TWI775702B - Control circuit and in-system programming method thereof - Google Patents

Abstract

A control circuit is provided. The control circuit is disposed in a first electronic device, and the first electronic device is electrically connected to a second electronic device through an HDMI (High-Definition Multimedia Interface) bus. The control circuit includes: a flash memory comprising an application region and an in-system programming (ISP) region; and a computation unit. When the first electronic device has received an HDMI-CEC (Consumer Electronic Control) command, the computation unit determines whether the HDMI-CEC command satisfies a specific condition. In response to the HDMI-CEC command satisfying the specific condition, the control circuit controls the first electronic device to enter an in-system programming mode to update firmware in the application region or the ISP region.

Description

Control circuit and system programming method thereof

The present invention relates to a control circuit, and more particularly, to a control circuit and an in-system programming (ISP) method thereof.

The Consumer Electronics Control (CEC) protocol is one of the functions of the High-Definition Multimedia Interface (HDMI) standard, which uses a single-wire bidirectional serial interface for data transmission to facilitate the control and detection of the High-Definition Multimedia Interface (HDMI). Any AV device on the HDMI) network, designed to reduce the number of remote controls and the number of button presses the user has to make. The Consumer Electronic Control Agreement has defined basic functions, but designers interpret differences, allow flexibility of custom messages, and do not require compliance with the CEC (Compliance Test Specification) test. There has always been a problem of commonality between different brands.

In addition, the CEC agreement does not specify the system programming (ISP) update command and process. If any device in the audio-visual system needs to be updated with firmware, the device needs to add an additional communication interface (eg, UART or USB interface), which increases the cost of the device and the probability of static electricity damage.

In view of this, the present invention provides a control circuit and an in-system programming method thereof to solve the above problems.

The present invention provides a control circuit, which is arranged in a first electronic device, and the first electronic device is electrically connected with a second electronic device through a high-definition multimedia interface (HDMI) bus bar. The control circuit includes: a flash memory, wherein the flash memory includes an application program area and a system programming area; and an operation unit. When the first electronic device receives a high-definition multimedia interface-consumer electronics control (HDMI-CEC) command, the computing unit determines whether the HDMI-CEC command meets a specific condition. In response to the HDMI-CEC command meeting the specific condition, the control circuit controls the first electronic device to enter a system programming mode to update the firmware in the application area or the system programming area.

In some embodiments, the logical address of the HDMI-CEC command corresponds to the first electronic device, the first electronic device is a CEC slave device, and the second electronic device is a CEC master device.

In some embodiments, the specific condition indicates that the HDMI-CEC command carries system programming commands or data of a specific manufacturer, or the HDMI-CEC command carries system programming commands or data of a specific manufacturer of a manufacturer identifier.

In some embodiments, after the first electronic device enters the system programming mode, the control circuit further determines whether a reset command is received. In response to the control circuit judging that the reset command is received, the control circuit clears the reset state of the first electronic device, closes the system programming mode, and selects from the application area or the system according to the system programming command Start the programming area.

In some embodiments, after the control circuit selects to boot from the application program area or the system programming area according to the system programming command, the control circuit further generates a system reset request signal to reset the first electronic device, And the code is obtained from the application program area or the system programming area updated by the system programming instruction for booting.

The present invention further provides a system programming method for a first electronic device, the first electronic device is electrically connected to a second electronic device through a high-definition multimedia interface (HDMI) bus, and the first electronic device It includes a flash memory and a control circuit element, and the flash memory includes an application program area and a system program area. The method includes the following steps: when the first electronic device receives a high-definition multimedia interface-consumer electronics control (HDMI-CEC) command, using the control circuit to determine whether the HDMI-CEC command meets a specific condition; and In response to the HDMI-CEC command meeting the specific condition, the control circuit is used to control the first electronic device to enter a system programming mode to update the firmware in the application area or the system programming area.

In some embodiments, the logical address of the HDMI-CEC command corresponds to the first electronic device, the first electronic device is a CEC slave device, and the second electronic device is a CEC master device.

In some embodiments, the specific condition indicates that the HDMI-CEC command carries system programming commands or data of a specific manufacturer, or the HDMI-CEC command carries system programming commands or data of a specific manufacturer of a manufacturer identifier.

In some embodiments, after the first electronic device enters the system programming mode, the method further includes: using the control circuit to determine whether a reset command is received; and determining that the reset command is received according to the control circuit , use the control circuit to clear the reset state of the first electronic device, close the system programming mode, and select to boot from the application program area or the system programming area according to the system programming command.

In some embodiments, after the control circuit selects to boot from the application program area or the system programming area according to the system programming command, the method further includes: using the control circuit to generate a system reset request signal to reset the system the first electronic device, and obtains the code from the application program area or the system programming area updated by the system programming instruction for booting.

In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, a preferred embodiment is exemplified below, and is described in detail as follows in conjunction with the accompanying drawings.

It must be understood that words such as "comprising" and "including" used in this specification are used to indicate the existence of specific technical features, values, method steps, operation processes, elements and/or components, but do not exclude the possibility of Plus more technical features, values, method steps, job processes, elements, components, or any combination of the above.

FIG. 1A is a block diagram of an electronic system according to an embodiment of the present invention.

The electronic system 10 includes electronic devices 100A to 100E, wherein the electronic devices 100A to 100E may be, for example, audio-visual equipment with a High Definition Multimedia Interface (HDMI), and all support consumer electronic control (CEC). ) function, wherein the above-mentioned audio and video equipment may include, but not be limited to, set-top boxes, DVD players, Blu-ray players, personal computers, game consoles, integrated amplifiers, digital audio, digital TVs, TV sticks, and the like. For convenience of description, the electronic devices 100A to 100E are respectively a high-definition television (HDTV), a gaming console (gaming console), an audio/video receiver, a DVD player, and a satellite receiver (satellite receiver).

The electronic devices 100B to 100E, for example, can be electrically connected to the electronic device 100A directly or indirectly (eg, in a daisy chain manner) through individual HDMI interfaces. For example, electronic device 100A includes HDMI interfaces 121 and 122 , electronic device 100B includes HDMI interface 41 , electronic device 100C includes HDMI interfaces 42 to 44 , electronic device 100D includes HDMI interface 45 , and electronic device 100E includes HDMI interface 46 . The electronic devices 100A and 100B can be connected by, for example, an HDMI cable 51 , the electronic devices 100A and 100C can be connected by, for example, an HDMI cable 52 , the electronic devices 100C and 100D can be connected by, for example, an HDMI cable 53 , and the electronic devices 100C and 100E For example, the connection can be made via the HDMI cable 54 . In addition, the electronic device 100A further includes a network interface 123 for connecting to the network 20 , wherein the network interface 123 can be, for example, a wired network interface or a wireless network interface. For example, the electronic device 100A can be connected to other personal computers or servers on the network 20 through the network interface 123 .

It should be noted that, through the connection method shown in FIG. 1A, the electronic devices 100A to 100E are all located on the HDMI-CEC bus, and the remote control 30 of the electronic device 100A can not only control the electronic device 100A, but also transmit HDMI-CEC The electronic devices 100B to 100E are controlled by commands and through the HDMI-CEC bus. In addition, the above-mentioned HDMI-CEC command may be not only a standard command regulated by the HDMI 1.3a agreement, but also a vendor specific command.

FIG. 1B is a block diagram of the electronic device 100A according to the embodiment of FIG. 1A of the present invention. Please refer to both Figure 1A and Figure 1B.

The electronic device 100A includes a control circuit 110 , HDMI interfaces 121 and 122 , a network interface 123 and an infrared receiver 124 . The HDMI interfaces 121 and 122 are connected to the electronic devices 100B and 100C, respectively. The network interface 123 is connected to the network 20 . The infrared receiver 124 can receive the infrared signal from the remote controller 30 and decode the infrared signal to obtain the corresponding control command.

The control circuit 110 can be implemented by, for example, an integrated circuit (integrated circuit), a system-on-chip (SOC) or other logic circuits having the same function, but the invention is not limited thereto. The control circuit 110 includes a processing unit 111 , a flash memory 112 and a volatile memory 113 . The processing unit 111 can be, for example, a central processing unit (CPU), a digital signal processor (DSP), or a microcontroller (MCU), but the invention is not limited thereto. The volatile memory 113 can be, for example, a static random access memory (SRAM), which can be used as temporary storage data for the processing unit 111 to perform operations, but the invention is not limited thereto.

The flash memory 112 can be divided into an application area 1121 , a system programming area 1122 and a data area 1123 . The application program area 1121 is used for storing one or more application programs for the processing unit 111 to execute. The system programming area 1122 is used to store the firmware of the bootloader. The system programming area 1122 may also be called a boot program area. In some embodiments, the application area 1121 and the system programming area 1122 can be set as read only memory (ROM) according to the security configuration of the flash memory 112, so the application area 1121 and the system programming area 1122 can also be They are respectively called Application Program ROM (APROM) and System Programming Loader Read-Only Memory (ISP Loader ROM, LDROM). The data area 1123 is used for storing data, and the data area 1123 may also be called a data flash memory. In some embodiments, the application program area 1121 , the system programming area 1122 and the data area 1123 can also be implemented by different flash memories. In this embodiment, the electronic devices 100B to 100E each include an arithmetic element similar to the control circuit 110 and a non-volatile memory similar to the flash memory 112 for performing the ISP update procedure.

Taking the HDMI 1.3a protocol as an example, the value of the opcode (opcode) for a specific vendor command can include 0x8C, 0x89, etc., where 0x8C represents the device vendor ID (Device Vendor ID) and its parameter is the vendor ID (Vendor ID). ), 0x89 means Vendor Command and its parameter is Vendor Specific Data.

In one embodiment, each of the electronic devices 100A- 100E in the electronic system 10 has individual physical addresses and logical addresses, wherein the electronic device 100A is regarded as a CEC master device ( master device), the electronic devices 100B to 100E are regarded as CEC slave devices. For example, assuming that the physical address of the electronic device 100A is 0.0.0.0 and the physical addresses of the extended display identification data (EDID) of the HDMI interfaces 121 and 122 are 1.0.0.0 and 2.0.0.0, respectively, The physical addresses of the electronic device 100B and the electronic device 100C are also 1.0.0.0 and 2.0.0.0, respectively. Because the electronic devices 100D and 100E are connected to the electronic device 100C, the physical addresses of the electronic devices 100D and 100E may be 2.1.0.0 and 2.2.0.0, respectively. In addition, the logical address of the electronic device 100A is 0, and the logical addresses of the electronic devices 100B, 100C, 100D, and 100E are 1, 2, 3, and 4, respectively.

When the control circuit 110 receives a specific HDMI-CEC command including the ISP command from the infrared receiver 124 or the network interface 123, the control circuit 110 can execute the specific HDMI-CEC command on the host device according to the logical address in the specific HDMI-CEC command. The ISP command, or the ISP command is transmitted to the corresponding CEC slave device, and the control circuit of the CEC slave device performs a system programming procedure to update the firmware.

For example, if the logical address in the HDMI-CEC command received by the control circuit 110 is 0, and the parameter of the opcode 0x89 in the HDMI-CEC command carries the ISP command or data of a specific manufacturer, or the HDMI-CEC command The CEC command carries a specific manufacturer's ISP command or data (eg, opcode 0x89) with a manufacturer identifier (eg, opcode 0x8C), and the control circuit 110 controls the electronic device 100A to enter the ISP mode.

If the logical address in the HDMI-CEC command received by the control circuit 110 is 0, and the parameter of the opcode 0x89 in the HDMI-CEC command does not contain the ISP command or data of a specific manufacturer, the control circuit 110 will clear the electronic The reset status of the device 100A, and the ISP mode is turned off and the system is set to boot from the application area 1121 (APROM). Next, the control circuit 110 generates a system reset signal to reset the electronic device 100A, and reads the code from the application program area 1121 (APROM) to perform the booting process of the electronic device 100A.

If the logical address in the HDMI-CEC command received by the control circuit 110 is not 0, it means that the HDMI-CEC command is sent to a specific CEC slave device in the electronic system 10 (eg, the electronic devices 100B-100E). For example, when the logical address in the HDMI-CEC command received by the control circuit 110 is 3, it means that the HDMI-CEC command is sent to a specific electronic device in the electronic system 10 (eg, the electronic device 100D). At this time, the control circuit 110 will first re-initialize the HDMI interface of the specific CEC slave device, and then transmit the HDMI-CEC command to the corresponding specific CEC slave device. When the CEC slave device has completely stored the HDMI-CEC commands in the command buffer (eg, volatile memory) of the specific CEC slave device, the control circuit in the specific CEC slave device can interpret the HDMI-CEC commands, and Execute the ISP command in the HDMI-CEC command.

2A-2B are flowcharts of a system programming method according to an embodiment of the present invention. Please also refer to Figures 1A-1B and Figures 2A-2B.

In step S202, it is determined whether the HDMI-CEC command conforms to a specific ISP command. If the HDMI-CEC command conforms to the specific ISP command, step S204 is executed. If the HDMI-CEC command does not conform to the specific ISP command, step S206 is executed. For example, the above-mentioned specific ISP command, for example, indicates that the parameter of the opcode 0x89 in the HDMI-CEC command has the ISP command or data of a specific manufacturer, or the HDMI-CEC command has a specific manufacturer identifier (such as the opcode 0x8C) Manufacturer's ISP command or data (eg opcode 0x89).

In step S204, enter the application program area and execute the corresponding CEC command flow. For example, if the logical address of the HDMI-CEC command is not 0, it means that the HDMI-CEC command is for a specific CEC slave device, such as one of the electronic devices 100B to 100E. Therefore, the control circuit 110 of the electronic device 100A and/or the control circuit of the specific CEC slave device can re-initialize the HDMI interface of the specific CEC slave device to facilitate the specific CEC slave device to receive ISP mode commands and update data.

In step S206, the reset state is cleared. For example, when each electronic device in the electronic system 10 is powered on and enters the boot process, each electronic device will be in a reset state, and the reset state will not be cleared until the control circuit of each electronic device determines whether to enter the ISP mode. For example, set the signal RSTSRC[1:0] to 2'b11 (Note: binary value).

In step S208, the ISP mode is turned on and the boot from the boot program area is selected. For example, because the control circuit in each electronic device includes an application program area (APROM) 1121 and a system programming area (LDROM) 1122, and the control circuit needs to choose to boot from the application program area 1121 or the system programming area 1122. For example, the control circuit of a specific CEC slave device may set the signal ISPCON[1:0] to 2'b10 to select boot from the system programming area 1122 (ie, the boot program area).

In step S210, a system reset request signal is generated. For example, after steps S206 and S208 are completed, the control circuit of the specific CEC slave device can generate a system reset request signal (SYSRESETREQ) to reset the specific CEC slave device, for example, the signal AIRCR[2] can be set to 1.

In step S212, the HDMI interface of the specific CEC slave device is re-initialized.

In step S214, it is determined whether to enter the ISP mode. If it is determined to enter the ISP mode, step S216 is executed. If it is determined that the ISP mode is not entered, step S220 is executed.

In step S216, the ISP command is read from the CEC slave device.

In step S218, the ISP command is interpreted. For example, after the control circuit of a specific CEC slave device successfully obtains the ISP command from the buffer, the control circuit can interpret the ISP command to know the operation to be performed by the ISP command.

In step S220, the reset state is cleared. For example, the specific CEC slave device is in a reset state because the specific CEC slave device has received the reset signal to re-execute the boot procedure. Therefore, the control circuit of the specific CEC slave device and then clears the reset state of the specific CEC slave device, eg, sets the signal RSTSRC[1:0] to 2'b11 (note: binary value).

In step S222, the ISP function is turned off and the booting from the application area is selected. For example, because the control circuit in each electronic device includes an application program area (APROM) and a system programming area (LDROM), and the control circuit needs to choose to boot from the application program area or the system programming area. For example, the control circuit of the CEC slave device may set signals ISPCON[1:0] to 2'b00 to select boot from application area 1121.

In step S224, a system reset request signal is generated. For example, the control circuit of a specific CEC slave device can generate a system reset request signal (SYSRESETREQ) to reset the specific CEC slave device, for example, the signal AIRCR[2] can be set to 1.

In step S226, the control circuit of the specific CEC slave device determines whether a reset command is received. If the control circuit of the specific CEC slave device determines that the reset command is received, step S230 is executed. If the control circuit of the specific CEC slave device determines that the reset command has not been received, step S228 is executed.

In step S228, the corresponding operations in the ISP command are executed. For example, a specific CEC slave device can enter ISP mode according to a specific manufacturer command (such as opcode 0x89) in the HDMI-CEC command to update the firmware, where the new firmware is stored in the buffer of the specific CEC slave device. ISP information. It should be noted that the above firmware update operation can update the new firmware to the application area or the system programming area, depending on the ISP command in the HDMI-CEC command.

In step S230, the reset state is cleared. For example, the specific CEC slave device is in a reset state because the specific CEC slave device has received the reset signal to re-execute the boot process. Therefore, the control circuit of the specific CEC slave device and then clears the reset state of the specific CEC slave device, eg, sets the signal RSTSRC[1:0] to 2'b11 (note: binary value).

In step S232, the ISP function is turned off and the booting from the application area is selected. For example, because the control circuit in each electronic device includes an application program area (APROM) and a system programming area (LDROM), and the control circuit needs to choose to boot from the application program area or the system programming area. For example, the control circuit of the CEC slave device may set signals ISPCON[1:0] to 2'b00 to select boot from application area 1121.

In step S234, a system reset request signal is generated. For example, the control circuit of a specific CEC slave device can generate a system reset request signal (SYSRESETREQ) to reset the specific CEC slave device, for example, the signal AIRCR[2] can be set to 1.

Although the flow in Figures 2A-2B is mainly based on a specific CEC slave device, the CEC master device (eg electronic device 100A) also applies the flow in Figures 2A-2B, the difference lies in the logic bits in the HDMI-CEC command When the address is 0, the above process can be performed by the CEC master control device.

In summary, the present invention provides a control circuit and a system programming method thereof, which can utilize the HDMI-CEC protocol to enable one or more electronic devices in an electronic system to execute a system programming program for firmware update, and execute the above The system programming process only needs to change the specific commands/opcodes in the HDMI-CEC protocol, without adding additional cables/interfaces and modifying the hardware layout, and will not affect the existing electrical characteristics of the electronic device.

The use of words such as "first", "second" and "third" in the scope of the patent application is used to modify the elements in the scope of the patent application, and is not used to indicate that there is a priority order, an antecedent relationship, or a The precedence of one element over another, or the chronological order in which method steps are performed, is only used to distinguish elements with the same name.

Although the present invention is disclosed above with preferred embodiments, it is not intended to limit the scope of the present invention. Anyone with ordinary knowledge in the technical field can make some changes and modifications without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the appended patent application.

10: Electronic Systems 20: Internet 30: Remote control 41~46: HDMI interface 51~54: HDMI cable 100A~100E: Electronic device 110: Control circuit 111: Processing unit 112: Flash memory 113: volatile memory 121~122: HDMI interface 123: Web Interface 124: Infrared receiver 1121: Application area 1122: System programming area 1123: Data area S202~S234: Steps

FIG. 1A is a block diagram of an electronic system according to an embodiment of the present invention. FIG. 1B is a block diagram of the electronic device 100A according to the embodiment of FIG. 1A of the present invention. 2A-2B are flowcharts of a system programming method according to an embodiment of the present invention.

10: Electronic Systems

20: Internet

30: Remote control

41~46: HDMI interface

51~54: HDMI cable

100A~100E: Electronic device

121~122: HDMI interface

123: Web Interface

Claims (10)

A control circuit is provided in a first electronic device, the first electronic device is electrically connected with a second electronic device through a high-definition multimedia interface (HDMI) bus bar, and the control circuit comprises: a flash memory, wherein the flash memory includes an application area and a system programming area; and an arithmetic unit; Wherein, when the first electronic device receives a high-definition multimedia interface-consumer electronics control (HDMI-CEC) command, the computing unit determines whether the HDMI-CEC command meets a specific condition; Wherein, in response to the HDMI-CEC command meeting the specific condition, the control circuit controls the first electronic device to enter a system programming mode to update the firmware in the application area or the system programming area. The control circuit of claim 1, wherein the logical address of the HDMI-CEC command corresponds to the first electronic device, the first electronic device is a CEC slave device, and the second electronic device is a CEC master device . The control circuit of claim 1, wherein the specific condition indicates that the HDMI-CEC command carries a system programming command or data of a specific manufacturer, or the HDMI-CEC command carries a system programming command or data of a specific manufacturer of a manufacturer identifier . The control circuit of claim 3, wherein after the first electronic device enters the system programming mode, the control circuit further determines whether a reset command is received, In response to the control circuit judging that the reset command is received, the control circuit clears the reset state of the first electronic device, closes the system programming mode, and selects the application program area or the system programming command according to the system programming command. Start the system programming area. The control circuit of claim 4, wherein after the control circuit selects to boot from the application area or the system programming area according to the system programming command, the control circuit further generates a system reset request signal to reset the first the electronic device, and obtains the code from the application program area or the system programming area updated by the system programming instruction for booting. A system programming method for a first electronic device, the first electronic device is electrically connected to a second electronic device through a high-definition multimedia interface (HDMI) bus, and the first electronic device includes a flash Memory and a control circuit element, and the flash memory includes an application program area and a system programming area, and the method includes: When the first electronic device receives a high-definition multimedia interface-consumer electronics control (HDMI-CEC) command, use the control circuit to determine whether the HDMI-CEC command meets a specific condition; and In response to the HDMI-CEC command meeting the specific condition, the control circuit is used to control the first electronic device to enter a system programming mode to update the firmware in the application area or the system programming area. The system programming method of claim 6, wherein the logical address of the HDMI-CEC command corresponds to the first electronic device, the first electronic device is a CEC slave device, and the second electronic device is a CEC master device. The system programming method of claim 6, wherein the specific condition means that the HDMI-CEC command carries a system programming command or data of a specific manufacturer, or the HDMI-CEC command carries a system programming command of a specific manufacturer with a manufacturer identifier, or material. The system programming method of claim 8, wherein after the first electronic device enters the system programming mode, the method further comprises: Using the control circuit to determine whether a reset command is received; and In response to the control circuit judging that the reset command is received, use the control circuit to clear the reset state of the first electronic device, close the system programming mode, and select from the application area or the system according to the system programming command Start the programming area. The system programming method of claim 9, wherein after the control circuit selects to boot from the application program area or the system programming area according to the system programming instruction, the method further comprises: The control circuit is used to generate a system reset request signal to reset the first electronic device, and to obtain code from the application program area or the system programming area updated by the system programming instruction for booting.

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