Reset circuit and reset system of vehicle-mounted Ethernet PHY chip
By combining the Ethernet switch, MCU, and reset chip unit in a circuit design, the reliability and resource consumption issues of PHY chip reset in the automotive environment are solved, and reliable reset in multiple ways is achieved, improving the stability and flexibility of the automotive Ethernet system.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- ZHIDAO NETWORK TECH (BEIJING) CO LTD
- Filing Date
- 2025-06-27
- Publication Date
- 2026-06-23
AI Technical Summary
Existing automotive Ethernet PHY chip reset circuits are unreliable in automotive environments, have limited functionality, inaccurate reset timing, are susceptible to electromagnetic interference, and occupy multiple MCU GPIO resources when multiple PHY chips are reset.
The circuit design employs a combination of Ethernet switch unit, MCU unit, PHY chip unit and reset chip unit, and achieves reliable reset of PHY chip through multiple methods, including power-on reset, manual reset and fault detection reset, reducing the occupation of MCU GPIO resources.
It improves the reliability and flexibility of the reset circuit in the vehicle environment, ensures that the PHY chip can be reliably reset under abnormal conditions, reduces the risk of reset failure, and saves MCU resources.
Smart Images
Figure CN224401509U_ABST
Abstract
Description
Technical Field
[0001] This application relates to automotive electronics technology and automotive Ethernet technology, and in particular to a reset circuit and an automotive Ethernet PHY chip reset system. Background Technology
[0002] With the rapid development of automotive intelligence and connectivity, automotive Ethernet is being used more and more widely in automotive electronic systems. As a key component of automotive Ethernet communication, the automotive Ethernet physical layer (PHY) chip's normal and stable operation is crucial for the entire automotive network system. If abnormal situations occur during system startup or operation (such as power fluctuations or communication failures), a reliable reset circuit is needed to ensure that the PHY chip can be correctly reset and return to normal working condition.
[0003] However, some existing reset circuit designs suffer from insufficient reliability and limited functionality in automotive environments, making it difficult to meet the increasingly complex demands of automotive Ethernet systems. For example, some reset circuits can only perform simple power-on reset functions. When using multiple PHY chips, multiple GPIO pins are required to control the reset, and they lack manual reset and automatic fault detection reset functions, making them inflexible and inconvenient for system debugging and troubleshooting. Furthermore, in harsh conditions such as electromagnetic interference and power supply noise in the automotive environment, the reset signal is susceptible to interference, leading to malfunctions and affecting the stability and reliability of the system. Utility Model Content
[0004] This application provides a reset circuit and an in-vehicle Ethernet PHY chip reset system to provide a reset circuit with multiple reset methods, as well as the reliability, functionality and flexibility of the reset circuit in an in-vehicle environment.
[0005] The embodiments of this application adopt the following technical solutions:
[0006] In a first aspect, embodiments of this application provide a reset circuit, wherein the circuit includes: an Ethernet switch unit, an MCU unit, a PHY chip unit, and a reset chip unit, wherein the Ethernet switch unit is connected to a plurality of the PHY chip units, the plurality of PHY chip units are connected to the reset chip unit, the Ethernet switch unit is connected to the MCU unit, and the MCU unit is connected to the reset chip unit.
[0007] In some embodiments, when power is on, the reset chip unit powers on and resets at least one of the plurality of PHY chip units; or / and,
[0008] The MCU unit is driven by the button circuit to start the reset chip unit to power on and reset at least one of the multiple PHY chip units.
[0009] In some embodiments, the MCU unit is further used for
[0010] When the power supply is unstable and the voltage is lower than a preset threshold, the reset chip unit controls the power-on reset of at least one of the multiple PHY chip units.
[0011] In some embodiments, the MCU unit includes
[0012] The RGMII interface communicates with the Ethernet SWITCH unit to monitor status signals.
[0013] The GPIO port is used to output a low-level signal to the MR terminal of the reset chip unit when a fault occurs in the PHY chip unit.
[0014] In some embodiments, the Ethernet switch unit employs a communication switching chip, the RGMII interface of the communication switching chip is connected to the MCU unit, and the SGMII interface of the communication switching chip is connected to the PHY chip unit.
[0015] In some embodiments, the PHY chip unit is a communication network chip, which is connected to an Ethernet switching network composed of SWITCH chips via an SGMII interface.
[0016] In some embodiments, the MCU unit includes an automotive-grade MCU chip.
[0017] In some embodiments, the reset chip unit includes
[0018] The MR pin is connected to GPIO1 in the MCU unit;
[0019] The RST pin is connected to the reset pin in the PHY chip unit;
[0020] The CT pin is connected to the capacitor C to ground, and the reset time in the reset chip unit can be adjusted by adjusting the capacitance value of capacitor C.
[0021] In some embodiments, the reset chip is a microcontroller chip.
[0022] Secondly, embodiments of this application also provide an in-vehicle Ethernet PHY chip reset system, which includes the reset circuit described in the first aspect.
[0023] The at least one technical solution adopted in this application embodiment can achieve the following beneficial effects: the reset circuit adopts an Ethernet switch unit, an MCU unit, a PHY chip unit, and a reset chip unit. The Ethernet switch unit is connected to multiple PHY chip units, the multiple PHY chip units are connected to the reset chip unit, and the Ethernet switch unit is connected to the MCU unit. The above-mentioned reset circuit improves reliability, functionality, and flexibility in an automotive environment and can perform resets in multiple ways. Attached Figure Description
[0024] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings:
[0025] Figure 1 This refers to the reset structure of the vehicle-mounted Ethernet physical layer PHY chip in related technologies.
[0026] Figure 2 This is a schematic diagram of the internal structure of the reset circuit in an embodiment of this application;
[0027] Figure 3 This is a schematic diagram of the reset circuit in an embodiment of this application. Detailed Implementation
[0028] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions of this application will be clearly and completely described below in conjunction with specific embodiments and corresponding drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.
[0029] like Figure 1 The diagram shows an existing PHY chip reset scheme for automotive Ethernet physical layers. The PHY chip's power-on reset is performed via an RC circuit, achieving a single reset upon power-up. However, this circuit's reset time is highly dependent on circuit parameters, resulting in low accuracy. Simultaneously, the PHY chip reset signal is connected to the MCU's GPIO pins, allowing for PHY chip reset via the MCU's GPIO pins. However, when resetting multiple PHY chips, multiple GPIO interfaces are required. This method suffers from inaccurate reset timing, is prone to reset failures, and consumes multiple MCU GPIO resources when resetting multiple PHY chips.
[0030] To address the aforementioned shortcomings, the embodiments of this application provide a reset circuit that solves the problems of inaccurate reset time, easy reset failure, occupation of multiple MCU GPIO resources when resetting multiple PHY chips, and lack of automatic reset design. This improves the reliability, functionality, and flexibility of the reset circuit in the automotive environment.
[0031] The technical solutions provided by the various embodiments of this application are described in detail below with reference to the accompanying drawings.
[0032] This application provides a reset circuit 200, such as... Figure 2 As shown, a schematic diagram of the internal structure of the reset circuit in this embodiment of the application is provided. The circuit includes: an Ethernet SWITCH unit 210, an MCU unit 220, a PHY chip unit 230, and a reset chip unit 240. The Ethernet SWITCH unit 210 is connected to multiple PHY chip units 230, and the multiple PHY chip units 230 are connected to the reset chip unit. The Ethernet SWITCH unit 210 is connected to the MCU unit 220.
[0033] The Ethernet switch unit 210 mainly refers to an automotive-grade Ethernet switch chip, and the MCU unit 220 can also be an automotive-grade MCU chip. The Ethernet switch unit 210 communicates with multiple PHY chip units 230, thus eliminating the need to allocate a separate GPIO resource for each PHY chip, thereby saving MCU resource consumption. The MCU unit 220 communicates with the Ethernet switch unit 210 to monitor the status signals in the Ethernet switch unit 210 and the PHY chip units 230, and uses these status signals to determine whether a fault has occurred in the current circuit or if there is an error in the data link.
[0034] The reset circuit 200 described above can solve the problem of inaccurate reset time and easy reset failure in the reset scheme of the vehicle Ethernet physical layer PHY chip, thereby enabling multiple reset methods through the MCU unit 220.
[0035] Through the aforementioned reset circuit 200, multiple PHY chip units 230 are connected to the reset chip unit, eliminating the need to allocate a separate GPIO resource for each PHY chip, thus saving MCU resource consumption and solving the problem that multiple PHY chips would occupy multiple MCU GPIO resources during reset.
[0036] In one embodiment of this application, when the power is turned on, the reset chip unit powers on and resets at least one of the plurality of PHY chip units; the reset chip unit powers on and resets at least one of the plurality of PHY chip units via a button circuit.
[0037] Scenario 1: Power-on reset. When the (system) is powered on, the reset chip unit automatically performs a system power-on reset on the PHY chip. The reset time is adjustable and more controllable, ensuring that the PHY chip completes the initialization operation before the power supply stabilizes, making the reset more reliable.
[0038] Scenario 2: Manual Reset. When a manual reset of the PHY chip is required, the chip can be reset individually by pressing a button, making the reset process more flexible. For example... Figure 3 As can be understood from the button circuit shown, the button circuit of this application may include a variety of types, as long as it meets the reset requirements.
[0039] It is understood that the "system" mentioned above could refer to the power supply system or the reset circuit system in the reset circuit.
[0040] In one embodiment of this application, the MCU unit is further configured to control the reset chip unit to power on and reset at least one of the plurality of PHY chip units when the power supply is unstable and the voltage is lower than a preset threshold.
[0041] Scenario 3: When the system power supply is unstable and the voltage is lower than the preset threshold, the reset chip performs a reset operation on the PHY chip to avoid affecting the stability of PHY operation due to unstable system power supply.
[0042] In addition, the MCU unit communicates with the SWITCH chip through the RGMII interface, and can monitor the status registers or specific status signals of the SWITCH chip and PHY chip.
[0043] If the MCU detects a fault in the PHY chip, such as a link failure or excessive data errors, the MCU will output a low-level signal to the MR terminal of the reset chip through a GPIO port to reset the PHY, thus enhancing the reset functionality.
[0044] In one embodiment of this application, the MCU unit includes an RGMII interface for communicating with the Ethernet SWITCH unit to monitor status signals; and a GPIO port for outputting a low-level signal to the MR terminal in the reset chip unit when a PHY chip unit malfunctions.
[0045] Specifically, one of the GPIO pins of the MCU unit is used to control the MR pin of the reset chip. When the GPIO pin signal is low, the reset chip outputs a reset signal through RST to reset the PHY chip.
[0046] In fault monitoring and reset scenarios, when the system power supply is unstable and the voltage is below a preset threshold, the reset chip performs a reset operation on the PHY chip to prevent the PHY's operational stability from being affected by system power instability. The MCU communicates with the SWITCH chip through the RGMII interface and can monitor the status registers or specific status signals of the SWITCH chip and the PHY chip. If the MCU detects a fault in the PHY chip, such as a link failure or excessive data errors, the MCU will output a low-level signal to the MR terminal of the reset chip through a GPIO port to reset the PHY.
[0047] In one embodiment of this application, the Ethernet switch unit employs a communication switching chip, the RGMII interface of the communication switching chip is connected to the MCU unit, and the SGMII interface of the communication switching chip is connected to the PHY chip unit.
[0048] The communication switching chip specifically uses three SGMII interfaces in the BCM89581 chip to connect to three PHY chips respectively. It also uses the RGMII interface in the BCM89581 chip to connect to the MCU unit.
[0049] In one embodiment of this application, the PHY chip unit is a communication network chip, which is connected to an Ethernet switching network composed of SWITCH chips via an SGMII interface.
[0050] The communication network chip uses the BCM89885 chip to support the SGMII interface. The three BCM89885 chips are connected to the Ethernet switching network composed of SWITCH chips through the SGMII interface. The RESET pin of the PHY chip is also connected to the RST pin of the reset chip, so that the reset chip can simultaneously perform a reset operation on the PHY chip.
[0051] Optionally, the PHY chip unit can use the BCM89885 chip, which is an automotive-grade PHY chip from Broadcom that supports 1000BASE-T1 networks.
[0052] In one embodiment of this application, the MCU unit includes an automotive-grade MCU chip.
[0053] like Figure 3As shown, the MCU unit contains a button circuit, allowing an external device to reset the PHY chip via the button. Please continue to refer to [the relevant documentation / reference]. Figure 3 One of the GPIO pins of the MCU unit is used to control the MR pin of the reset chip. When the GPIO pin signal is low, the reset chip outputs a reset signal through RST to reset the PHY chip.
[0054] Alternatively, the MCU unit can use an automotive-grade MCU chip such as the TC397 chip. This chip is an automotive-grade 32-bit microcontroller developed by Infineon Technologies, and in this embodiment, it is mainly used to implement the reset logic design of the PHY chip.
[0055] In one embodiment of this application, the reset chip unit includes an MR pin connected to GPIO1 in the MCU unit; an RST pin connected to the reset pin in the PHY chip unit; and a CT pin connected to a capacitor C to ground, used to adjust the reset time in the reset chip unit by adjusting the capacitance value of the capacitor C.
[0056] In one embodiment of this application, the reset chip is a microcontroller chip.
[0057] The reset chip unit is connected to the GPIO1 of the MCU via the MR pin, the RST pin is connected to the reset pin of the PHY chip, and the CT pin is connected to a capacitor C to ground. The reset time of the reset chip can be adjusted by adjusting the capacitance of capacitor C.
[0058] When the MR pin receives a low-level signal, the reset chip outputs a reset signal through the RST pin. In addition, the reset chip supports voltage monitoring; when system power instability causes the voltage to fall below a threshold, the reset chip will actively reset the PHY chip.
[0059] Preferably, the reset chip can be the RT9807 chip from RICHTEK.
[0060] An embodiment of this application also provides an in-vehicle Ethernet PHY chip reset system, which includes the circuit described above. The circuit includes: an Ethernet SWITCH unit, an MCU unit, a PHY chip unit, and a reset chip unit. The Ethernet SWITCH unit is connected to multiple PHY chip units, the multiple PHY chip units are connected to the reset chip unit, and the Ethernet SWITCH unit is connected to the MCU unit.
[0061] In some embodiments, when the power is on, the reset chip unit powers on and resets at least one of the plurality of PHY chip units.
[0062] The reset chip unit is activated via a button circuit to power on and reset at least one of the plurality of PHY chip units.
[0063] In some embodiments, the MCU unit is further used for
[0064] When the power supply is unstable and the voltage is lower than a preset threshold, the reset chip unit controls the power-on reset of at least one of the multiple PHY chip units.
[0065] In some embodiments, the MCU unit includes
[0066] The RGMII interface communicates with the Ethernet SWITCH unit to monitor status signals.
[0067] The GPIO port is used to output a low-level signal to the MR terminal of the reset chip unit when a fault occurs in the PHY chip unit.
[0068] In some embodiments, the Ethernet switch unit employs a communication switching chip, the RGMII interface of the communication switching chip is connected to the MCU unit, and the SGMII interface of the communication switching chip is connected to the PHY chip unit.
[0069] In some embodiments, the PHY chip unit is a communication network chip, which is connected to an Ethernet switching network composed of SWITCH chips via an SGMII interface.
[0070] In some embodiments, the MCU unit includes an automotive-grade MCU chip.
[0071] In some embodiments, the reset chip unit includes
[0072] The MR pin is connected to GPIO1 in the MCU unit;
[0073] The RST pin is connected to the reset pin in the PHY chip unit;
[0074] The CT pin is connected to the capacitor C to ground, and the reset time in the reset chip unit can be adjusted by adjusting the capacitance value of capacitor C.
[0075] In some embodiments, the reset chip is a microcontroller chip.
[0076] Based on the aforementioned automotive Ethernet PHY chip, the adoption of a reset circuit improves its reliability, functionality, and flexibility in automotive environments. Furthermore, the automotive Ethernet PHY chip supports multiple reset methods to meet diverse user needs.
[0077] The above description is merely an embodiment of this application and is not intended to limit the scope of this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of the claims of this application.
Claims
1. A reset circuit, wherein, The circuit includes: an Ethernet switch unit, an MCU unit, a PHY chip unit, and a reset chip unit. The Ethernet switch unit is connected to multiple PHY chip units, the multiple PHY chip units are connected to the reset chip unit, the Ethernet switch unit is connected to the MCU unit, and the MCU unit is connected to the reset chip unit.
2. The circuit as described in claim 1, wherein, When the power is on, the reset chip unit powers on and resets at least one of the plurality of PHY chip units; or / and, The MCU unit is driven by the button circuit to start the reset chip unit to power on and reset at least one of the multiple PHY chip units.
3. The circuit as described in claim 1, wherein, The MCU unit is also used for When the power supply is unstable and the voltage is lower than a preset threshold, the reset chip unit controls the power-on reset of at least one of the multiple PHY chip units.
4. The circuit as described in claim 1, wherein, The MCU unit includes The RGMII interface communicates with the Ethernet SWITCH unit to monitor status signals. The GPIO port is used to output a low-level signal to the MR terminal of the reset chip unit when a fault occurs in the PHY chip unit.
5. The circuit as described in claim 1, wherein, The Ethernet switch unit uses a communication switching chip. The RGMII interface of the communication switching chip is connected to the MCU unit, and the SGMII interface of the communication switching chip is connected to the PHY chip unit.
6. The circuit as claimed in claim 1, wherein, The PHY chip unit is a communication network chip, which is connected to an Ethernet switching network composed of SWITCH chips through an SGMII interface.
7. The circuit as claimed in claim 1, wherein, The MCU unit includes an automotive-grade MCU chip.
8. The circuit as claimed in claim 1, wherein, The reset chip unit includes The MR pin is connected to GPIO1 in the MCU unit; The RST pin is connected to the reset pin in the PHY chip unit; The CT pin is connected to the capacitor C to ground, and the reset time in the reset chip unit can be adjusted by adjusting the capacitance value of capacitor C.
9. The circuit as described in claim 8, wherein, The reset chip is a microcontroller chip.
10. A vehicle-mounted Ethernet PHY chip reset system, wherein, Includes the circuit as described in any one of claims 1 to 9.