Automatic switching circuit for starting secure digital card

Abstract

The invention relates to an automatic switching circuit for starting a secure digital card, the automatic switching circuit is respectively in communication connection with the secure digital card and a main control chip of an intelligent driving domain controller, and the main control chip is integrated with a system-on-chip and is in communication connection with a flash memory; wherein the automatic switching circuit comprises a first triode and a second triode which are connected with each other, the first triode is connected with a card slot corresponding to the secure digital card and is connected with the system-on-chip, and the second triode is connected with the system-on-chip. The efficiency can be improved, and the time cost is saved.

Description

Technical Field

[0001] The present invention relates to the technical field of intelligent driving, and more particularly to an automatic switching circuit for starting with a secure digital card. Background Art

[0002] Most of the existing starting methods of automotive intelligent driving domain controllers are to load programs through internal storage chips such as flash memories for starting. If the flash memory is damaged and requires after-sales repair, or when secondary development is needed, a starting mode of another secure digital card (SD card) is usually required.

[0003] The peripheral configuration circuit of a conventional controller main control chip is as Figure 1 shown. It configures the starting mode of the main control chip by means of pull-up / pull-down thick film patch resistors in a selective pasting manner. If the starting mode of the main control chip needs to be changed to the starting mode of the SD card, the circuit board of the controller needs to be repaired and processed, which is cumbersome and time-consuming. Summary of the Invention

[0004] To solve the above problems in the prior art, the present invention provides an automatic switching circuit for starting with a secure digital card, which does not require the circuit board of the controller to be repaired, so as to improve efficiency and save costs.

[0005] An automatic switching circuit for starting with a secure digital card provided by the present invention is respectively communicatively connected to a secure digital card and a main control chip of an intelligent driving domain controller. The main control chip integrates a system-on-chip and is communicatively connected to a flash memory. Among them, the automatic switching circuit includes a first triode and a second triode connected to each other. The first triode is connected to the card slot corresponding to the secure digital card and is connected to the system-on-chip, and the second triode is connected to the system-on-chip.

[0006] Further, the base of the first triode is connected to the card slot corresponding to the secure digital card through a first resistor, the emitter of the first triode is connected to a first power supply, and the collector of the first triode is connected to the base of the second triode through a second resistor, is connected to one pin of the system-on-chip through a third resistor, is connected to another pin of the system-on-chip through a fourth resistor, and is grounded through a fifth resistor.

[0007] Further, the emitter of the second triode is grounded, and the collector of the second triode is connected to one pin of the system-on-chip through a sixth resistor and is connected to a second power supply through a seventh resistor.

[0008] Further, the first triode is of the PDTA114ET model.

[0009] Further, the second triode is of the BC817-40 model.

[0010] Further, the resistance values of the first resistor, the second resistor, the third resistor, the fourth resistor, and the sixth resistor are all 1K ohms.

[0011] Further, the resistance values of the fifth resistor and the seventh resistor are both 10K ohms

[0012] An automatic switching circuit for secure digital card startup provided by the present invention can detect whether a secure digital card is inserted into a card slot, and according to a trigger signal sent by the secure digital card, change the startup mode of the main control chip through the automatic switching circuit, without the need for operations such as controller repair, which can save a large amount of time cost. Description of the Drawings

[0013] Figure 1 is a schematic diagram of a startup mode configuration circuit of a main control chip of a controller in the prior art.

[0014] Figure 2 is a connection schematic diagram of an automatic switching circuit for secure digital card startup according to the present invention.

[0015] Figure 3 is a structural schematic diagram of an automatic switching circuit for secure digital card startup according to the present invention. Detailed Embodiments

[0016] The following presents the preferred embodiments of the present invention in conjunction with the drawings and describes them in detail.

[0017] As Figure 2 shown, an automatic switching circuit 10 for secure digital card startup provided by the present invention is respectively communicatively connected to a secure digital card 20 and a main control chip 30 of an intelligent driving domain controller. Among them, the main control chip 30 integrates a system-on-chip (SOC), and it is also communicatively connected to a flash memory 40. In the normal mode, the startup mode of the main control chip 30 is to start by loading a program from the flash memory; when the secure digital card 20 is inserted into the corresponding card slot, the automatic switching circuit 10 receives a trigger signal from the secure digital card 20, and the startup mode of the main control chip 30 is switched to start by loading a program from the secure digital card. In this way, the automatic switching process of the main control chip from the flash memory to the secure digital card startup is realized. In this embodiment, the main control chip 30 is an existing chip, for example, it can be a chip of the TDA4 model.

[0018] As Figure 3As shown, the automatic switching circuit 10 includes a first triode 11 and a second triode 12 connected to each other. The first triode 11 is connected to the card slot corresponding to the secure digital card 20 and is connected to the system-on-chip in the main control chip 30. The second triode 12 is connected to the system-on-chip in the main control chip 30.

[0019] Specifically, the base of the first triode 11 is connected to the card slot corresponding to the secure digital card 20 through a first resistor R1. The emitter of the first triode 11 is connected to the first power supply VDD. The collector of the first triode 11 is connected to the base of the second triode 12 through a second resistor R2, is connected to one pin SOC_BOOT0 of the system-on-chip through a third resistor R3, is connected to another pin SOC_BOOT6 of the system-on-chip through a fourth resistor R4, and is grounded through a fifth resistor R5.

[0020] The emitter of the second triode 12 is grounded. The collector of the second triode 12 is connected to one pin SOC_BOOT3 of the system-on-chip through a sixth resistor R6 and is connected to the second power supply VSOC_MCU through a seventh resistor R7.

[0021] In this embodiment, the first triode 11 is selected as PDTA114ET, and the second triode 12 is selected as BC817-40. The resistance values of the first resistor R1, the second resistor R2, the third resistor R3, the fourth resistor R4, and the sixth resistor R6 are all 1K ohms. The resistance values of the fifth resistor R5 and the seventh resistor R7 are both 10K ohms. It should be understood that the first triode 11 and the second triode 12 can also be selected as other models of small-signal NPN triodes according to needs, and the corresponding resistance values can also vary with the models.

[0022] The working principle of the automatic switching circuit 10 of the present invention is as follows:

[0023] In the normal mode, the intelligent driving domain controller starts by loading a program through the flash memory 40. At this time, the secure digital card 20 is not inserted into the corresponding card slot, and the automatic switching circuit 10 will not receive the corresponding trigger signal. At this time, the first triode 11 does not receive the trigger signal SDCard_EN, that is, the first triode 11 and the second triode 12 are not conducting, SOC_BOOT0 is at a low level, SOC_BOOT6 is at a low level, and SOC_BOOT3 is at a high level. At this time, according to the flash memory startup and secure smart card startup configuration table of the main control chip 30 (see Table 1), the startup mode of the main control chip 30 is to start by loading a program through the flash memory. Among them, according to the predefined configuration method in the flash memory startup and secure smart card startup configuration table of the main control chip 30, when the secure digital card 20 is inserted into the corresponding card slot, the secure digital card 20 will send out a trigger signal. At this time, the first triode 11 receives the trigger signal SDCard_EN, causing the first triode 11 and the second triode 12 to conduct. At this time, SOC_BOOT0 is at a high level, SOC_BOOT6 is at a high level, and SOC_BOOT3 is at a low level. According to the flash memory startup and secure smart card startup configuration table of the main control chip 30, the startup mode of the main control chip 30 is switched to start by loading a program through the secure digital card, thus realizing the automatic switching process from the flash memory to the secure digital card startup. Table 1 Chip Flash Memory Startup and Secure Smart Card Startup Configuration Table Startup method Boot 0 Boot 6 MCUBoot 3 Flash memory 0 0 1 Secure smart card 1 1 0

[0024] The present invention is a pure hardware solution that does not require the implementation of software programming and other solutions. It detects whether the secure digital card is inserted into the card slot and, according to the trigger signal sent by the secure digital card, changes the startup mode of the main control chip through the automatic switching circuit, without the need for work such as controller repair, which can save a large amount of time cost. Compared with Figure 1 the startup mode switching solution of selecting and pasting thick film resistors in [reference], the present invention does not require repair of the controller's circuit board, effectively improving the efficiency of after-sales repair and secondary development and debugging, and reducing the time cost.

[0025] The above-mentioned are only the preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various changes can be made to the above embodiments of the present invention. That is, all simple, equivalent changes and modifications made according to the claims and the content of the specification of the present invention application shall fall within the scope of the claims of the present invention patent. The content not described in detail in the present invention is all conventional technical content.

Claims

1. An automatic switching circuit activated by a secure digital card, characterized in that: The automatic switching circuit is respectively connected to the secure digital card and the main control chip of the intelligent driving domain controller in communication, and the main control chip integrates a system-level chip and is connected to the flash memory in communication; The automatic switching circuit includes a first transistor and a second transistor connected to each other, the first transistor is connected to the card slot corresponding to the secure digital card and connected to the system-level chip, and the second transistor is connected to the system-level chip.

2. The automatic switching circuit for starting a secure digital card according to claim 1, characterized in that: The base of the first transistor is connected to the card slot corresponding to the secure digital card through a first resistor, the emitter of the first transistor is connected to a first power supply, the collector of the first transistor is connected to the base of the second transistor through a second resistor, connected to one of the pins of the system-level chip through a third resistor, connected to another pin of the system-level chip through a fourth resistor, and grounded through a fifth resistor.

3. The automatic switching circuit for starting a secure digital card according to claim 2, characterized in that: The emitter of the second transistor is grounded, the collector of the second transistor is connected to one of the pins of the system-level chip through a sixth resistor, and is connected to a second power supply through a seventh resistor.

4. The automatic switching circuit for starting a secure digital card according to claim 1, characterized in that: The first transistor is of model PDTA114ET.

5. The automatic switching circuit for starting a secure digital card according to claim 1, characterized in that: The second transistor is BC817-40.

6. The automatic switching circuit for starting a secure digital card according to claim 3, characterized in that: The resistance values ​​of the first resistor, the second resistor, the third resistor, the fourth resistor and the sixth resistor are all 1K ohms.

7. The automatic switching circuit for starting a secure digital card according to claim 3, characterized in that: The resistance values ​​of the fifth resistor and the seventh resistor are both 10K ohms.

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