TWI877016B - Control circuit and control method thereof - Google Patents

Abstract

An control circuit and control a method thereof are provided. After a first circuit provides a first signal to a preset pin of a second circuit, the first circuit controls a switch unit to convert a first voltage from a power converter into a third voltage. The third voltage provides to the second circuit to activate the second circuit to enter a firmware update mode in response to the first signal.

Description

Control circuit and control method thereof

The present invention relates to an electronic device, and in particular to a control circuit and a control method of the electronic device.

In the prior art, projection devices often use ASICs made by MediaTek (MTK) to implement multimedia application functions, as well as image receivers, audio amplifiers, and microcontrollers (MCU) operation functions. In addition, projection devices are also paired with ASICs made by Texas Instruments to control DMD (Digital Micro-mirror Device) chips, lamps, fans, etc. When using these two ASICs together, how to avoid erroneous operation that causes the system crash of the projection device is an important issue.

The "Prior Art" section is only used to help understand the content of the present invention. Therefore, the content disclosed in the "Prior Art" section may contain some content that does not constitute the common knowledge of the person skilled in the art. The content disclosed in the "Prior Art" section does not represent the problem to be solved by the content or one or more embodiments of the present invention, nor does it mean that the content or the problem has been known or recognized by the person skilled in the art before the application of the present invention.

The present invention provides a control circuit and a control method thereof, which can effectively prevent the system crash of a projection device caused by erroneous operation of the control circuit.

Other purposes and advantages of the present invention can be further understood from the technical features disclosed in the present invention.

To achieve one or part or all of the above purposes or other purposes, an embodiment of the present invention provides a control circuit, the control circuit includes a power converter, a switch unit, a first circuit and a second circuit, wherein the first circuit is coupled to the power converter, the second circuit and the switch unit, and the switch unit is coupled between the power converter and the second circuit. The switch unit is used to turn on or off the power supply path between the power converter and the second circuit. The first circuit is suitable for receiving a firmware update instruction and controlling the power converter to provide a first voltage to the switch unit according to the firmware update instruction, and the first circuit performs initial setting. After completing the initial setting, the first circuit provides a first signal to a preset pin of the second circuit. After the first circuit provides the first signal to the second circuit, the first circuit controls the switch unit to turn on the power supply path between the power converter and the second circuit, so that the switch unit converts the first voltage from the power converter into a third voltage and provides it to the second circuit, so that the second circuit is started. After the second circuit is started, it receives the first signal from the first circuit and enters the firmware update mode.

The present invention also provides a control method for a control circuit, wherein the control circuit includes a power converter, a switch unit, a first circuit and a second circuit, wherein the first circuit is coupled to the power converter, the second circuit and the switch unit, and the switch unit is coupled between the power converter and the second circuit to turn on or off the power supply path between the power converter and the second circuit. The control method includes the following steps. The first circuit is suitable for receiving a firmware update instruction and controlling the power converter to provide a first voltage to the switch unit according to the firmware update instruction, and the first circuit performs initial settings. After the first circuit completes the initial settings, a first signal is provided to a preset pin of the second circuit. After the first circuit provides the first signal to the second circuit, the first circuit controls the switch unit to turn on the path between the power converter and the second circuit. The switch unit converts the first voltage from the power converter into a third voltage and provides the third voltage to the second circuit, so that the second circuit is started. After the second circuit is started, it receives the first signal from the first circuit and enters the firmware update mode.

Based on the above, after providing the first signal to the preset pin of the second circuit, the first circuit of the embodiment of the present invention can control the switch unit to convert the first voltage from the power converter into a third voltage and provide it to the second circuit, so as to activate the second circuit to respond to the first signal and enter the firmware update mode. This can effectively prevent the second circuit from receiving the first signal of the preset pin too late and causing erroneous operation, thereby causing the system of the projection device to crash.

In order to make the above features and advantages of the present invention more clearly understood, embodiments are given below and described in detail with reference to the accompanying drawings.

The above-mentioned other technical contents, features and effects of the present invention will be clearly presented in the following detailed description of a preferred embodiment with reference to the drawings. The directional terms mentioned in the following embodiments, such as up, down, left, right, front or back, etc., are only referenced to the directions of the attached drawings. Therefore, the directional terms used are used to illustrate and are not used to limit the present invention.

FIG. 1 is a schematic diagram of a control circuit according to an embodiment of the present invention, please refer to FIG. 1. The control circuit 100 is applicable to a projection device, and may include a power converter 102, a switch unit 104, a first circuit 106, and a second circuit 108. The power converter 102 may be, for example, a power supply known to those skilled in the art, the first circuit 106 may be a display control single chip (such as an MT9266 chip), and the second circuit 108 may be a digital optical processing chip (such as a DDP442X chip), but is not limited thereto. The first circuit 106 has at least one first input-output pin P1, P2 and a second input-output pin P3, wherein the first input-output pin P1, P2 and the second input-output pin P3 may be defined as the same input-output pins P1~P3. The first circuit 106 further has a third input/output pin P4 and a fourth input/output pin P5, and the third input/output pin P4 and the fourth input/output pin P5 can be defined as the same input/output pins P4 and P5. It should be noted that the input/output pins are, for example, general-purpose input/output (GPIO) known to those skilled in the art. The first circuit 106 is coupled to the power converter 102 via the second input/output pin P3, the first circuit 106 is coupled to the switch unit 104 via the third input/output pin P4, the first circuit 106 is coupled to the default pin PIN1 of the second circuit 108 via the fourth input/output pin P5, and the switch unit 104 is coupled between the power converter 102 and the second circuit 108 to turn on or off the power supply path between the power converter 102 and the second circuit 108. The switch unit 104 can be implemented, for example, with a metal oxide semiconductor field effect transistor (MOSFET) or a bipolar junction transistor (BJT), but any element that can function as a switch is applicable to the present invention, and the present invention is not limited thereto. When power is supplied to the control circuit 100 but the control circuit 100 is not activated, the first input-output pins P1, P2 and the second input-output pin P3 can be detected and controlled. When power is supplied to the control circuit 100 and the control circuit 100 is activated, the third input-output pin P4 and the fourth input-output pin P5 can be detected or controlled. For example, when the projection device includes the control circuit 100, the power is provided to the control circuit 100 in a manner such as plugging the projection device into a power cord so that the control circuit 100 obtains power. If the user does not press the power button of the projection device, the control circuit 100 enters a standby mode. The control circuit 100 is not activated and performs basic operations with a standby voltage of, for example, 5V, such as displaying a standby indicator light or placing the infrared module in standby mode. In this standby mode, the first input/output pins P1 and P2 and the second input/output pin P3 are detected and controlled. After the projection device is plugged into a power cord, for example, when the user presses the power button of the projection device, the control circuit 100 can enter the working mode. The control circuit 100 is activated and works normally with a working voltage of, for example, 12V. In this working mode, the third input-output pin P4 and the fourth input-output pin P5 can be detected or controlled.

The first circuit 106 can receive the firmware update command CMD1 through at least one first input/output pin P1, P2. The first circuit 106 controls the power converter 102 to provide the first voltage V1 to the switch unit 104 and the second voltage V2 to the first circuit 106 according to the firmware update command CMD1. After receiving the second voltage V2, the first circuit 106 will perform initial settings, wherein the initial settings may be, for example, mute or volume settings, etc. The firmware update command CMD1 is generated, for example, by the user pressing the power button and the menu button of the projection device corresponding to at least one first input/output pin P1, P2, and then plugging the projection device into a power cord, thereby allowing the first circuit 106 to receive the firmware update command CMD1. Furthermore, the first circuit 106 may include a microcontroller 110. After a button corresponding to at least one of the first input/output pins P1 and P2 (e.g., a power button and a menu button) is pressed, the projection device is plugged into a power cord to provide power to the control circuit 100, thereby causing the first circuit 106 to receive a firmware update command CMD1 and control the power converter 102 to provide a startup voltage VSBY to the microcontroller 110. At this time, in the standby mode, the microcontroller 110 can control the first circuit 106 to output the power control signal VON from the second input-output pin P3 to the power converter 102 (as shown in Figure 1), so as to control the power converter 102 to provide the first voltage V1 to the switch unit 104, and control the power converter 102 to provide the second voltage V2 to the first circuit 106, wherein the first voltage V1 and the second voltage V2 can, for example, have the same voltage value, but are not limited to this.

In some embodiments, the method of generating the firmware update command CMD1 is not limited to using the power key and the menu key, and may also use a combination of other keys, or only use a single key. That is, in other embodiments, the firmware update command CMD1 may also be received by at least one of the first input/output pins P1 and P2, or more input/output pins that can be detected and controlled in the standby mode.

Please continue to refer to FIG. 1. In this embodiment, the first circuit 106 receives the second voltage V2 from the power converter 102 to perform initial setting. After completing the initial setting, the first circuit 106 provides the first signal VD1. In other words, after the first circuit 106 completes the initial setting, the first circuit 106 can provide the first signal VD1 to the default pin PIN1 of the second circuit 108, wherein the level of the first signal VD1 provided to the second circuit 108 can be, for example, a low voltage logic level, but is not limited thereto. After the first circuit 106 provides the first signal VD1 to the second circuit 108, the first circuit 106 controls the switch unit 104 to conduct the power supply path between the power converter 102 and the second circuit 108, so that the switch unit 104 converts the first voltage V1 from the power converter 102 into a third voltage V3, and provides the third voltage V3 to the second circuit 108 to start the second circuit 108. After being started, the second circuit 108 can receive the first signal VD1 from the first circuit 106 and enter the firmware update mode.

FIG2 is a schematic diagram of the working sequence of a control circuit according to an embodiment of the present invention. Please refer to FIG2 and FIG1. In this embodiment, when the user presses the power button and the menu button of the projection device corresponding to at least one first input-output pin P1, P2, and then plugs the projection device into a power cord, the first circuit 106 can receive the firmware update command CMD1, so that the first circuit 106 outputs the power control signal VON from the second input-output pin P3 to the power converter 102, so as to control the power converter 102 to provide the second voltage V2 to the first circuit 106 for initial setting, as shown in process Sa. After the first circuit 106 completes the initial setting, the first circuit 106 can provide the first signal VD1 to the default pin PIN1 of the second circuit 108, so that the default pin PIN1 of the second circuit 108 can be set to the level of the first signal VD1 (low voltage logic level), as shown in process Sb. Then, as shown in process Sc, the first circuit 106 controls the switch unit 104 to conduct the power supply path between the power converter 102 and the second circuit 108, so that the switch unit 104 converts the first voltage V1 from the power converter 102 into a third voltage V3, and provides the third voltage V3 to the second circuit 108 to start the second circuit 108. After being started, the second circuit 108 may receive the first signal VD1 from the first circuit 106 and enter the firmware update mode, such as process Sd.

FIG3 is an operation timing diagram of a control circuit according to an embodiment of the present invention. Please refer to FIG1, FIG2, and FIG3 simultaneously. At time point t1, the first circuit 106 outputs a power control signal VON from the second input/output pin P3 to the power converter 102 to control the power converter 102 to provide the first voltage V1 to the switch unit 104, and control the power converter 102 to provide the second voltage V2 to the first circuit 106. As shown in FIG3 , the first circuit 106 is initialized during a period T1 corresponding to a time period t1-t2, so that the first signal VD1 generates a first level, wherein the first level may be, for example, a high voltage logic level during a time period t1-t2, thereby enabling the first circuit 106 to be initialized, and after the first circuit 106 completes the initialization, such as at time point t2, the first circuit 106 changes the first level to a second level, wherein the second level is, for example, a low voltage logic level, thereby enabling the default pin PIN1 of the second circuit 108 to enter a firmware update mode upon receiving the first signal VD1 corresponding to the second level.

Please continue to refer to Figure 3. After the first circuit 106 provides the first signal VD1 corresponding to the second level to the second circuit 108, the first circuit 106 can provide a switch control signal VSW to the switch unit 104 at time point t3 to control the switch unit 104 to turn on the power supply path between the power converter 102 and the second circuit 108, so that the switch unit 104 converts the first voltage V1 from the power converter 102 into a third voltage V3, and provides the third voltage V3 to the second circuit 108, thereby starting the second circuit 108. After being activated, the second circuit 108 can receive the first signal VD1 corresponding to the second level from the first circuit 106. For example, at time point t4, the default pin PIN1 of the second circuit 108 is set to the level of the first signal VD1 (low voltage logic level), and then the firmware update mode can be entered. The firmware update mode can be used, for example, to update the color, brightness, speaker parameters and light valve control settings of the projection device, but is not limited thereto.

In this way, the first signal VD1 is first provided to the default pin PIN1 of the second circuit 108, and then the switch unit 104 is controlled to convert the first voltage V1 into the third voltage V3 and provide it to the second circuit 108. This can effectively prevent the second circuit 108 from receiving the first signal VD1 of the default pin PIN1 too late and causing malfunction, thereby causing the system of the projection device to crash.

FIG4A is a flowchart of the startup of the microcontroller of the first circuit according to the embodiment of the present invention, and FIG4B is a flowchart of the startup of the second circuit according to the embodiment of the present invention. As shown in FIG4A, after receiving the second voltage V2 provided by the power converter 102, the microcontroller 110 of the first circuit 106 starts (Startup) as in step Sa-1. After startup, as in step Sa-2, the interrupt controller (Interrupt Controller) in the microcontroller 110 can make the microcontroller 110 still in the interrupt control state, and then enter step Sa-3 to make the microcontroller 110 enter the initial setting stage (U-Boot stage) and start initial setting. After the initial setting of the microcontroller 110 is completed, it can enter the operating system as in step Sa-4. The operating system is, for example, the Linux operating system. The microcontroller 110 of the first circuit 106 can provide the first signal VD1 to the default pin PIN1 of the second circuit 108 after executing the startup process shown in Figure 4A and completing the initial setting. At this time, the switch unit 104 has not yet provided the third voltage V3 to the second circuit 108, that is, the second circuit 108 has not yet started the startup process of Figure 4B. When the switch unit 104 provides the third voltage V3 to the second circuit 108, the second circuit 108 enters step Sb-1 to start (Startup). After startup, as in step Sb-2, it enters the basic input and output system (BIOS) to perform basic settings. Next, as in step Sb-3, it enters the boot stage mode (Bootloader). Since the first signal VD1 from the first circuit 106 has been provided to the default pin PIN1 of the second circuit 108, the second circuit 108 can receive the first signal VD1 the moment it operates, so it will not enter the operating system (Linux operating system) as in step Sb-4. That is, the second circuit 108 is set to the level corresponding to the first signal VD1 (low voltage logic level) in the boot phase mode (Bootloader) because the default pin PIN1 is received, so it can enter the firmware update mode. Please refer to Figure 3 again. When the second circuit 108 enters the boot phase mode (Bootloader) at time point t4, the default pin PIN1 of the second circuit 108 has been set to the level corresponding to the first signal VD1 (low voltage logic level). In this way, it can effectively avoid the second circuit 108 receiving the first signal VD1 of the default pin PIN1 too late and causing malfunction, thereby causing the system of the projection device to crash.

In addition, the above-mentioned embodiment only needs to use one microcontroller 110 to effectively ensure that the second circuit 108 is smoothly updated with firmware, thereby avoiding erroneous operation between the first circuit 106 and the second circuit 108 before the initial setting is completed, without the need to use multiple microcontrollers, thereby effectively reducing costs, and only by controlling the update process of the microcontroller 110 of the first circuit 106 without using other microcontrollers, the hardware and software design and control method can be simplified.

In addition, since the first circuit 106 of the above embodiment does not use the input/output pins that can be detected or controlled when power is supplied to the control circuit 100 but not activated (such as the first input/output pins P1, P2 and the second input/output pin P3) to make the second circuit 108 enter the firmware update mode when providing the first signal VD1 and providing the switch control signal VSW, the input/output pins that can be detected and controlled when power is supplied to the control circuit 100 but not activated can be reserved for other applications, such as infrared detection, Wi-Fi Wake up, control the behavior of the LED light in standby mode, or use a digital-analog key (ADC-KEY) in parallel with the reserved input and output pins to make the design of the control circuit 100 more flexible. The above applications are only examples and are not intended to limit the scope of application.

FIG5 is a flow chart of a control method of a control circuit according to an embodiment of the present invention, wherein the control circuit is applicable to a projection device, and the control circuit may include a power converter, a switch unit, a first circuit, and a second circuit, wherein the first circuit is coupled to the power converter, the second circuit, and the switch unit, the switch unit is coupled between the power converter and the second circuit, and the switch unit is used to turn on or off the power supply path between the power converter and the second circuit. From the above embodiment, it can be seen that the control method of the control circuit may at least include the following steps. First, the first circuit receives a firmware update instruction and controls the power converter to provide a first voltage to the switch unit according to the firmware update instruction, and the first circuit performs initial settings (step S502). After the first circuit completes the initial setting, the first circuit provides a first signal to the default pin of the second circuit (step S504). The level corresponding to the first signal can be, for example, a low voltage logic level, but is not limited thereto. After the first circuit provides the first signal to the second circuit, the first circuit controls the switch unit to conduct the power supply path between the power converter and the second circuit (step S506), so that the switch unit converts the first voltage from the power converter into a third voltage and provides it to the second circuit, so that the second circuit is activated. After the second circuit is activated, it receives the first signal from the first circuit and enters the firmware update mode (step S508).

In detail, the control method of the control circuit can be shown in FIG6. FIG6 is a detailed flow chart of a control method of the control circuit according to an embodiment of the present invention. Please refer to FIG6 and FIG1, after the power button and the menu button of the projection device are pressed, the projection device is plugged into the power cord so that power is provided to the control circuit 100, and then the first circuit 106 receives the firmware update command CMD1 and controls the power converter 102 to provide the startup voltage VSBY to the microcontroller 110, so that the microcontroller 110 starts to operate (such as step S1). Specifically, after at least one button corresponding to the first input/output pins P1 and P2 (e.g., a power button and a menu button) is pressed, the projection device is plugged into a power cord, so that power is provided to the control circuit 100, and the first circuit 106 receives the firmware update command CMD1, and the power converter 102 provides the startup voltage VSBY to the microcontroller 110.

Then, as in step S2, the microcontroller 110 outputs a power control signal VON to the power converter 102 from the second input/output pin P3 according to the pre-set command by the configuration personnel, so as to start the power converter 102, so that the power converter 102 provides the first voltage V1 to the switch unit 104 (as in step S3), and the first circuit 106 performs initialization (step S4). Furthermore, the first circuit 106 can also control the power converter 102 to provide the second voltage V2, and the first circuit 106 performs initialization when receiving the second voltage V2 from the power converter 102. After the first circuit 106 completes the initial setting, according to the instructions preset by the configuration personnel, the first circuit 106 provides the first signal VD1 to the default pin PIN1 of the second circuit 108 (step S5).

After providing the first signal VD1 to the second circuit 108, the first circuit 106 may provide a switch control signal VSW to the switch unit 104 (step S6) according to the instructions pre-set by the configuration personnel, so as to control the switch unit 104 to turn on the power supply path between the power converter 102 and the second circuit 108, so that the switch unit 104 converts the first voltage V1 from the power converter 102 into a third voltage V3, and provides the third voltage V3 to the second circuit 108, so that the second circuit 108 obtains the third voltage V3 (step S7). After the second circuit 108 obtains the third voltage V3, the second circuit 108 receives the first signal VD1 on the default pin PIN1, so that the default pin PIN1 of the second circuit 108 is set to the level of the first signal VD1 (low voltage logic level) (step S8), and the second circuit 108 enters the firmware update mode to perform the firmware update (step S9). Further, the first circuit 106 can generate a first level for the first signal VD1 when starting the initial setting, and change the first level to a second level after the first circuit 106 completes the initial setting, so that the default pin PIN1 of the second circuit 108 enters the firmware update mode when receiving the first signal VD1 corresponding to the second level.

In summary, after providing the first signal to the preset pin of the second circuit, the first circuit of the embodiment of the present invention can control the switch unit to provide the first voltage from the power converter to the second circuit, so as to activate the second circuit to respond to the first signal and enter the firmware update mode. This can effectively prevent the second circuit from receiving the first signal of the preset pin too late and causing erroneous operation, thereby causing the system of the projection device to crash. In addition, since the first circuit does not use the input/output pins (such as the first input/output pins P1, P2 and the second input/output pin P3) that can only be detected or controlled when power is supplied to the control circuit but not activated to enable the second circuit to enter the firmware update mode when providing the first signal VD1 and providing the switch control signal VSW, the input/output pins that can be detected and controlled when power is supplied to the control circuit but not activated can be reserved for other applications, thereby making the design of the control circuit 100 more flexible.

However, the above is only the preferred embodiment of the present invention, and it should not be used to limit the scope of the implementation of the present invention. That is, all simple equivalent changes and modifications made according to the scope of the patent application and the content of the invention description are still within the scope of the present invention. In addition, any embodiment or patent application of the present invention does not need to achieve all the purposes, advantages or features disclosed by the present invention. In addition, the abstract and title are only used to assist in searching for patent documents, and are not used to limit the scope of the rights of the present invention. Furthermore, the first, second, etc. mentioned in the specification are only used to indicate the names of the components, and are not used to limit the upper or lower limits on the number of components.

100: control circuit 102: power converter 104: switch unit 106: first circuit 108: second circuit 110: microcontroller P1~P5: input and output pins PIN1: default pin CMD1: firmware update command V1: first voltage V2: second voltage V3: third voltage VSBY: start voltage VON: power control signal VD1: signal VSW: switch control signal t1~t4: time point S502~S508, S1~S9: control method steps of control circuit Sa~Sd: process Sa-1~Sa-4, Sb-1~Sb-4: steps.

FIG. 1 is a schematic diagram of a control circuit according to an embodiment of the present invention. FIG. 2 is a schematic diagram of a working sequence of a control circuit according to an embodiment of the present invention. FIG. 3 is an operation timing diagram of a control circuit according to an embodiment of the present invention. FIG. 4A is a startup flowchart of a microcontroller of a first circuit according to an embodiment of the present invention. FIG. 4B is a startup flowchart of a second circuit according to an embodiment of the present invention. FIG. 5 is a flowchart of a control method of a control circuit according to an embodiment of the present invention. FIG. 6 is a detailed flowchart of a control method of a control circuit according to an embodiment of the present invention.

100: Control circuit

102: Power converter

104: Switch unit

106: First circuit

108: Second circuit

110: Microcontroller

P1~P5: Input and output pins

PIN1: default pin

CMD1: Firmware update command

V1: first voltage

V2: Second voltage

V3: The third voltage

VSBY: Startup voltage

VON: power control signal

VD1:Signal

VSW: switch control signal

Claims (14)

A control circuit includes a power converter, a switch unit, a first circuit and a second circuit, wherein: The first circuit is coupled to the power converter, the second circuit and the switch unit; The switch unit is coupled between the power converter and the second circuit to turn on or off the power supply path between the power converter and the second circuit; The first circuit is suitable for receiving a firmware update instruction and controlling the power converter to provide a first voltage to the switch unit according to the firmware update instruction, and the first circuit performs an initial setting; After completing the initial setting, the first circuit provides a first signal to a preset pin of the second circuit; and After the first circuit provides the first signal to the second circuit, the first circuit controls the switch unit to conduct the power supply path between the power converter and the second circuit, so that the switch unit converts the first voltage from the power converter into a third voltage and provides it to the second circuit, so that the second circuit is started. After the second circuit is started, it receives the first signal from the first circuit and enters a firmware update mode. A control circuit as described in claim 1, wherein the first circuit receives a second voltage from the power converter to perform the initial setting, and the first circuit provides the first signal after completing the initial setting. A control circuit as described in claim 2, wherein the first circuit includes a microcontroller, at least one first input-output pin and a second input-output pin, and after a key corresponding to the at least one first input-output pin is pressed, the control circuit receives an external power supply and enters a standby mode. In response to the control circuit entering the standby mode, the first circuit receives the firmware update instruction, and the power converter provides a start voltage to the microcontroller. The microcontroller outputs a power control signal to the power converter from the second input-output pin to control the power converter to provide the first voltage and the second voltage. In response to the first circuit receiving the second voltage, the control circuit enters an operating mode. A control circuit as described in claim 3, wherein the first circuit further includes a third input-output pin and a fourth input-output pin, the third input-output pin is coupled to the switch unit, and the fourth input-output pin is coupled to the default pin, wherein in the standby mode, the at least one first input-output pin and the second input-output pin can be detected and controlled, and in the working mode, the third input-output pin and the fourth input-output pin can be detected or controlled. A control circuit as described in claim 1, wherein the first circuit is a display control single chip and the second circuit is a digital optical processing chip. A control circuit as described in claim 1, wherein the first signal generates a first level when the first circuit starts the initial setting, and changes the first level to a second level after the first circuit completes the initial setting, so that the default pin of the second circuit enters the firmware update mode when receiving the first signal corresponding to the second level. A control circuit as described in claim 1, wherein after the first circuit provides the first signal to the second circuit, the first circuit provides a switch control signal to the switch unit, so that the switch unit turns on the power supply path between the power converter and the second circuit. A control method for a control circuit, the control circuit includes a power converter, a switch unit, a first circuit and a second circuit, wherein the first circuit is coupled to the power converter, the second circuit and the switch unit, and the switch unit is coupled between the power converter and the second circuit to turn on or off the power supply path between the power converter and the second circuit. The control method includes: The first circuit is suitable for receiving a firmware update instruction and controlling the power converter to provide a first voltage to the switch unit according to the firmware update instruction, and the first circuit performs an initial setting; After the first circuit completes the initial setting, a first signal is provided to a preset pin of the second circuit; After the first circuit provides the first signal to the second circuit, the first circuit controls the switch unit to conduct the power supply path between the power converter and the second circuit; and causes the switch unit to convert the first voltage from the power converter into a third voltage and provide it to the second circuit, so that the second circuit is started. After the second circuit is started, it receives the first signal from the first circuit and enters a firmware update mode. The control method as described in claim 8 further includes: The first circuit receives a second voltage from the power converter to perform the initial setting, and provides the first signal after completing the initial setting. The control method as described in claim 9, wherein the first circuit includes a microcontroller, at least one first input/output pin and a second input/output pin, and the control method further includes: After the key corresponding to the at least one first input/output pin is pressed, the control circuit receives an external power supply and enters a standby mode, in response to the control circuit entering the standby mode, the first circuit receives the firmware update instruction, and the power converter provides a startup voltage to the microcontroller; and The microcontroller outputs a power control signal from the second input/output pin to the power converter to control the power converter to provide the first voltage and the second voltage, and in response to the first circuit receiving the second voltage, the control circuit enters an operating mode. A control method as described in claim 10, wherein the first circuit further includes a third input-output pin and a fourth input-output pin, the third input-output pin is coupled to the switch unit, and the fourth input-output pin is coupled to the default pin, wherein in the standby mode, the at least one first input-output pin and the second input-output pin can be detected and controlled, and in the working mode, the third input-output pin and the fourth input-output pin can be detected or controlled. A control method as described in claim 8, wherein the first circuit is a display control single chip and the second circuit is a digital optical processing chip. The control method as described in claim 8, wherein the control method comprises: Controlling the first circuit to generate a first level when the first signal starts the initial setting, and changing the first level to a second level after the first circuit completes the initial setting, so that the default pin of the second circuit enters the firmware update mode when receiving the first signal corresponding to the second level. A control method as described in claim 8, wherein after the first circuit provides the first signal to the second circuit, the first circuit provides a switch control signal to the switch unit, so that the switch unit turns on the power supply path between the power converter and the second circuit.

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