull-up resistors.

[0036] Figure 1 The provided testing device body can perform three-wire and four-wire SPI communication function tests on multiple microelectromechanical sensors 112 with further reasonable configuration of peripheral circuits. For example, the CS terminals 1113 of multiple microelectromechanical sensors 112 in the sample placement area 11 can be manually shorted one by one to the second input terminal 122 of the communication switching unit 12 using jumper caps to verify their corresponding three-wire or four-wire SPI communication functions. This is something that those skilled in the art can understand and implement based on the microelectromechanical sensor testing device and system structure provided by this invention.

[0037] To provide a more preferred solution, refer to Figure 5 As shown, by further configuring the multiplexer 14, under the control signal enable of the external master controller (e.g., a four-wire SPI master controller 2), the CS terminal 1113 of any microelectromechanical sensor device 112 can be selected by the multiplexer 14 according to the test requirements. Compared with the method of manually switching jumper caps, the switching of the test device (i.e., the microelectromechanical sensor device 112) depends more on the control of the electronic trigger signal, without the need for manual switching of wiring, and the test efficiency is higher.

[0038] The model and number of channels of multiplexer 14 are not specifically limited. For example, it can be a four-channel multiplexer of ADG704. Its internal channel selection control terminal 146 can decode the level input of A0 and A1 signal terminals using a 4-to-1 decoder when EN is enabled. For example, when the received signal of A1-A0 is 00, the input channel connection terminal 141 is connected to the output channel connection terminal 145. At this time, the CS terminal 1113 of the microelectromechanical sensor device 1 is connected through multiplexer 14, communication switching unit 12 and SP. Interface 13 is connected to an external four-wire SPI master controller 2. When the CS pin 23 of the external four-wire SPI master controller 2 is pulled low, the CS terminals 1113 of the other microelectromechanical sensors 2 to N are all connected to a high level through pull-up resistors. Only the CS terminal of microelectromechanical sensor 1 is pulled low by the external four-wire SPI master controller 2, indicating that the SPI communication process can be started. This avoids communication conflicts on the SPI bus and improves the reliability of microelectromechanical sensor testing using the microelectromechanical sensor testing device provided by this invention. Similarly, if it is necessary to test the 2nd, 3rd, and 4th microelectromechanical sensors, the truth tables of A0 and A1 can be configured as 01-10-11 respectively, allowing the multiplexer 14 to select the CS terminal 1113 of the corresponding microelectromechanical sensor. Furthermore, the principle of the multiplexer 14 with more channels can be further implemented based on the content disclosed in this invention, and the model of the multiplexer 14 is not limited, as long as it can be selected by external signal / level control. This is something that those skilled in the art can understand and implement in one step based on the content of this specification, and will not be elaborated further here.

[0039] Please refer to Figure 6 As shown, it is a circuit diagram of the test device body in the third embodiment of the present invention, and... Figure 5 The difference in the main body of the test device shown is that, Figure 6The test device body 1 shown also includes a bidirectional logic level converter 15 for logic level conversion. The bidirectional logic level converter 15 includes a first pull-up level input port 151, a second pull-up level input port 152, four first logic level ports (1511, 1512, 1513, 1514), and four second logic level ports (1521, 1522, 1523, 1524). The four first logic level ports (1511, 1512, 1513, 1514) and the four second logic level ports (1521, 1522, 1523, 1524) correspond one-to-one. Specifically, first logic level port 1511 corresponds to second logic level port 1521; first logic level port 1512 corresponds to second logic level port 1522; first logic level port 1513 corresponds to second logic level port 1523; and first logic level port 1514 corresponds to second logic level port 1524. The four first logic level ports (1511, 1512, 1513, 1514) are pulled up to the level of the first pull-up level input port 151 by default; the four second logic level ports (1521, 1522, 1523, 1524) are pulled up to the level of the second pull-up level input port 152 by default; the four first logic level ports (1511, 1512, 1513, 1514) are respectively electrically connected to the SCK terminals 11 of N microelectromechanical sensors 112. 11. The SDI terminal 1112 of N microelectromechanical sensors 112, the output channel connection terminal 145 of the multiplexer 14, and the SDO terminal 1114 of the N microelectromechanical sensors 112; four second logic level ports (1521, 1522, 1523, 1524) are electrically connected to the SCK clock input terminal 131 of the SPI interface 13, and the first input terminal 121, the second input terminal 122, and the third input terminal 123 of the communication switching unit 12. Specifically, the first logic level port 1511 is electrically connected to the SCK terminal (or SCL terminal) 1111 of N microelectromechanical sensors 112; the first logic level port 1512 is electrically connected to the SDI terminal (or SDA terminal) 1112 of N microelectromechanical sensors 112; the first logic level port 1513 is electrically connected to the output channel connection terminal 145 of the multiplexer 14; and the first logic level port 1514 is electrically connected to the SDO terminal 1114 of N microelectromechanical sensors 112. The second logic level port 1521 is electrically connected to the SCK clock input terminal 131 of the SPI interface 13; the second logic level port 1522 is electrically connected to the first input terminal 121 of the communication switching unit 12; the second logic level port 1523 is electrically connected to the second input terminal 122 of the communication switching unit 12; and the second logic level port 1524 is electrically connected to the third input terminal 123 of the communication switching unit 12.

[0040] The present invention provides the use of Figure 6 The microelectromechanical sensor device testing device shown in the diagram can be implemented using an external DC power supply, or by setting a reference power output terminal on the testing device body 1 to provide the slave device's IO reference voltage (or reference level) to the first pull-up level input port 151 of the testing device body 1; the external communication master controller (reference) can also provide the reference voltage. Figure 8-9 The VDDIO port of the main unit 1 supplies the IO reference voltage (or reference level) from the main control device to the second pull-up level input port 152 of the test device body 1. When the bidirectional logic level converter 15 is working, it will pull up the four first logic level ports (1511, 1512, 1513, 1514) to the level of their first pull-up level input port 151 by default, and simultaneously pull up the four second logic level ports (1521, 1522, 1523, 1524) to the level of their second pull-up level input port 152 by default. In this way, sampling... Figure 6 The microelectromechanical sensor device test apparatus shown in the diagram can further address the issue of external communication controllers (see reference). Figure 8-9 The VDDIO of the microelectromechanical sensor 112 only provides a few fixed reference levels (e.g., 3.6V, 1.8V), resulting in a limitation that the IO level of the microelectromechanical sensor 112 cannot be verified for communication reliability over a wide voltage range. A bidirectional logic level converter 15, whose selection is not limited to a specific model or form (e.g., ADG3304), converts the level of a signal from one logic OR voltage level to another. When the reference level input to the second pull-up level input port 152 is 3.6V, the first pull-up level input port 151 can support a wide range of input levels from 1.08V to 3.6V, thereby achieving signal compatibility and interconnection between different circuits. This allows master and slave devices to communicate and interact even when they support different levels. In this way, the IO drive capability of the microelectromechanical sensor 112 can be tested more comprehensively over a wide voltage range.

[0041] Please refer to Figure 7 As shown, this is a schematic diagram of the structure of the sample placement area 11 in one embodiment of the present invention. Figure 7 In the embodiment shown, the N (or more) microelectromechanical sensor devices 112 placed in the sample placement area 11 include microelectromechanical gyroscope devices and / or microelectromechanical accelerometers and / or microelectromagnetic sensors and / or microelectromechanical optical image stabilizers.

[0042] Preferably, multiple types of products, such as microelectromechanical gyroscopes, microelectromechanical accelerometers, microelectromagnetic sensors, and microelectromechanical optical image stabilizers, are simultaneously placed in the sample placement area 11. This involves electrically connecting the microelectromechanical sensor 112 to the sample placement area 11, and extracting the signals from the SCK terminal 1111, SDI terminal 1112, CS terminal 1113, and SDO terminal 1114 of the microelectromechanical sensor 112. This approach is not limited to any specific implementation method.

[0043] As a preferred option, the microelectromechanical sensor 112 can be placed in the sample placement area 11 by setting a test socket, which facilitates the replacement of the microelectromechanical sensor 112. That is, a test socket is set in the sample placement area 11, and the four-wire SPI signal terminal of the microelectromechanical sensor 112 is plugged into the corresponding test socket.

[0044] As another preferred option, if PCB package pads for microelectromechanical gyroscopes, microelectromechanical accelerometers, microelectromagnetic sensors, and microelectromechanical optical image stabilizers (i.e., microelectromechanical sensor devices 112) are reserved in the sample placement area 11, then the microelectromechanical sensor devices 112 can be electrically connected to the sample placement area 11 by SMT soldering. In other words, the sample placement area 11 has reserved PCB package pads for the microelectromechanical sensor devices 112, and the four-wire SPI signal terminals of the microelectromechanical sensor devices 112 are soldered to the corresponding PCB package pads. This implementation method ensures the reliability of the connection between the microelectromechanical sensor 112 and the sample placement area 11, making the external electrical signal output of the microelectromechanical sensor 112 relatively stable. At the same time, it is directly soldered to the PCB package pad by surface mount technology, which minimizes the trace distance and avoids the introduction of additional impedance and capacitive reactance. The applicant has found in multiple practices that this method has better anti-interference performance, avoids unnecessary resistance and capacitance from interfering with the test device, and can improve the upper limit of the test speed for reliable SPI communication testing.

[0045] The microelectromechanical device (MEMS) sensor testing device provided by this invention, by simultaneously placing different MEMS sensors 112 in the sample placement area 11, allows the use of a single testing device, compatible with communication verification of different types of MEMS sensors. This shortens the product development and testing cycle and facilitates the identification of design differences between different MEMS sensors, such as differences in internal chip driving capabilities. Furthermore, it eliminates the need for a separate testing device for each product, which is crucial for problem localization and high / low temperature characteristic testing during the development phase. Different types of products can be tested simultaneously at the same temperature, eliminating the need for frequent removal of the testing device from the high / low temperature oven to replace the circuit under test. This maintains consistency in testing conditions, eliminates interference from different testing environments, facilitates diagnosis of testing differences, significantly improves testing efficiency, and shortens the design cycle.

[0046] Please refer to Figure 8 As shown, it is a circuit diagram of the test device body in the fourth embodiment of the present invention, and... Figure 6 The difference in the main body of the test device shown is that, Figure 8 The test device body 1 shown also includes a two-wire switch 17 and an I2C / I3C communication interface 16 for connecting an external I2C / I3C communication master controller.

[0047] The I2C / I3C communication interface 16 includes an SCL clock signal terminal 161 and an SDA digital signal terminal 162. The SCL clock signal terminal 161 is electrically connected to a second logic level port 1521 for switching the level of the SCK terminal 1111 via a two-wire switch 17. The SDA digital signal terminal 162 is electrically connected to a second logic level port 1522 for switching the level of the SDI terminal 1112 via a two-wire switch 17. The two-wire switch 17 has two states: closed (or connected) and open. When the two-wire switch 17 is closed (or connected), the second logic level port 1521 used to switch the SCK terminal 1111 level is connected to the SCL clock signal terminal 161, and the second logic level port 1522 used to switch the SDI terminal 1112 level is connected to the SDA digital signal terminal 162; when the two-wire switch 17 is open, the connection between the second logic level port 1521 used to switch the SCK terminal 1111 level and the SCL clock signal terminal 161 is disconnected, and the connection between the second logic level port 1522 used to switch the SDI terminal 1112 level and the SDA digital signal terminal 162 is also disconnected.

[0048] exist Figure 8The test device body 1 shown is equipped with an I2C / I3C communication interface 16. The SCL pin 31 and SDA pin 32 of an external I2C / I3C communication master controller 3 can be electrically connected via DuPont wires (or other cables) to the SCL clock signal terminal 161 and SDA digital signal terminal 162 of the I2C / I3C communication interface 16 of the test device body 1. Please refer to [link / reference] for details. Figure 10 As shown, this is a schematic diagram of the structure of the I2C / I3C communication master controller in one embodiment of the present invention. Figure 10 The I2C / I3C communication master controller 3 shown includes an SCL pin 31 and an SDA pin 32. The SCL pin 31 of the I2C / I3C communication master controller 3 is electrically connected to the SCL clock signal terminal 161 of the I2C / I3C communication interface 16; the SDA pin 32 of the I2C / I3C communication master controller 3 is electrically connected to the SDA digital signal terminal 162 of the I2C / I3C communication interface 16. In other words, the microelectromechanical sensor device testing device provided by the present invention also includes an I2C / I3C communication master controller 3. The I2C / I3C communication master controller 3 includes an SCL pin 31 and an SDA pin 32. The SCL pin 31 of the I2C / I3C communication master controller 3 is electrically connected to the SCL clock signal terminal 161 of the I2C / I3C communication interface 16; the SDA pin 32 of the I2C / I3C communication master controller 3 is electrically connected to the SDA digital signal terminal 162 of the I2C / I3C communication interface 16. At this time, the two-wire switch 17 can be closed (or connected) by manually turning on the jumper cap or by enabling it with an external signal. Closing the two-wire switch 17 means connecting the second logic level port 1521, which is used to convert the level of the SCK terminal 1111, to the SCL clock signal terminal 161 of the I2C / I3C communication interface 16, and connecting the second logic level port 1522, which is used to convert the level of the SDI terminal 1112, to the SDA digital signal terminal 162 of the I2C / I3C communication interface 16. This allows the second logic level ports 1521 and 1522 to convert the levels of the SCK terminal 1111 and the SDI terminal 1112 and then bring them out to the I2C / I3C communication interface 16. In use, the external I2C / I3C communication master controller 3 (refer to...) Figure 10The I2C bus communication is initiated. A serial clock signal for I2C / I3C communication verification is generated from the SCL pin 31 of the external I2C / I3C communication master controller 3. A serial data signal for I2C / I3C communication verification is transmitted from the SDA pin 32 of the external I2C / I3C communication master controller 3 to the SDA digital signal terminal 162 of the test device body 1. Each microelectromechanical sensor 112 connected to the bus can be configured with an independent device address. The host can use this address to perform read and write operations between different devices. The I2C communication test result of the microelectromechanical sensor 112 is judged based on the return value of the slave device. Similarly, I3C communication is backward compatible with the I2C communication protocol. It also utilizes the SCL and SDA signal lines. Based on the control of the I3C master controller, it can transmit the CCC general command set and perform SDR and HDR read / write operations to the microelectromechanical sensor 112 on this test device. The return value from the microelectromechanical sensor 112 can be used to further determine the reliability of the test results. Specifically, the I2C and I3C communication protocols are common knowledge in the industry and are now relatively mature, easily understood and known to those skilled in the art; therefore, they will not be elaborated upon further here.

[0049] Thus, this invention, in its microelectromechanical sensor testing device structure, eliminates the need for purchasing an expensive three-wire SPI master controller. It enables comprehensive verification of multiple communication functions using a simple testing device body 1. It can be used not only for testing SPI three-wire and four-wire communication functions but also for testing I2C and I3C communication functions with different I / O levels. This low-cost device structure achieves testing of multiple types and communication methods of microelectromechanical sensors. The entire testing device is integrated on a single PCB circuit board, resulting in a simple structure, low cost, and reliable test results. Multiple types of products can be integrated and placed on the same testing device body 1 for high and low temperature testing in an oven, resulting in high testing efficiency and significantly shortening the product development and testing cycle.

[0050] Preferably, the microelectromechanical sensor device testing device provided by the present invention includes, in addition to the testing device body 1, a four-wire SPI master controller 2 (e.g., Figure 9 (as shown) and / or I2C / I3C communication master controller 3 (such as Figure 10 (As shown).

[0051] Reference Figure 8 The test device shown includes a four-wire SPI master controller 2 with SCK pin 21, MISO pin 22, CS pin 23, and MOSI pin 24 for supporting SPI communication. It also includes a VDDIO port 25 for electrically connecting to the second pull-up level input port 152. See details... Figure 9As shown, the I2C / I3C communication master controller 3 includes an SCL pin 31 and an SDA pin 32, and also includes a VDDIO port 33 for electrical connection to the second pull-up level input port 152. Thus, the four-wire SPI master controller 2 and the I2C / I3C communication master controller 3, together with the test device body 1, constitute a microelectromechanical sensor test system compatible with three-wire and four-wire SPI communication and / or I2C and I3C functional testing. In this invention, the phrase "including certain pins" used for the microelectromechanical sensor test device 1, the four-wire SPI master controller 2, and the I2C / I3C communication master controller 3 does not mean that only these pins are included. Other pins (e.g., GND) are not described in detail due to space limitations; this is something that those skilled in the art can understand based on the content of this specification.

[0052] Preferably, refer to Figure 9 To understand this, the four-wire SPI master controller 2 also includes a first IO control terminal 2127, a second IO control terminal 2146, and a third IO control terminal 217. The first IO control terminal 2127 is electrically connected to the controlled terminal 127 of the communication switching unit 12; the second IO control terminal 2146 is electrically connected to the channel selection control terminal 146 of the multiplexer 14; and the third IO control terminal 217 is electrically connected to the control terminal 171 of the two-wire switching switch 17.

[0053] Figure 9The four-wire SPI master controller 2 shown includes four SPI signal lines (e.g., SCK pin 21, MISO pin 22, CS pin 23, and MOSI pin 24), as well as several IO control terminals (e.g., first IO control terminal 2127, second IO control terminal 2146, and third IO control terminal 217). In this way, by sending a high level (1) or low level (0) through the IO control terminals, the state switching enable of the controlled terminal 127 of the communication switching unit 12, the channel selection enable of the channel selection control terminal 146 of the multiplexer 14, and the opening and closing state enable of the controlled terminal 171 of the two-wire switching switch 17 can be achieved. In this way, by utilizing the IO terminals of the four-wire SPI master controller 2 itself, the addition of additional master control equipment can be reduced, which can further reduce the cost of the test device. Meanwhile, when using the microelectromechanical sensor device testing device provided by this invention for testing, the four-wire SPI master controller 2 and the I2C / I3C communication master controller 3 can be connected together to the main body 1 of the testing device, maintaining electrical connection with the SPI interface 13 and the I2C / I3C communication interface 16. When it is necessary to test the three-wire SPI and / or four-wire SPI functions, the four-wire SPI master controller 2 disconnects the two-wire switching switch 17 without manually unplugging the connecting cable between the I2C / I3C communication interface 16 and the I2C / I3C communication master controller 3. When it is necessary to test the I2C / I3C communication function, the four-wire SPI master controller 2 can disable the channel selection control terminal 146 through the second IO control terminal 2146 and control the third IO control terminal 217 to close the two-wire switching switch 17. In this way, while testing the I2C / I3C communication function, the multiplexer 14 can be turned off (or the multiplexer 14 can be made not to work), the CS terminal level can be kept high, and the SPI communication can be terminated. The whole process can be completed by remotely configuring the four-wire SPI master controller 2, without having to manually change the circuit repeatedly according to the test requirements, thereby improving the test efficiency of the entire MEMS sensor device test device.

[0054] In the MEMS sensor device testing device provided by the present invention, the four-wire SPI master controller 2 is not limited to a specific model. As long as it can act as a master device to transmit SPI communication protocol and read / write commands to the MEMS sensor device 112, it is acceptable. For ease of understanding by those skilled in the art, the four-wire SPI master controller 2 is preferably selected from the NI 845X series, such as NI-8451 or NI8452. It can not only be used as a four-wire SPI master controller, but also as an I2C master controller. It is also equipped with a variety of IO ports to meet custom control requirements. When it is necessary to test the three-wire and four-wire SPI functions and the I2C function, no additional equipment is required. Only one master controller needs to be connected, which can reduce the cost of selecting different four-wire SPI master controllers and I2C master controllers at the same time. As an example, the I2C / I3C communication master controller 3 provided by this invention can be the PGY-I3C-EX-PD I3C controller from Prodigy. It can be used as both an I3C communication master controller and an I2C communication master controller without separate selection. It can simultaneously test the I2C and I3C communication functions of microelectromechanical sensors.

[0055] In summary, the test device body of the microelectromechanical sensor device test apparatus provided by the present invention has a simple structure and low cost. Even without purchasing a dedicated three-wire SPI master controller during the R&D and testing phase, it can rely on the existing four-wire SPI master controller to verify the three-wire and four-wire SPI functions of the microelectromechanical sensor 112 under test by using the existing four-wire SPI master controller in conjunction with the test device body. This saves a lot of equipment procurement costs, improves testing efficiency, and avoids the problem of extended product testing cycles caused by a shortage of testing equipment.

[0056] It should be noted that any modifications made by those skilled in the art to the specific embodiments of the present invention do not depart from the scope of the claims. Accordingly, the scope of the claims is not limited to the foregoing specific embodiments.

Claims

1. A micro-electro-mechanical sensor device testing apparatus, characterized by It comprises a test device body, the test device body comprises: a sample placement area for placing N micro-electro-mechanical sensor devices, wherein N is a positive integer, each of the N micro-electro-mechanical sensor devices is provided with a four-wire SPI signal terminal, and the four-wire SPI signal terminal comprises an SCK terminal, an SDI terminal, a CS terminal and an SDO terminal; a communication switching unit for three-four-wire SPI communication switching, comprising a first input end, a second input end, a third input end, a first output end, a second output end, a third output end and a controlled end, the first input end is electrically connected with the SDI terminal of the N micro-electro-mechanical sensor devices; the second input end is electrically connected with the CS terminal of a micro-electro-mechanical sensor device to be tested in the N micro-electro-mechanical sensor devices; the third input end is electrically connected with the SDO terminal of the N micro-electro-mechanical sensor devices; an SPI interface comprising an SCK clock input end, a slave device signal input end, a chip selection end and a slave device signal output end, the SCK clock input end is electrically connected with the SCK terminal of the N micro-electro-mechanical sensor devices; the slave device signal input end is electrically connected with the first output end, the chip selection end is electrically connected with the second output end, and the slave device signal output end is electrically connected with the third output end, the communication switching unit is controlled to switch between a first output state and a second output state, when the communication switching unit is in the first output state, the first input end is connected to the first output end; the second input end is connected to the second output end; and the third input end is connected to the third output end; when the communication switching unit is in the second output state, the first input end is disconnected from the first output end and connected to the third output end; the second input end is disconnected from the second output end and grounded; and the third input end is disconnected from the third output end and configured as a high resistance state, the micro-electro-mechanical sensor device test device further comprises a multiplexer, the multiplexer comprises an output channel connection end, a channel selection control end and N input channel connection ends, the micro-electro-mechanical sensor device test device further comprises a bidirectional logic level converter, the bidirectional logic level converter comprises a first pull-up level input port, a second pull-up level input port, four first logic level ports and four second logic level ports, the test device body further comprises a two-wire switching switch and an I2C / I3C communication interface, the I2C / I3C communication interface comprises an SCL clock signal terminal and an SDA digital signal terminal, the SCL clock signal terminal is electrically connected to the second logic level port for converting the SCK terminal level through the two-wire switching switch; the SDA digital signal terminal is electrically connected to the second logic level port for converting the SDI terminal level through the two-wire switching switch; and the two-wire switching switch comprises two states of closing and opening.

2. The micro-electromechanical sensor device testing apparatus according to claim 1, characterized in that It further comprises a four-wire SPI master, The four-wire SPI master controller includes an SCK pin, a MOSI pin, a CS pin, and a MISO pin, The SCK clock input end is connected to the SCK pin of the four-wire SPI master controller; The slave device signal input end is connected to the MOSI pin of the four-wire SPI master controller; The chip select end is connected to the CS pin of the four-wire SPI master controller; The slave device signal output end is connected to the MISO pin of the four-wire SPI master controller.

3. The micro-electro-mechanical sensor device testing apparatus according to claim 1, wherein, when the micro-electro-mechanical sensor device is tested for four-wire SPI communication function, the communication switching unit works in the first output state; the four-wire SPI master controller serves as a master device; the micro-electro-mechanical sensor device serves as a slave device.

4. The micro-electro-mechanical sensor device testing apparatus according to claim 3, wherein, when the micro-electro-mechanical sensor device is tested for three-wire SPI communication function, the communication switching unit works in the first output state, and the four-wire SPI master controller configures the working mode of the micro-electro-mechanical sensor device in a register as three-wire to realize the multiplexing of the transceiver at the SDI terminal of the micro-electro-mechanical sensor device by using the four-wire SPI communication mode; when only the write operation function of the three-wire SPI needs to be verified, the communication switching unit remains in the first output state, and the four-wire SPI master controller writes the register address and operation data into the micro-electro-mechanical sensor device; when the read operation function of the three-wire SPI needs to be further verified, the communication switching unit is switched from the first output state to the second output state after the four-wire SPI master controller sends the read register address in the read operation instruction to the micro-electro-mechanical sensor device, at this time, the SDI terminal of the micro-electro-mechanical sensor device returns the data of the read register, which is fed back to the MISO pin of the four-wire SPI master controller through the third output end; when the read operation of the three-wire SPI is completed, the communication switching unit is switched from the second output state to the first output state, at this time, the CS terminal of the micro-electro-mechanical sensor device is pulled high by the four-wire SPI master controller, and the read operation communication of the three-wire SPI is ended.

5. The micro-electro-mechanical sensor device testing apparatus according to claim 1, wherein, the N input channel connection ends are respectively connected to the CS terminals of the N micro-electro-mechanical sensor devices; the output channel connection end is connected to the second input end of the communication switching unit; the channel selection control end is used to receive an external control signal to connect any input channel connection end with the output channel connection end; the CS terminals of the N micro-electro-mechanical sensors are connected to the high level state through pull-up resistors.

6. The micro-electro-mechanical sensor device testing apparatus according to claim 5, wherein, the four first logic level ports and the four second logic level ports are one-to-one corresponding. The four first logic level ports are pulled up to the level of the first pull-up level input port by default; The four second logic level ports are pulled up to the level of the second pull-up level input port by default; The four first logic level ports are respectively electrically connected to the SCK terminals of the N micro-electro-mechanical sensor devices, the SDI terminals of the N micro-electro-mechanical sensor devices, the output channel connection terminals of the multiplexer, and the SDO terminals of the N micro-electro-mechanical sensor devices; The four second logic level ports are respectively electrically connected to the SCK clock input terminal of the SPI interface, and the first input terminal, the second input terminal, and the third input terminal of the communication switching unit.

7. The micro-electro-mechanical sensor device testing apparatus according to claim 6, wherein an external DC power supply or a reference power supply output terminal provided on the testing apparatus body is used to provide an IO reference voltage from a device to the first pull-up level input port; an IO reference voltage from a master device is provided to the second pull-up level input port by a VDDIO port of an external communication master.

8. The micro-electro-mechanical sensor device testing apparatus according to claim 1, wherein the N micro-electro-mechanical sensor devices placed in the sample placement area include micro-electro-mechanical gyroscopic devices and / or micro-electro-mechanical accelerometers and / or micro-electro-mechanical magnetic sensors and / or micro-electro-mechanical optical image stabilizers.

9. The micro-electro-mechanical sensor device testing apparatus according to claim 1, wherein the sample placement area is provided with a test carrier, and the four-wire SPI signal terminals of the micro-electro-mechanical sensor devices are inserted into the corresponding test carrier; or the sample placement area is provided with PCB package pads for the micro-electro-mechanical sensor devices, and the four-wire SPI signal terminals of the micro-electro-mechanical sensor devices are welded to the corresponding PCB package pads.

10. The micro-electro-mechanical sensor device testing apparatus according to claim 6, wherein when the two-wire switching switch is closed, the second logic level port used to convert the SCK terminal level is in communication with the SCL clock signal terminal, and the second logic level port used to convert the SDI terminal level is in communication with the SDA digital signal terminal; when the two-wire switching switch is open, the communication between the second logic level port used to convert the SCK terminal level and the SCL clock signal terminal is disconnected, and the communication between the second logic level port used to convert the SDI terminal level and the SDA digital signal terminal is disconnected.

11. The micro-electro-mechanical sensor device testing apparatus according to claim 10, further comprising an I2C / I3C communication master, a SCL pin of the I2C / I3C communication master is electrically connected to the SCL clock signal terminal; an SDA pin of the I2C / I3C communication master is electrically connected to the SDA digital signal terminal.

12. The micro-electro-mechanical sensor device testing apparatus according to claim 11, wherein ​ The four-wire SPI master further comprises a VDDIO port electrically connected to the second pull-up level input port; The I2C / I3C communication master further comprises a VDDIO port electrically connected to the second pull-up level input port.

13. The micro-electro-mechanical sensor device testing apparatus according to claim 12, wherein, The four-wire SPI master further comprises a first IO control terminal, a second IO control terminal, and a third IO control terminal, The first IO control terminal is electrically connected to a controlled terminal of the communication switching unit; The second IO control terminal is electrically connected to a channel selection control terminal of the multiplexer; The third IO control terminal is electrically connected to a controlled terminal of the two-wire switching switch.

14. The micro-electro-mechanical sensor device testing apparatus according to claim 13, wherein, When testing the three-wire SPI and / or four-wire SPI function is needed, the four-wire SPI master controls the two-wire switching switch to be open through the third IO control terminal; When testing the I2C / I3C communication function is needed, the four-wire SPI master closes the multiplexer through the second IO control terminal, and closes the two-wire switching switch through the third IO control terminal.

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