CN112698981B

CN112698981B - Protection circuit and method for preventing single chip microcomputer reset signal from losing efficacy

Info

Publication number: CN112698981B
Application number: CN202110021506.0A
Authority: CN
Inventors: 赵迪; 肖利华; 李祥; 童斌
Original assignee: Chongqing Changan New Energy Automobile Technology Co Ltd
Current assignee: Deep Blue Automotive Technology Co ltd
Priority date: 2021-01-08
Filing date: 2021-01-08
Publication date: 2023-05-23
Anticipated expiration: 2041-01-08
Also published as: CN112698981A

Abstract

The invention provides a protection circuit and a method for preventing a reset signal of a single chip microcomputer from losing, which relate to the technical field of vehicle domain controllers and comprise a main single chip microcomputer, a vehicle power supply, an LDO power supply, an SBC power supply and a monitoring single chip microcomputer, wherein the SBC power supply is electrically connected with the vehicle power supply to charge the main single chip microcomputer, and the SBC power supply is in SPI communication with the main single chip microcomputer and is used for controlling a reset pin on the main single chip microcomputer; the LDO power supply is electrically connected with the vehicle power supply, charges for the monitoring singlechip, and the main singlechip carries out SPI communication with the monitoring singlechip, and the monitoring singlechip is electrically connected with the SBC power supply for wake-up the SBC power supply in deep dormancy. The problem that the SBC power supply cannot reset the singlechip when the reset pin of the singlechip is invalid is solved, and the safety performance of the vehicle controller is improved.

Description

Protection circuit and method for preventing single chip microcomputer reset signal from losing efficacy

Technical Field

The invention relates to the technical field of vehicle domain controllers of new energy vehicle control systems, in particular to a protection circuit and a protection method for preventing a reset signal of a singlechip from being invalid.

Background

With the improvement of the safety performance of automobiles, if a controller in the automobile is in a dead halt state, drivers can be influenced to control the automobile, and safety risks exist. Therefore, the controller must have a self-resetting function to ensure that the vehicle can continue to work after a short period of out-of-control so as to ensure the final safety of personnel in the vehicle.

The current power supply in the vehicle controller is gradually changed into an SBC power supply (system base chip power supply), a DCDC power supply and an LDO power supply from a previous simple DCDC power supply (switch stabilized voltage power supply) and an LDO power supply (low dropout linear stabilized voltage power supply), the SBC power supply is more powerful than the previous DCDC power supply or LDO power supply in safety performance, the SBC power supply can be communicated with an MCU (single chip microcomputer) to judge whether the single chip microcomputer has faults or not, and when the single chip microcomputer has faults and crashes, the SBC power supply RESETs the single chip microcomputer through a RESET pin. However, when the RESET pin of the singlechip is in failure, the SBC power supply cannot RESET the singlechip, the controller is always halted, and the danger to vehicles and personnel on the vehicles is increased.

Therefore, it is necessary to develop a protection circuit and method for preventing the single chip microcomputer reset signal from failing.

Disclosure of Invention

Therefore, the invention aims to provide a protection circuit for preventing the reset signal of the singlechip from being invalid, which is used for solving the problem that an SBC power supply cannot reset the singlechip when the reset pin of the singlechip in a vehicle controller is invalid.

In a first aspect, the invention provides a protection circuit for preventing a reset signal of a singlechip from being invalid, which comprises an LDO power supply, a monitoring singlechip, an SBC power supply and a main singlechip;

the LDO power supply is electrically connected with the monitoring singlechip and supplies power for the monitoring singlechip;

the monitoring singlechip is electrically connected with the SBC power supply and is used for waking up the SBC power supply when the SBC power supply is in deep dormancy;

the SBC power supply is electrically connected with the main singlechip and is used for supplying power to the main singlechip, carrying out SPI communication with the main singlechip and controlling a reset pin of the main singlechip;

the main singlechip is electrically connected with the monitoring singlechip, and the main singlechip is in SPI communication with the monitoring singlechip.

Further, the LDO power supply and the SBC power supply are respectively and electrically connected with a vehicle power supply, and the vehicle power supply is respectively powered by the LDO power supply and the SBC power supply.

In a second aspect, the present invention also provides a protection method for preventing the failure of the reset signal of the singlechip, which includes the following steps:

step S1, when a RESET pin of a main singlechip is invalid, an SBC power supply cannot communicate with the main singlechip through an SPI interface;

step S2, after setting the duration of communication failure between the SBC power supply and the main singlechip as a first preset time T1, the SBC power supply 10 enters a deep sleep stage;

step S3, setting the duration of the communication failure between the monitoring singlechip and the main singlechip as a second preset time T2, and when the second preset time T2 is greater than the first preset time T1, powering off and powering off the main singlechip, and waking up the SBC power supply by the monitoring singlechip;

and S4, after the SBC power supply is awakened, the SBC power supply supplies power to the main singlechip again, and the main singlechip restarts normal operation.

The invention has the following beneficial effects:

the protection circuit and the method for preventing the single chip microcomputer reset signal from losing are mainly applied to a vehicle controller with high safety, and the technical problem that the SBC power supply cannot reset the single chip microcomputer when the single chip microcomputer reset pin is lost is solved by the invention, so that the safety performance of the vehicle controller is improved, and the safety of personnel on the vehicle is ensured.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings that are needed in the description of the embodiments or the prior art will be briefly described, and it is obvious that the drawings in the description below are some embodiments of the present invention, and other drawings can be obtained according to the drawings without inventive effort for a person skilled in the art.

FIG. 1 is a schematic diagram of a protection circuit for preventing a reset signal of a singlechip from being invalid;

FIG. 2 is a flow chart of a protection method for preventing the failure of a reset signal of a singlechip;

in the figure:

10-SBC power supply, 11-main singlechip, 12-monitoring singlechip, 13-LDO power supply, 14-vehicle power supply.

Detailed Description

As shown in fig. 1, a protection circuit for preventing the failure of a reset signal of a single-chip microcomputer comprises a vehicle power supply 14, an LDO power supply 13, a main single-chip microcomputer 11, a monitoring single-chip microcomputer 12 and an SBC power supply 10, wherein,

the SBC power supply 10 is electrically connected with a battery with a vehicle power supply of 12V, and converts the voltage of the vehicle power supply 14 into the rated voltage required by the main singlechip 11 so as to charge the main singlechip 11. The LDO power supply 13 is electrically connected with a 12V storage battery of the vehicle power supply 14, and converts the voltage of the vehicle power supply into the rated voltage required by the monitoring singlechip 12 so as to charge the monitoring singlechip 12. The SBC power supply 10 is also communicated with the main singlechip 11 through a first SPI interface on the main singlechip and is used for controlling a reset pin on the main singlechip 11. The master singlechip 11 communicates with the monitoring singlechip 12 through a second SPI interface on the master singlechip. And the monitoring singlechip 12 is electrically connected with the SBC power supply 10, and the monitoring singlechip 12 is used for waking up the SBC power supply 10 when the SBC power supply 10 is in deep dormancy.

As shown in fig. 2, a protection method for preventing the failure of a reset signal of a single-chip microcomputer comprises the following steps:

step S1, when the RESET pin of the main singlechip is invalid, the SBC power supply cannot communicate with the main singlechip through the SPI interface.

In step S2, after setting the duration of time for which the SBC power supply and the main singlechip still maintain communication failure as the first preset time T1, the SBC power supply 10 enters the deep sleep stage.

And S3, setting the duration of the communication failure between the monitoring singlechip and the main singlechip as a second preset time T2, and when the second preset time T2 is greater than the first preset time T1, powering off and powering off the main singlechip, and waking up the SBC power supply by the monitoring singlechip.

And S4, after the SBC power supply is awakened, the SBC power supply 10 supplies power to the main singlechip again, and the main singlechip restarts normal operation.

When the RESET pin of the main singlechip is normal: after the main singlechip 11 is halted, the SBC power supply 10 cannot communicate with the main singlechip 11 through the SPI, at the moment, the SBC power supply 10 outputs a RESET signal to the main singlechip 11 to RESET the main singlechip 11, and after the RESET is successful, the main singlechip 11 and the SBC power supply 10 continue to normally communicate through the SPI.

When the RESET pin of the main singlechip is abnormal: because the RESET pin of the main singlechip 11 is invalid, after the main singlechip 11 is halted, the SBC power supply 10 cannot communicate with the main singlechip 11 through the SPI, and the SBC power supply 10 outputs a RESET signal to the main singlechip 11 and cannot RESET the main singlechip 11; after the SBC power supply 10 fails to communicate with the main singlechip 11 for a certain time T1, the SBC power supply 10 enters a deep sleep stage,

when the SBC power supply 10 is in deep sleep, the power supply of the main singlechip 11 is turned off. After the master singlechip 11 is halted, SPI communication between the monitoring singlechip 12 and the master singlechip 11 also fails, and the communication failure time T2 between the monitoring singlechip 12 and the master singlechip 11 also occurs. When T2 is less than or equal to T1, the monitoring singlechip 12 cannot wake up the SBC power supply 10, and when T2 is more than T1, the SBC power supply 10 is deeply dormant, the main singlechip 11 is powered off at the moment, and the monitoring singlechip 12 wakes up the SBC power supply 10. When the SBC power supply 10 is awakened, the SBC power supply 10 supplies power to the main singlechip 11 again, which is equivalent to restarting the main singlechip 11; the main singlechip 11 is restarted and then works normally.

The protection circuit and the method for preventing the single-chip microcomputer reset signal from being invalid are mainly applied to a vehicle controller with high safety, and solve the problem that an SBC power supply cannot reset a main single-chip microcomputer when the reset pin of the main single-chip microcomputer is invalid due to the fact that the single-chip microcomputer in the controller is easy to crash and the reset pin with a certain risk is invalid.

Claims

1. A protection circuit for preventing a reset signal of a singlechip from losing efficacy is characterized in that: comprises an LDO power supply (13), a monitoring singlechip (12), an SBC power supply (10) and a main singlechip (11);

the LDO power supply (13) is electrically connected with the monitoring singlechip (12), and the LDO power supply (13) supplies power for the monitoring singlechip (12);

the monitoring singlechip (12) is electrically connected with the SBC power supply (10), and the monitoring singlechip (12) is used for waking up the SBC power supply (10) when the SBC power supply (10) is in deep dormancy;

the SBC power supply (10) is electrically connected with the main singlechip (11), and the SBC power supply (10) is used for supplying power to the main singlechip (11), carrying out SPI communication with the main singlechip (11) and controlling a reset pin of the main singlechip (11);

the main singlechip (11) is electrically connected with the monitoring singlechip (12), and the main singlechip (11) is in SPI communication with the monitoring singlechip (12).

2. The protection circuit for preventing a single-chip microcomputer reset signal from being invalid according to claim 1, wherein: the LDO power supply (13) and the SBC power supply (10) are respectively and electrically connected with the vehicle power supply (14), and the vehicle power supply (14) respectively supplies power for the LDO power supply (13) and the SBC power supply (10).

3. The protection method for preventing the single-chip microcomputer reset signal from losing efficacy is characterized by comprising the following steps:

step S2, after setting the duration of time for which the SBC power supply and the main singlechip still keep communication failure as a first preset time T1, the SBC power supply 10 enters a deep sleep stage;

step S3, setting the duration of the communication failure between the monitoring singlechip and the main singlechip as a second preset time T2, and if the second preset time T2 is greater than the first preset time T1, powering off and powering off the main singlechip, and waking up the SBC power supply by the monitoring singlechip;