Display method and electronic device
Patent Information
- Application Number
- PCT/CN2025/078849
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2025-02-24
- Publication Date
- 2026-08-27
Smart Images
Figure CN2025078849_27082026_PF_FP_ABST
Abstract
Description
Display methods and electronic devices Technical Field
[0001] This application relates to the field of displays, and more particularly to a display method and an electronic device. Background Technology
[0002] Some displays use display driver integrated circuits (DDICs) that support RAMless video mode to reduce power consumption. In RAMless video mode, the DDIC cannot self-refresh the image data. Instead, the display processing unit (DPU) in the system-on-chip (SoC) needs to send image data to the DDIC periodically according to the display's refresh rate to drive the display panel for display.
[0003] However, for those based on In electronic devices with operating systems, the DPU in the SOC enters a doze state during the doze-suspend mode, preventing the DPU from sending image data to the display's DDIC and thus preventing the electronic device from displaying images. Summary of the Invention
[0004] This application provides a display method and an electronic device for displaying images in a sleep / suspend mode.
[0005] To achieve the above objectives, the embodiments of this application adopt the following technical solutions:
[0006] In a first aspect, a display method is provided, applied to an electronic device. The electronic device includes a system-on-a-chip (SoC) and a display screen. The SoC includes a central processing unit (CPU), a graphics processing unit (GPU), a digital processing unit (DPU), and a host frame buffer. The display screen includes a display driver integrated circuit (DDIC). If the display screen does not have a local frame buffer, the method includes: when the power mode of the electronic device is a first power mode, the CPU, GPU, and DPU remain powered on to display an image on the display screen, wherein the first power mode is a screen-on mode; upon receiving a first user operation, or if no user touch operation is received within a preset time, the power mode of the electronic device switches from the first power mode to a second power mode, wherein the second power mode is a sleep mode; when the power mode of the electronic device is the second power mode, the CPU, GPU, and DPU remain powered on to display an image on the display screen; in response to no user touch operation being received within the preset time, the power mode of the electronic device switches from the second power mode to a third power mode, wherein the third power mode is a sleep / suspend mode; when the power mode of the electronic device is the third power mode, the CPU and GPU remain powered off, and the DPU remains powered on to display an image on the display screen.
[0007] The display method provided in this application embodiment, in sleep / suspend mode, although the CPU and GPU are powered down to enter sleep state, the DPU remains powered on. The DPU can still read image data from the host frame buffer and drive the display screen to display the image. This enables the electronic device to still display images in sleep / suspend mode.
[0008] In one possible implementation, when the power mode of the electronic device switches from a first power mode to a second power mode, the electronic device enters a local always-on display (AOD) mode, a global AOD mode, or a smart table setting mode.
[0009] At this time, the CPU, GPU, and DPU are all powered on, enabling the electronic device to support AOD and smart table setting functions in the second power mode.
[0010] In one possible implementation, when the power mode of the electronic device switches from the second power mode to the third power mode, the electronic device remains in a local AOD mode, a global AOD mode, or a smart placement mode.
[0011] At this time, although the CPU and GPU are both powered down to reduce the power consumption of electronic devices, the DPU remains powered on and can still send image data to the DDIC, thereby driving the display screen to show images. This enables electronic devices to support AOD and smart table setting functions in the third power mode.
[0012] In one possible implementation, the method further includes reducing the brightness or grayscale of the display screen when the electronic device is in always-on display (AOD) mode.
[0013] In a global AOD (Ambient Light Distance) scenario, power consumption of electronic devices can be reduced by decreasing the brightness or grayscale of the display. Specifically, the DPU (Display Processing Unit) can reduce the display brightness by sending backlight commands to the DDIC (Display Controller Interface), and the DPU can reduce the display grayscale through local tone mapping (LTM).
[0014] In one possible implementation, when the CPU and GPU are both powered down and the DPU is powered on to display an image on the screen, the DDIC operates in a RAM-free video mode.
[0015] At this point, the display is an adaptive refresh display that supports a RAM-free video mode, which reduces the power consumption of electronic devices by lowering the display's refresh rate.
[0016] In one possible implementation, the method further includes: when the power mode of the electronic device is the third power mode, if the working mode of the DDIC is not the no-RAM video mode, then the CPU resources corresponding to the display screen are turned off; the CPU resources corresponding to the display screen include the CPU's display thread and interrupt event thread, the display thread is used by the CPU to transmit image data to the DDIC through the DPU, and the interrupt event thread is used by the CPU to process interrupt events fed back by the DPU.
[0017] Interrupt events include interrupts instructing the DPU to complete sending image data, and TE signals sent from the DDIC to the DPU. After shutting down the CPU's display thread, the CPU will no longer transmit image data to the DDIC via the DPU, and the CPU can then prepare to enter sleep mode. Similarly, after shutting down the CPU's interrupt event thread, the CPU will no longer respond to interrupt events from the DDIC, and the CPU can then prepare to enter sleep mode. Additionally, if there are interrupt events from the DPU that need to be processed, the CPU's display thread will be shut down only after the interrupt event has been processed.
[0018] In one possible implementation, there are multiple displays, and the method further includes: if the CPU resources corresponding to all displays are turned off, then the DPU is powered down.
[0019] In other words, as long as the CPU resources corresponding to a display screen are not turned off, the DPU and the host frame buffer will not be powered down and will not enter a sleep state. This allows the DPU to still read image data from the host frame buffer and send image data to the DDIC to drive the display screen to show the image.
[0020] In one possible implementation, the power mode of the electronic device is in hibernation mode, and the method further includes: the CPU, GPU, and DPU are all kept powered on.
[0021] When the power mode is in sleep mode, the CPU, GPU and DPU in the SOC remain powered on. The DPU can continuously send image data to the DDIC, and the DDIC can drive the display to show dynamic images, enabling the electronic device to support AOD and smart table setting functions.
[0022] In a second aspect, an electronic device is provided, including a processor and a memory, wherein instructions are stored in the memory, and when the processor executes the instructions, the electronic device performs the method as described in the first aspect and any embodiment thereof.
[0023] Thirdly, a computer-readable storage medium is provided, including instructions that, when executed on an electronic device, cause the electronic device to perform the method as described in the first aspect and any embodiment thereof.
[0024] Fourthly, a computer program product containing instructions is provided, which, when executed on the aforementioned electronic device, cause the electronic device to perform the method as described in the first aspect and any embodiment thereof.
[0025] The technical effects of the second to fourth aspects refer to the technical effects of the first aspect and any of its embodiments, and will not be repeated here. Attached Figure Description
[0026] Figure 1 is a schematic diagram of an always-on display (AOD) provided in an embodiment of this application;
[0027] Figure 2 is a schematic diagram of a partial AOD provided in an embodiment of this application;
[0028] Figure 3 is a schematic diagram of a smart table provided in an embodiment of this application;
[0029] Figure 4 is a schematic diagram of the appearance of an electronic device provided in an embodiment of this application;
[0030] Figure 5 is a schematic diagram of the structure of an electronic device provided in an embodiment of this application;
[0031] Figure 6 is a schematic diagram of a software system running on an electronic device according to an embodiment of this application;
[0032] Figure 7 is a schematic diagram of the structure of a SOC and a display screen provided in an embodiment of this application;
[0033] Figure 8 is a schematic diagram of another SOC and display structure provided in an embodiment of this application;
[0034] Figure 9 is a schematic diagram illustrating how the CPU, GPU, DPU, and host frame buffer in the SOC hibernate in a hibernation / suspend mode, according to an embodiment of this application.
[0035] Figure 10 is a schematic diagram of the state machine of a power mode of an electronic device provided in an embodiment of this application;
[0036] Figure 11 is a schematic diagram of a process for shutting down CPU resources according to an embodiment of this application;
[0037] Figure 12 is a flowchart illustrating a display method provided in an embodiment of this application;
[0038] Figure 13 is a flowchart illustrating another display method provided in an embodiment of this application. Detailed Implementation
[0039] First, some concepts involved in this application will be described.
[0040] The terms "first" and "second" used in the embodiments of this application are only used to distinguish features of the same type and should not be construed as indicating relative importance, quantity, order, etc.
[0041] The terms "exemplary" or "for example" used in the embodiments of this application are used to indicate examples, illustrations, or descriptions. Any embodiment or design described as "exemplary" or "for example" in this application should not be construed as being more preferred or advantageous than other embodiments or designs. Specifically, the use of terms such as "exemplary" or "for example" is intended to present the relevant concepts in a specific manner.
[0042] The terms "coupling" and "connection" used in the embodiments of this application should be interpreted broadly. For example, they can refer to a physical direct connection or an indirect connection achieved through electronic devices, such as a connection achieved through resistors, inductors, capacitors or other electronic devices.
[0043] Always-on Display (AOD) function: AOD allows electronic devices to display wallpaper, time, date, SMS messages, and call reminders when the screen is off. AOD satisfies users' need to access important information at any time while effectively reducing the power consumption of electronic devices. AOD modes include global AOD mode (also known as global always-on display mode) as shown in Figure 1 and partial AOD mode (also known as partial always-on display mode) as shown in Figure 2. When an electronic device enters partial AOD mode, a specific area of the display is lit while other areas remain dark. Partial AOD can reduce power consumption by lowering the DDIC power supply voltage. When an electronic device enters global AOD mode, the entire display is lit. Global AOD can reduce power consumption by lowering the refresh rate.
[0044] Smart Display Function: The smart display function allows electronic devices to display clock-like items when the screen is locked or off and the device is placed horizontally. As shown in Figure 3, after entering smart display mode, the electronic device simulates the display of a calendar, clock, etc.
[0045] Both the AOD (Ahead-of-Date) and Smart Display functions support refreshing both dynamic and static images. To reduce power consumption, the refresh rate for dynamic images is typically higher than that for static images; for example, a 30Hz refresh rate for dynamic images and a 1Hz refresh rate for static images. Similarly, when displaying a live wallpaper via AOD, a dynamic image refresh can be used, and vice versa. Furthermore, when displaying a minimum time unit of seconds via the Smart Display function, a dynamic image refresh can be used; when displaying a minimum time unit of minutes, a static image refresh can be used.
[0046] As shown in Figure 4, this application embodiment provides an electronic device 101, which can be referred to as user equipment (UE), access terminal, terminal unit, subscriber unit, terminal station, mobile station (MS), mobile station, terminal agent, or terminal device, etc. For example, this electronic device can be a mobile phone, tablet computer, laptop computer, smart bracelet, smart screen, smartwatch, earphone, smart speaker, terminal in industrial control, terminal in self-driving, terminal in remote medical care, terminal in smart grid, terminal in transportation safety, terminal in smart city, terminal in smart home, etc. This application embodiment does not limit the specific type and structure of the electronic device. One possible structure of the electronic device is described below.
[0047] As shown in Figure 5, taking a mobile phone as an example, electronic device 101 may include, at the hardware level, a processor 210, an external memory interface 220, an internal memory 221, a universal serial bus (USB) interface 230, a charging management module 240, a power management module 241, a battery 242, antenna 1, antenna 2, a mobile communication module 250, a wireless communication module 260, an audio module 270, a speaker 270A, a receiver 270B, a microphone 270C, a headphone jack 270D, a sensor module 280, buttons 290, an indicator 292, a camera 293, a display screen 294, and a subscriber identification module (SIM) card interface 295, etc. Optionally, in some embodiments, an audio digital signal processor (ADSP) may also be included.
[0048] It is understood that the structures illustrated in the embodiments of this application do not constitute a specific limitation on the electronic device 101. In other embodiments of this application, the electronic device 101 may include more or fewer components than illustrated, or combine some components, or split some components, or have different component arrangements. The illustrated components may be implemented in hardware, software, or a combination of software and hardware.
[0049] Processor 210 may include one or more processing units, such as: a field-programmable gate array (FPGA), an application-specific integrated circuit (ASIC), a system-on-chip (SoC), a central processing unit (CPU), an application processor (AP), a network processor (NP), a digital signal processor (DSP), a microcontroller unit (MCU), a programmable logic device (PLD), a modem processor, a graphics processing unit (GPU), an image signal processor (ISP), a controller, a video codec, a baseband processor, and a neural-network processing unit (NPU), etc. Different processing units may be independent devices or integrated into one or more processors. For example, processor 210 may be an application processor (AP). Alternatively, processor 210 may be integrated into a system-on-chip (SoC). Or, processor 210 may be integrated into an integrated circuit (IC) chip. The processor 210 may include an analog front end (AFE) and a micro-controller unit (MCU) in an IC chip.
[0050] The ADSP can be coupled to the audio module 270 and the sensor module 280. The ADSP can process audio signals and sensor data. Even when the processor is in sleep mode, the ADSP can continue operating, thereby reducing the power consumption of the electronic device.
[0051] It is understood that the interface connection relationships between the modules illustrated in the embodiments of this application are merely illustrative and do not constitute a structural limitation on the electronic device 101. In other embodiments of this application, the electronic device 101 may also adopt different interface connection methods or a combination of multiple interface connection methods as described in the above embodiments.
[0052] The external memory interface 220 can be used to connect an external memory card, thereby expanding the storage capacity of the electronic device 101. The external memory card communicates with the processor 210 through the external memory interface 220 to perform data storage functions. For example, music, video, and other files can be saved on the external memory card.
[0053] Internal memory 221 can be used to store computer executable program code, which includes computer instructions. Processor 210 executes various functional applications and data processing of electronic device 101 by running the computer instructions stored in internal memory 221, such as executing the display method involved in the embodiments of this application. In addition, internal memory 221 may include high-speed random access memory, and may also include non-volatile memory, such as at least one disk storage device, flash memory device, universal flash storage (UFS), etc.
[0054] The memory involved in the embodiments of this application can be volatile memory or non-volatile memory, or may include both volatile and non-volatile memory. The non-volatile memory can be read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), or flash memory. The volatile memory can be random access memory (RAM), which is used as an external cache. By way of example, but not limitation, many forms of RAM are available, such as static random access memory (SRAM), dynamic random access memory (DRAM), synchronous dynamic random access memory (SDRAM), double data rate synchronous dynamic random access memory (DDR SDRAM), enhanced synchronous dynamic random access memory (ESDRAM), synchronous linked dynamic random access memory (SLDRAM), and direct rambus RAM (DR RAM). It should be noted that the memory used in the systems and methods described herein is intended to include, but is not limited to, these and any other suitable types of memory.
[0055] Electronic device 101 can implement audio functions such as music playback and recording through audio module 270, speaker 270A, receiver 270B, microphone 270C, headphone jack 270D, and application processor.
[0056] Audio module 270 is used to convert digital audio information into analog audio signal output, and also to convert analog audio input into digital audio signal. In some embodiments, audio module 270 may be located in processor 210, or some functional modules of audio module 270 may be located in processor 210. Speaker 270A, also called a "loudspeaker," is used to convert audio electrical signals into sound signals. Receiver 270B, also called a "handpiece," is used to convert audio electrical signals into sound signals. Microphone 270C, also called a "microphone" or "microphone," is used to convert sound signals into electrical signals. Electronic device 101 may be equipped with at least one microphone 270C. Headphone jack 270D is used to connect wired headphones. Headphone jack 270D may be a USB interface 230, or a 3.5mm Open Mobile Terminal Platform (OMTP) standard interface, or a Cellular Telecommunications Industry Association of the USA (CTIA) standard interface.
[0057] Buttons 290 include a power button, volume buttons, etc. Buttons 290 can be mechanical buttons or touch buttons. Electronic device 101 can receive button input and generate key signal inputs related to user settings and function control of electronic device 101. Indicator 292 can be an indicator light, used to indicate charging status, battery level changes, and also to indicate messages, missed calls, notifications, etc. SIM card interface 295 is used to connect a SIM card. The SIM card can be inserted into or removed from the SIM card interface 295 to achieve contact and separation with electronic device 101. Electronic device 101 can support one or N SIM card interfaces, where N is a positive integer greater than 1. SIM card interface 295 can support Nano SIM cards, Micro SIM cards, SIM cards, etc. In some embodiments, electronic device 101 uses an embedded SIM (eSIM) card, which can be embedded in electronic device 101 and cannot be separated from it.
[0058] Electronic device 101 can implement display functions through a GPU, display screen 294, and application processor. The GPU is a microprocessor for image processing, connected to the display screen 294 and the application processor. The GPU is used to perform mathematical and geometric calculations and for graphics rendering. Processor 210 may include one or more GPUs, which execute computer instructions to generate or modify display information.
[0059] The sensor module 280 may include pressure sensors, gyroscopes or gravity sensors, barometric pressure sensors, magnetic field sensors, acceleration sensors, distance sensors, structured light sensors, proximity sensors, fingerprint sensors, temperature sensors, touch sensors, ambient light sensors, etc.
[0060] Battery 242 may include one or more batteries to power a load.
[0061] The charging management module 240 is used to receive charging input from a charger. The charger can be a wireless charger, such as a wireless charging dock or other terminal devices with reverse wireless charging functionality. The charging management module 240 can receive wireless charging input via the wireless charging coil of the terminal device. The charger can also be a wired charger; for example, the charging management module 240 can receive charging input from a wired charger via a USB interface 230. The charging management module 240 is also referred to as a charging chip.
[0062] The power management module 241 can charge the battery 242 while simultaneously supplying power to the terminal device. The power management module 241 receives input from the battery 242 and supplies power to the processor 210, internal memory 221, external memory interface 220, display screen 294, camera 293, and wireless communication module 260. The power management module 241 can also monitor parameters such as the battery 242's capacity, voltage, battery cycle count, and battery health status (leakage current, impedance). In some other embodiments, the power management module 241 may also be located within the processor 210.
[0063] The display screen 294 is used to display images, videos, etc. The display screen 294 includes a display panel. As shown in Figure 4A, the plane on which the display screen 294 of the electronic device 101 is located is referred to as the front side. In some embodiments, the electronic device 101 may include one or more display screens 294.
[0064] Camera 293 is used to capture still images or moving videos (collectively referred to as images). In some embodiments, electronic device 101 may include one or N cameras 293, where N is a positive integer greater than 1. Camera 293 generally includes an optical lens and a photosensitive element, which can be any photosensitive device such as a charge-coupled device (CCD) or complementary metal-oxide-semiconductor (CMOS). During image capture, reflected light from the object being photographed passes through the optical lens and is projected onto the photosensitive element. The photosensitive element converts the received light signal into an electrical signal, which is then processed by the ISP and sent to the processor 210, thus obtaining a frame of image. For example, camera 293 may include a front-facing camera 2931 as shown in Figure 4A and a rear-facing camera 2932 as shown in Figure 4B.
[0065] The processor 210 may also include a memory for storing computer instructions and data. In some embodiments, the memory in the processor 210 is a cache memory. This memory can store computer instructions or data that the processor 210 has just used or that are being used repeatedly. If the processor 210 needs to use the same computer instructions or data again, it can retrieve them directly from the memory. This avoids repeated accesses, reduces the waiting time of the processor 210, and thus improves system efficiency.
[0066] In some embodiments, the processor 210 may include one or more interfaces. Interfaces may include an inter-integrated circuit (I2C) interface, an inter-integrated circuit sound (I2S) interface, a pulse code modulation (PCM) interface, a universal asynchronous receiver / transmitter (UART) interface, a mobile industry processor interface (MIPI), a general-purpose input / output (GPIO) interface, a subscriber identity module (SIM) interface, and / or a USB interface, etc.
[0067] The wireless communication function of electronic device 101 can be realized through antenna 1, antenna 2, mobile communication module 250, wireless communication module 260, modem processor and baseband processor.
[0068] Antennas 1 and 2 are used to transmit and receive electromagnetic wave signals. Each antenna in electronic device 101 can be used to cover one or more communication frequency bands. Different antennas can also be multiplexed to improve antenna utilization. For example, antenna 1 can be multiplexed as a diversity antenna for a wireless local area network. In some other embodiments, the antennas can be used in conjunction with a tuning switch.
[0069] Mobile communication module 250 can provide wireless communication solutions including 2G / 3G / 4G / 5G for use on electronic device 101. Wireless communication module 260 can provide wireless communication solutions including wireless local area networks (WLAN) (such as wireless fidelity (Wi-Fi) networks), Bluetooth (BT), global navigation satellite system (GNSS), satellite communication (such as satellite data communication and satellite voice communication), frequency modulation (FM), near field communication (NFC), and infrared (IR) technologies for use on electronic device 101. For example, wireless communication module 260 may include a satellite communication chip to enable satellite communication. Furthermore, antenna 1 of electronic device 101 is coupled to mobile communication module 250, and antenna 2 is coupled to wireless communication module 260, enabling electronic device 101 to communicate with networks and other devices via wireless communication technology.
[0070] As shown in Figure 6, it is operated by electronic devices. Taking the operating system as an example, the software architecture running on the processor 210 includes the Application Layer, Framework Layer, Hardware Abstraction Layer (HAL), and Kernel Layer.
[0071] The application layer can include a series of application packages, such as desktop, camera, calling, game, short video applications, etc.
[0072] The Hardware Abstraction Layer (HAL) is used to abstract hardware. The HAL hides the hardware interface details of a specific platform, providing the operating system with a virtual hardware platform and exhibiting hardware independence. For example, the HAL includes a hardware composer (HWC).
[0073] The framework layer provides application programming interfaces (APIs) and programming frameworks for applications in the application layer. The framework layer includes predefined implementation methods. For example, it includes surface projectors (SurfaceFlinger, SF).
[0074] HWC and SF are Two key components in a graphics system that work together to efficiently synthesize data from the graphics data buffer and send it to the display screen.
[0075] The primary function of HWC is to reduce the load on OpenGL and the GPU by compositing data from the graphics data buffer through hardware acceleration. HWC can leverage hardware features to optimize the compositing process and improve display performance.
[0076] SF is The core service in the graphics system is responsible for receiving data from graphics data buffers from multiple sources, compositing them, and sending the composited graphics buffer data to the display. During the compositing process, SurfaceFlinger can choose to use GPU compositing or hardware compositing (HWC). HWC hardware compositing is generally more efficient because it can leverage the features of the display hardware to accelerate the compositing process. SurfaceFlinger will choose the most appropriate compositing method based on the current situation and the capabilities of the hardware.
[0077] The kernel layer is the layer between hardware and software. For example, the kernel layer includes a display driver, etc. The display driver is used to send display instructions and image data to the display screen, and also to execute the display methods of the embodiments of this application.
[0078] Taking the processor as a SOC as an example, in one possible implementation, the display screen can have a local frame buffer to cache at least one frame of image data from the SOC. The display screen displays a static image by self-refreshing the cached image data. At this time, the SOC can go to sleep to reduce power consumption.
[0079] As shown in Figure 7, the SOC 41 includes a CPU 411, a GPU 412, a display processing unit (DPU) 413, and a host frame buffer 414. The display screen 42 includes a display panel 421, a display driver integrated circuit (DDIC) 422, and a local frame buffer 423. The DPU 413 and the DDIC 422 communicate via a mobile industry processor interface (MIPI) for purposes such as transmitting display commands and image data.
[0080] CPU 411 is used to provide raw image data.
[0081] The GPU 412 is used to render graphics based on image data.
[0082] The DPU 413 provides hardware to accelerate image processing tasks such as image compositing, scaling, color format conversion, color space conversion, and color processing.
[0083] The host frame buffer 414 is used to buffer at least one frame of image data from the CPU 411.
[0084] The DDIC 422 is the core component of the display screen 42. By sending drive signals and image data to the display panel 421, it controls the brightness and color of each pixel on the display panel 421, thereby displaying images on the display panel 421. The DDIC 422 has two operating modes: video mode and command mode.
[0085] In video mode, the SOC 41 first buffers image data in the host frame buffer 414, and then periodically sends image data and synchronization signals to the display screen 42 to drive the display panel 421 for display. Synchronization signals are used to achieve frame and line synchronization between the SOC 41 and the DDIC 422. Synchronization signals include vertical synchronization (VSYNC) and horizontal synchronization (HSYNC). The VSYNC and HSYNC signals are pulse signals; the appearance of the VSYNC signal indicates the start of a new frame, and the appearance of the HSYNC signal indicates the end of one line and the start of the next. In this mode, the SOC 41 and MIPI cannot sleep, making it suitable for displaying dynamic images.
[0086] In command mode, the SOC 41 first buffers the image data in the host frame buffer 414, then sends the image data to the local frame buffer 423 of the display screen 42, and sends commands to the DDIC 422. These commands can specify parameters such as the refresh rate. The DDIC 422 reads the image data from the local frame buffer 423 and refreshes it line by line. While waiting to refresh the last line, the DDIC 422 sends a tearing effect signal (TE) to the SOC 41 to indicate that the image data for the current frame has been refreshed, and the SOC 41 can then send the next frame of image data. This achieves frame synchronization between the SOC 41 and the DDIC 422. Command mode is suitable for low-frequency self-refreshing scenarios or scenarios displaying static images, and can reduce power consumption.
[0087] In addition to video mode and command mode, DDIC also has a video hybrid mode (VHM).
[0088] The video hybrid mode refers to the ability of the SOC 41 to switch between a high-frequency refresh sub-mode and a low-frequency self-refresh sub-mode. For example, it can use the high-frequency refresh sub-mode when refreshing at a high frequency (e.g., 30Hz) and the low-frequency self-refresh sub-mode when self-refreshing at a low frequency (e.g., 1Hz). The high-frequency refresh sub-mode is similar to the video mode and will not be described further here. In the low-frequency self-refresh sub-mode, the SOC 41 first buffers the image data in the host frame buffer 414, then transmits it to the local frame buffer 423 of the display screen 42, and sends commands to the DDIC 422. These commands can indicate parameters such as the low-frequency (e.g., 1Hz) refresh rate. The DDIC 422 performs self-refreshing according to the refresh rate.
[0089] In another possible implementation, the display may not have a local frame buffer; such a display is called a RAM-free display.
[0090] As shown in Figure 8, the SOC 41 includes a CPU 411, a GPU 412, a display processing unit (DPU) 413, and a host frame buffer 414. The display screen 43 includes a display panel 431, a display driver integrated circuit (DDIC) 432, and a line buffer 433. The display screen 43 does not have a local frame buffer, but it does have a line buffer 433. The difference between the line buffer 433 and the local frame buffer is that the local frame buffer can buffer one frame of image data, while the line buffer 433 can buffer one line of image data, reducing the power consumption of reading and writing to the local frame buffer and the power consumption of maintaining image data.
[0091] The DDIC 432 in the RAMless display operates in RAMless video mode. In this mode, the DDIC 432 cannot self-refresh; instead, the DPU 413 in the SOC 41 first caches the image data in the host frame buffer 414, then sends the image data line by line to the line buffer 433 according to the refresh rate, and sends a synchronization signal to the DDIC 432. The DDIC 432 reads the image data from the line buffer 433 based on the synchronization signal and drives the display panel 431 to display the image. In this mode, the DPU 413, host frame buffer 414, and MIPI cannot hibernate, while the CPU 411 and GPU 412 can hibernate to reduce power consumption.
[0092] In related technologies, for those based on For electronic devices operating systems, in Doze Suspend mode, DDIC only supports command mode or VHM mode, and does not support the RAM-free video mode shown in Figure 8. Figure 9 is a flowchart illustrating how the CPU, GPU, DPU, and host frame buffer in the SOC hibernate in Doze Suspend mode, executed by the display driver shown in Figure 6, including S101-S107:
[0093] S101, The display driver iterates through each display screen.
[0094] Electronic devices may include multiple displays, such as a main screen and a secondary screen, an inner screen and an outer screen. These displays can be collectively referred to as displays, and each display is driven by a separate DDIC. Traversing each display means performing subsequent steps for each display to achieve independent control of each display.
[0095] S102, The display driver obtains the power mode of the electronic device and the operating mode of the display's DDIC.
[0096] The working modes of DDIC can be referred to the relevant descriptions in Figures 7 and 8, and will not be repeated here.
[0097] Figure 10 is a schematic diagram of the power mode state machine of an electronic device. The power mode state machine of an electronic device is maintained by a separate management thread, responsible for switching between different modes. The power mode of an electronic device is related to the device's usage state and power consumption. Specifically, the power modes of an electronic device include ON mode, OFF mode, Doze mode, and Doze Suspend mode.
[0098] Screen-on mode refers to the mode in which the display screen of an electronic device is in normal display condition. When an electronic device enters screen-on mode, all functions and applications can operate normally, and relevant functions can be performed according to user scenarios, such as playing videos, listening to music, making phone calls, taking photos, etc.
[0099] Screen-off mode, also known as always-on mode, is a mode in which the display screen of an electronic device is not showing any images. When an electronic device enters screen-off mode, almost all functions cannot be operated normally, most hardware is powered off, and functions such as displaying images and responding to touch cannot be used as they do in screen-on mode.
[0100] Hibernation mode is The feature mode introduced in version 6.0 primarily aims to reduce background application activity and extend standby time when electronic devices are idle for extended periods. When an electronic device enters sleep mode, the system limits network access and central processing unit (CPU) usage by background applications to reduce power consumption and improve battery life.
[0101] Hibernation / Suspend mode is The Hibernation / Suspend mode, introduced in Android 9.0, is a further improvement upon Hibernation / Suspend mode. When an electronic device enters Hibernation / Suspend mode, the system more strictly limits the activity of background applications, and may even suspend the execution of background applications, in order to further reduce the power consumption of the electronic device and improve its battery life.
[0102] The switching conditions between the various modes are shown in C1-C9 of Figure 10.
[0103] C1. When the electronic device is normally lit up and has AOD (global AOD or local AOD) or smart placement function enabled: If the electronic device receives a user pressing the power button, or if it does not receive a user touch operation within a preset time, it will switch from normal screen display to AOD mode or smart placement mode to refresh the dynamic image. At the same time, the power mode of the electronic device will switch from screen-on mode to sleep mode.
[0104] C2. When the electronic device is in AOD mode or smart display mode and refreshing dynamic images: If the electronic device receives a touch operation from the user, it will switch from refreshing dynamic images in AOD mode or smart display mode (e.g., refresh rate 30Hz) to normal screen display, and at the same time, the power mode of the electronic device will switch from sleep mode to screen-on mode.
[0105] C3. When the electronic device is in AOD mode or smart display mode and refreshing dynamic images: If the electronic device switches from refreshing dynamic images (e.g., refresh rate 30Hz) in AOD mode or smart display mode to refreshing static images (e.g., refresh rate 1Hz), the power mode of the electronic device will switch from sleep mode to sleep suspend mode at the same time.
[0106] C4. When the electronic device is in AOD mode or smart display mode and refreshing a static image: If the electronic device switches from refreshing a static image (e.g., refresh rate 1Hz) in AOD mode or smart display mode to refreshing a dynamic image (e.g., refresh rate 30Hz), the power mode of the electronic device will switch from sleep suspend mode to sleep mode at the same time.
[0107] C5. When the electronic device is in AOD mode or smart display mode and refreshing a static image: If the electronic device does not receive a user touch operation within a preset time, it will switch from refreshing a static image in AOD mode or smart display mode to screen off, and at the same time, the power mode of the electronic device will switch from sleep suspend mode to screen off mode.
[0108] C6. When the electronic device is off and the AOD (Always On Demand) or Smart Tabletop function is enabled: If the electronic device receives a touch operation from the user, it will switch from screen off mode to AOD mode or Smart Tabletop mode, and at the same time, the power mode of the electronic device will switch from screen off mode to sleep mode.
[0109] C7. When the electronic device is in AOD mode or smart display mode and refreshing dynamic images: If the electronic device does not receive a user touch operation within a preset time, it will switch from refreshing dynamic images in AOD mode or smart display mode to screen off, and at the same time, the power mode of the electronic device will switch from sleep mode to screen off mode.
[0110] C8. When the electronic device is normally on and the AOD function or smart table setting function is not enabled: If the electronic device receives a user pressing the power button, or if it does not receive a user touch operation within a preset time, it will switch from normal on display to off display, and the power mode of the electronic device will switch from on display mode to off display mode.
[0111] C9. When the electronic device screen is off and the AOD function or smart placement function is not turned on: If the electronic device receives the user's operation of pressing the power button, or receives the user's touch operation, it will switch from screen off to normal screen on display, and at the same time the power mode of the electronic device will switch from screen off mode to screen on mode.
[0112] Since the SOC needs to continuously send image data and synchronization signals to the display screen when the DDIC is in video mode or VHM mode high-frequency refresh sub-mode, the electronic device cannot enter sleep mode or sleep suspension mode at this time. Therefore, it is not necessary to consider the electronic device entering sleep state or sleep suspension state when the DDIC is in video mode or VHM mode high-frequency refresh sub-mode. It is only necessary to consider the electronic device entering sleep state or sleep suspension state when the DDIC is in command mode or VHM mode low-frequency self-refresh sub-mode.
[0113] If the power mode is sleep mode and the DDIC's operating mode is command mode, or if the power mode is sleep mode and the DDIC's operating mode is the low-frequency self-refresh sub-mode of VHM mode, then jump to S103 to request a switch from sleep mode to sleep suspend mode to further reduce the power consumption of the electronic device. Otherwise, further determine whether the power mode is sleep suspend mode or whether the DDIC's operating mode is the low-frequency self-refresh sub-mode of VHM mode. If the power mode is sleep suspend mode or the DDIC's operating mode is the low-frequency self-refresh sub-mode of VHM mode, then jump to S104; otherwise, jump to S102.
[0114] S103, The display driver requests that the power mode of the electronic device be switched from hibernation mode to hibernation suspend mode.
[0115] The display driver can request the power mode management thread of the power mode state machine to switch the electronic device's power mode from sleep mode to sleep-suspend mode. Whether the switch to sleep-suspend mode is actually successful depends on the state machine management thread. Compared to sleep mode, electronic devices consume less power when in sleep-suspend mode.
[0116] If the power mode is hibernation / suspend mode, or the DDIC operating mode is low-frequency self-refresh sub-mode of VHM mode, then jump to S104; otherwise, jump to S102.
[0117] S104, Display driver deactivation flag.
[0118] The flags indicate whether the CPU resources corresponding to the display are active. Setting the inactive flag indicates that the CPU resources corresponding to the display need to be disabled. Each display corresponds to independent CPU resources, which include the CPU's display thread and interrupt event thread. The CPU's display thread is used by the CPU to transmit image data to the DDIC via the DPU. The interrupt event thread is used by the CPU to process interrupt events fed back by the DPU. For example, interrupt events include interrupts instructing the DPU to complete transmitting image data, and TE signals sent from the DDIC to the DPU.
[0119] S105, The display driver disables the CPU resources corresponding to the display screen.
[0120] After disabling the CPU resources corresponding to the display screen, if not all displays have been traversed, jump to S101 to traverse the next display screen; otherwise, jump to S106.
[0121] As shown in Figure 11, the CPU resources corresponding to turning off the display screen include S1051-S1052:
[0122] S1051, The display driver disables the CPU's display thread.
[0123] After the display driver shuts down the CPU's display thread, the CPU will no longer transmit image data to the DDIC via the DPU, and the CPU can then prepare to enter sleep mode.
[0124] If there is an interrupt event from the DPU that needs to be handled, the display driver waits for the interrupt event to be processed before shutting down the CPU's display thread. If there is no interrupt event that needs to be handled, the process jumps to S1052.
[0125] S1052, Display driver disables CPU interrupt event thread.
[0126] After the display driver disables the CPU's interrupt event thread, the CPU will no longer respond to interrupt events from the DPU, and the CPU can then prepare to enter sleep mode.
[0127] S106. If the CPU resources corresponding to all displays are turned off, the DPU and host frame buffer are powered down to enter hibernation mode.
[0128] In other words, as long as the CPU resources corresponding to one display screen are not turned off, the DPU and the host frame buffer will not be powered down and will not enter a sleep state. This allows the DPU to still read image data from the host frame buffer and send image data to the DDIC to drive the display screen to show the image.
[0129] S107. If the power mode of the electronic device is hibernation / suspend mode, the CPU and GPU are powered down to enter hibernation mode.
[0130] The above process ensures that in sleep mode and sleep suspend mode, regardless of whether the DDIC operates in command mode or the low-frequency self-refresh sub-mode of VHM mode, the DPU, host frame buffer, and MIPI in the SOC remain powered down to enter sleep mode, but the display can still show static images through self-refresh. However, when the DDIC operates in no-RAM video mode, because the DPU, host frame buffer, and MIPI are powered down to enter sleep mode, the DPU cannot continuously send image data to the display, and the display will not be able to display images.
[0131] Therefore, this application provides a display method that can be applied to the global AOD mode shown in Figure 1, the local AOD mode shown in Figure 2, and the smart table setting mode shown in Figure 3, etc. As shown in Figure 12, the display method includes:
[0132] S201. When the power mode of the electronic device is the first power mode (e.g., screen-on mode), the CPU, GPU, and DPU are all powered on so that the display screen can display images.
[0133] In the first power mode, the CPU, GPU, DPU, and host frame buffer in the SOC remain powered on and will not enter sleep mode. The display can remain on to show images and supports high-frequency (e.g., greater than or equal to 30Hz) image refresh rates.
[0134] S202, if a first user operation is received, or if no user touch operation is received within a preset time, the power mode of the electronic device is switched from the first power mode to the second power mode (e.g., sleep mode).
[0135] For example, the first user operation can be the user pressing the power button. When the electronic device has the AOD (Global AOD or Local AOD) function or the smart table setting function turned on, if the electronic device receives the user pressing the power button, or if it does not receive the user's touch operation within a preset time, the power mode of the electronic device switches from the first power mode to the second power mode.
[0136] S203. When the power mode of the electronic device is the second power mode, the CPU, GPU, and DPU are all kept powered on so that the display screen can display images.
[0137] When an electronic device switches its power mode from the first power mode to the second power mode, the electronic device can enter a local AOD mode, a global AOD mode, or a smart placement mode.
[0138] In sleep mode, the CPU, GPU, DPU, and host frame buffer in the SOC remain powered on and do not enter sleep mode. When the electronic device enters global AOD mode or smart placement mode, the display can remain on and support adaptive (e.g., 1Hz-60Hz) refresh rates for dynamic images. The DPU can further reduce the display brightness by sending backlight commands to the DDIC, and can also further reduce the display's grayscale through local tone mapping (LTM), thereby reducing power consumption. When the electronic device enters partial AOD mode, the display can remain on in a low-power mode and support adaptive (e.g., 1Hz-30Hz) refresh rates for dynamic images. In other words, even in sleep mode, AOD and smart placement functions are supported.
[0139] S204. In response to not receiving a user touch operation within a preset time, the power mode of the electronic device is switched from the second power mode to the third power mode (e.g., sleep / suspend mode).
[0140] S205. When the power mode of the electronic device is the third power mode (e.g., hibernation / suspend mode), the CPU and GPU remain powered down, while the DPU remains powered on so that the display screen can display images.
[0141] When an electronic device switches from the second power mode to the third power mode, the electronic device can remain in local AOD mode, global AOD mode, or smart placement mode.
[0142] In sleep / suspend mode, if the display does not have a local frame buffer, the DDIC operates in a RAM-free video mode. The DPU and host frame buffer in the SOC remain powered on, while the CPU and GPU remain powered off to enter sleep mode, thus reducing power consumption. In global AOD mode or smart placement mode, the display can remain continuously lit and supports low-frequency (e.g., 1Hz) refresh rates for static images. The brightness or grayscale of the display can be further reduced to lower power consumption. In partial AOD mode, the display can remain continuously lit in a low-power mode and supports low-frequency (e.g., 1Hz) refresh rates for static images.
[0143] When the power mode is in sleep / suspend mode, if the display has a local frame buffer, the DDIC operates in command mode or a low-frequency self-refresh sub-mode of VHM mode. The CPU, GPU, DPU, and host frame buffer in the SOC remain powered down. In global AOD mode or smart placement mode, the display can remain on and support DDIC self-refresh, while reducing brightness or grayscale to lower power consumption. In partial AOD mode, the display can remain on in a low-power mode and support DDIC self-refresh.
[0144] S206. In response to not receiving a user touch operation within a preset time, the power mode of the electronic device is switched from the third power mode to the fourth power mode (e.g., screen off mode).
[0145] When the power mode is screen-off mode, the CPU, GPU, DPU, and host frame cache in the SOC are all powered down, the display screen is off, no images are displayed, and image refresh is not supported, in order to reduce power consumption.
[0146] The display screen in this application embodiment can be an adaptive refresh panel (ARP) that supports a RAM-free video mode, such as a low-temperature polycrystalline oxide (LTPO) display screen. Currently, LTPO display screens can have refresh rates as low as 1Hz. By reducing the refresh rate of the display screen, the power consumption of electronic devices can be reduced. The display screen in this application embodiment can also be a display screen that supports command mode, video mode, and VHM mode, such as a low-temperature polysilicon (LTPS) display screen.
[0147] Because the CPU, GPU, DPU, and host frame buffer in the SOC remain powered on in both screen-on and sleep modes, and powered off in screen-off mode, the DPU and host frame buffer only become powered on or off in sleep / suspend mode. Therefore, as shown in Figure 13, for sleep / suspend mode, this application embodiment provides another display method, which can be executed by the display driver shown in Figure 6. This display method includes:
[0148] S301, the display driver iterates through each display screen.
[0149] This step is the same as S101 and will not be repeated here.
[0150] S302, The display driver obtains the power mode of the electronic device.
[0151] This step is the same as S102, and will not be repeated here.
[0152] If the electronic device's power mode is sleep mode, proceed to S303. If the electronic device's power mode is not sleep mode or sleep suspend mode, for example, if the electronic device's power mode is screen-on mode, proceed to S302, i.e., wait for the electronic device's power mode to switch to sleep mode or sleep suspend mode. If the electronic device's power mode is sleep suspend mode, proceed to S304.
[0153] In other words, the need to power down the DPU is only considered when the electronic device's power mode is in sleep / suspend mode, where the DPU might experience power-up or power-down cycles. In sleep mode and screen-on mode, the CPU, GPU, and DPU remain powered on. The DPU can continuously send image data to the DDIC, which in turn drives the display to show dynamic images, enabling the electronic device to support AOD (Always-On) and smart screen placement functions. In screen-off mode, the CPU, GPU, and DPU are all powered down, and the display does not show images to reduce the electronic device's power consumption.
[0154] It should be noted that when the power mode of the electronic device is screen-off mode, the CPU has already been powered down and entered hibernation, and will not execute the display method involved in the embodiments of this application. Therefore, it is not necessary to consider the case where the power mode of the electronic device is screen-off mode.
[0155] S303, The display driver requests that the power mode of the electronic device be switched from hibernation mode to hibernation suspend mode.
[0156] This step is the same as S103 and will not be repeated here.
[0157] It should be noted that in S302 and S303, if the power mode of the electronic device is either screen-on or screen-off, it will wait for the power mode of the electronic device to switch to sleep mode or sleep-suspended mode. If the power mode of the electronic device is sleep mode, it will request to switch the power mode to sleep-suspended mode. Therefore, when executing subsequent steps, the power mode of the electronic device must already be in sleep-suspended mode. Compared to the scheme shown in Figure 9, which requires simultaneous determination of the power mode of the electronic device and the operating mode of the DDIC, the scheme shown in Figure 13 decouples the power mode of the electronic device from the operating mode of the DDIC.
[0158] S304, Display driver obtains DDIC working mode.
[0159] The working modes of DDIC can be referred to the relevant descriptions in Figures 7 and 8, and will not be repeated here.
[0160] If the DDIC operates in no-RAM video mode, jump to S305. Otherwise, if the DDIC does not operate in no-RAM video mode, jump to S306.
[0161] S305: The display driver keeps the DPU and host frame buffer powered on, thus preventing them from entering a sleep state.
[0162] This means skipping the step of shutting down the CPU resources corresponding to that display, and no longer traversing other displays, while keeping the DPU and host frame buffer powered on. This allows the DPU to still read image data from the host frame buffer and send image data and synchronization signals to the display's DDIC according to the refresh rate, thereby driving the display to show the image.
[0163] S306, Display driver deactivation flag.
[0164] This step is described in S104 and will not be repeated here.
[0165] S307. The display driver disables the CPU resources corresponding to this display screen.
[0166] This step is described in S105 and will not be repeated here.
[0167] After disabling the CPU resources corresponding to the display, if not all displays have been traversed, jump to S301; otherwise, jump to S308.
[0168] S308. If the CPU resources corresponding to all displays are turned off, the DPU and host frame buffer are powered down to enter hibernation mode.
[0169] This step is described in S106 and will not be repeated here.
[0170] S309, CPU, and GPU are powered down to enter hibernation mode.
[0171] Powering down the CPU and GPU to enter a sleep state can reduce the power consumption of electronic devices.
[0172] The display method provided in this application can be applied to displays that do not have a local frame buffer and whose DDIC operating mode is a RAM-free video mode. In sleep / suspend mode, although the CPU and GPU are powered down to enter sleep mode, the DPU remains powered on and can still read image data from the host frame buffer and drive the display to show the image. This enables electronic devices to still display images in sleep / suspend mode.
[0173] This application also provides a computer-readable storage medium including instructions that, when executed on the electronic device, cause the electronic device to perform the steps in the above method embodiments, such as performing the methods shown in FIG9, FIG11, FIG12, and FIG13.
[0174] This application also provides a computer program product including instructions that, when executed on the above-mentioned electronic device, cause the electronic device to perform the various steps in the above-mentioned method embodiments, such as executing the methods shown in FIG9, FIG11, FIG12, and FIG13.
[0175] The technical effects of computer-readable storage media and computer program products are described in the preceding method embodiments.
[0176] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.
Claims
1. A display method, characterized in that, The method is applied to an electronic device, which includes a system-on-a-chip (SoC) and a display screen. The SoC includes a central processing unit (CPU), a graphics processing unit (GPU), a display processing unit (DPU), and a host frame buffer. The display screen includes a display driver integrated circuit (DDIC). When the power mode of the electronic device is the first power mode, the CPU, the GPU, and the DPU are all kept powered on so that the display screen can display images, wherein the first power mode is the screen-on mode; Upon receiving a first user operation, or if no user touch operation is received within a preset time, the power mode of the electronic device switches from the first power mode to a second power mode, wherein the second power mode is a sleep mode. When the power mode of the electronic device is the second power mode, the CPU, the GPU, and the DPU are all powered on so that the display screen can display images; In response to the absence of a user touch operation within a preset time, the power mode of the electronic device switches from a second power mode to a third power mode, wherein the third power mode is a sleep / suspend mode. When the power mode of the electronic device is the third power mode, the CPU and the GPU are both powered down, while the DPU is powered on so that the display screen can display images.
2. The method according to claim 1, characterized in that, When the power mode of the electronic device is switched from the first power mode to the second power mode, the electronic device enters a local always-on display (AOD) mode, a global AOD mode, or a smart table setting mode.
3. The method according to claim 2, characterized in that, When the power mode of the electronic device switches from the second power mode to the third power mode, the electronic device remains in the local AOD mode, the global AOD mode, or the smart table setting mode.
4. The method according to claim 2 or 3, characterized in that, The method further includes: When the electronic device is in the global AOD state, reduce the brightness or grayscale of the display screen.
5. The method according to any one of claims 1-4, characterized in that, When the CPU and GPU are both powered down, and the DPU is powered on to display an image on the screen, the DDIC operates in RAM-free video mode.
6. The method according to any one of claims 1-4, characterized in that, The method further includes: When the power mode of the electronic device is the third power mode, if the working mode of the DDIC is not the no-RAM video mode, the CPU resources corresponding to the display screen are turned off; the CPU resources corresponding to the display screen include the display thread and the interrupt event thread of the CPU. The display thread is used by the CPU to transmit image data to the DDIC through the DPU, and the interrupt event thread is used by the CPU to process the interrupt events fed back by the DPU.
7. The method according to claim 6, characterized in that, The display screens are multiple, and the method further includes: The DPU is powered down if all CPU resources corresponding to the displays are turned off.
8. An electronic device, characterized in that, The electronic device includes a processor and a memory, wherein the memory stores instructions, and when the processor executes the instructions, the electronic device performs the method as described in any one of claims 1-7.
9. A computer-readable storage medium, characterized in that, Includes instructions that, when executed on an electronic device, cause the electronic device to perform the method as described in any one of claims 1-7.
10. A computer program product containing instructions, characterized in that, When the instructions are executed on an electronic device, the electronic device causes the electronic device to perform the method as described in any one of claims 1-7.