Control circuit for screen display, screen driving circuit, chip and screen

Abstract

According to the control circuit for screen display, the screen driving circuit, the chip and the screen, the frame display enable signal can be changed by changing the total frame number in the unit time and the display frame number in the unit time, so that the time of displaying a pattern by the liquid crystal screen in the unit time is changed to realize gray scale adjustment, and the visual persistence principle is utilized to adjust the brightness of the liquid crystal display screen. The display effects of gradually brightening, gradually extinguishing, breathing and the like can be achieved, gray control is not limited by the electrical specification of a liquid crystal screen any more, the software control complexity is greatly reduced, and the good visual impression is achieved.

Description

Technical Field

[0001] The present application relates to the field of liquid crystal screen backlight driving technology, and in particular to a control circuit, a screen driving circuit, a chip and a screen for screen display. Background Art

[0002] Liquid crystal display (LCD screen) is widely used in display instruments due to its excellent characteristics such as low operating voltage, long working life, low power loss, easy integration, low electromagnetic radiation, and large amount of displayed information. However, due to the unique imaging principle of LCD screen, its display effect is relatively simple and cannot meet the application needs of the market. The existing scheme for adjusting LCD grayscale is achieved by adjusting the driving voltage, but the grayscale gear is limited by the electrical characteristics of the screen and it is impossible to select local pixels for grayscale control. In addition, the existing software solution can only be applied to the screen of 1 / 2BIAS, and the control program is relatively complex and has poor versatility. Summary of the invention

[0003] The present application provides a control circuit, a screen driving circuit, a chip and a screen for screen display. The specific technical solutions are as follows:

[0004] A control circuit for screen display, the control circuit for screen display comprising a first counter, a second counter, a comparator, a first data selector, a second data selector, a first AND gate, a second AND gate and a SEG terminal level selection signal generator, wherein the first input end of the comparator is connected to the first counter for receiving a total frame count value output by the first counter within a unit time, the second input end of the comparator is connected to the second counter for receiving a display frame count value output by the second counter within a unit time, the comparator is used to compare the total frame count value within the unit time with the display frame count value within the unit time, and then transmit the comparison result to the address selection end of the first data selector through the output end of the comparator; the first data selector selects the corresponding preset signal as a frame display enable signal according to the comparison result output by the comparator and transmits it to the first AND gate, the frame display enable signal is used to indicate Indicates whether the current frame needs to display an image; the first AND gate receives the frame display enable signal output by the first data selector and the externally transmitted liquid crystal screen display data and performs an AND operation, and then transmits the AND operation result to the first input end of the second data selector; the second AND gate receives the COM end breathing enable and the SEG end breathing enable and performs an AND operation, and then transmits the AND operation result to the address selection end of the second data selector; the second input end of the second data selector is used to receive the externally transmitted liquid crystal screen display data, and the second data selector selects the liquid crystal screen display data or the AND operation result of the first AND gate as the input of the SEG end level selection signal generator according to the AND operation result output by the second AND gate; the SEG end level selection signal generator is used to generate a corresponding SEG end level selection signal according to the liquid crystal screen display data or the AND operation result of the first AND gate, and the SEG end level selection signal is used to control the grayscale of the liquid crystal screen.

[0005] Furthermore, the control circuit for screen display also includes a first register and a second register, wherein the first register is connected to the first input terminal of the second AND gate for transmitting the breathing enable of the COM terminal to the second AND gate, and the second register is connected to the second input terminal of the second AND gate for transmitting the breathing enable of the SEG terminal to the second AND gate.

[0006] A screen driving circuit, the screen driving circuit includes the control circuit for screen display, the screen driving circuit also includes a data reading module, a register configuration module and a drive control signal generating module, wherein the data reading module and the register configuration module are respectively connected to the drive control signal generating module, the data reading module is used to read the liquid crystal screen display data stored in the external display memory and transmit it to the drive control signal generating module, the register configuration module is used to configure the functional parameters of the drive control signal generating module, the drive control signal generating module is used to generate a COM terminal level selection signal and a SEG terminal level selection signal according to the liquid crystal screen display data, wherein the drive control signal generating module includes the control circuit for screen display, and the SEG terminal level selection signal is used to control the grayscale of the liquid crystal screen.

[0007] Furthermore, the data reading module is connected to the first AND gate and the second data selector, and is used to read the LCD screen display data stored in the external video memory and transmit it to the first AND gate and the second data selector, wherein the control circuit for screen display includes the first AND gate and the second data selector.

[0008] Furthermore, the register configuration module is connected to the first counter, the second counter, the first register and the second register, and is used to configure the functional parameters of the control circuit for screen display, wherein the control circuit for screen display includes the first counter, the second counter, the first register and the second register.

[0009] Furthermore, the screen driving circuit includes a video memory control module, which is connected to the data reading module. The video memory control module communicates with the outside through an address bus and a data bus, and is used to control the external central processing unit to read and write the external video memory, so that the data reading module can read the LCD screen display data stored in the external video memory.

[0010] Furthermore, the screen driving circuit comprises a signal synchronization module, which is connected to the register configuration module and the driving control signal generating module and is used for synchronizing the system clock and the working clock of the screen driving circuit across time domains.

[0011] Furthermore, the screen driving circuit includes an analog voltage generating module, which is connected to the driving control signal generating module and is used to output an analog voltage for driving the liquid crystal screen according to the COM terminal level selection signal and the SEG terminal level selection signal.

[0012] A chip comprises the screen driving circuit.

[0013] A screen comprises the chip.

[0014] The control circuit for screen display described in the present application can change the frame display enable signal by changing the total number of frames per unit time and the number of displayed frames per unit time, thereby changing the time for the LCD screen to display a pattern per unit time to achieve grayscale adjustment. By utilizing the principle of visual persistence, display effects such as gradual brightening, gradual fading, and breathing can be achieved, so that grayscale control is no longer limited by the electrical specifications of the LCD screen, greatly reducing the complexity of software control and having a good visual perception. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 A schematic diagram of a control circuit for screen display according to an embodiment of the present application.

[0016] Figure 2 A schematic diagram of a screen driving circuit according to an embodiment of the present application.

[0017] Figure 3 This is a schematic diagram of the basic principle of grayscale control of a liquid crystal screen described in an embodiment of the present application.

[0018] Figure 4 A schematic diagram of a breathing enable start timing diagram according to an embodiment of the present application.

[0019] Figure 5 A schematic diagram of a breathing enable closing timing diagram according to an embodiment of the present application. DETAILED DESCRIPTION

[0020] The following will describe the technical solutions in the embodiments of the present application in detail in conjunction with the accompanying drawings in the embodiments of the present application. It should be understood that the specific embodiments described below are only used to explain the present application and are not used to limit the present application.

[0021] In the following description, specific details are given to provide a thorough understanding of the embodiments. However, one of ordinary skill in the art will appreciate that the embodiments may be practiced without these specific details. For example, circuits may be shown in block diagrams so as not to obscure the embodiments in unnecessary detail. In other cases, well-known circuits, structures, and techniques may not be shown in detail in order not to obscure the embodiments.

[0022] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0023] Liquid crystal display (LCD screen) is widely used in display instruments due to its excellent characteristics such as low operating voltage, long working life, low power loss, easy integration, low electromagnetic radiation, and large amount of displayed information. However, due to the unique imaging principle of LCD screen, its display effect is relatively simple and cannot meet the application needs of the market. The existing scheme for adjusting LCD grayscale is achieved by adjusting the driving voltage, but the grayscale gear is limited by the electrical characteristics of the screen and it is impossible to select local pixels for grayscale control. In addition, the existing software solution can only be applied to the screen of 1 / 2BIAS, and the control program is relatively complex and has poor versatility.

[0024] In order to solve the above technical problems, an embodiment of the present application provides a control circuit for screen display, which can change the frame display enable signal by changing the total number of frames per unit time and the number of displayed frames per unit time, thereby changing the time for the LCD screen to display a pattern per unit time to achieve grayscale adjustment. By utilizing the principle of visual persistence, display effects such as gradual brightening, gradual fading, and breathing can be achieved, so that grayscale control is no longer limited by the electrical specifications of the LCD screen, greatly reducing the complexity of software control and having a good visual perception.

[0025] like Figure 1As shown, the control circuit for screen display includes a first counter, a second counter, a comparator, a first data selector, a second data selector, a first AND gate, a second AND gate and a SEG terminal level selection signal generator, wherein the first input end of the comparator is connected to the first counter for receiving the total frame count value output by the first counter within a unit time, the second input end of the comparator is connected to the second counter for receiving the display frame count value output by the second counter within a unit time, the comparator is used to compare the total frame count value within the unit time with the display frame count value within the unit time, and then transmit the comparison result to the address selection end of the first data selector through the output end of the comparator; the first data selector selects the corresponding preset signal as a frame display enable signal according to the comparison result output by the comparator and transmits it to the first AND gate, and the frame display enable signal is used to indicate whether the current frame is whether it is necessary to display an image; the first AND gate receives the frame display enable signal output by the first data selector and the externally transmitted LCD screen display data and performs an AND operation, and then transmits the AND operation result to the first input end of the second data selector; the second AND gate receives the COM end breathing enable and the SEG end breathing enable and performs an AND operation, and then transmits the AND operation result to the address selection end of the second data selector; the second input end of the second data selector is used to receive the externally transmitted LCD screen display data, and the second data selector selects the LCD screen display data or the AND operation result of the first AND gate as the input of the SEG end level selection signal generator according to the AND operation result output by the second AND gate; the SEG end level selection signal generator is used to generate a corresponding SEG end level selection signal according to the LCD screen display data or the AND operation result of the first AND gate, and the SEG end level selection signal is used to control the grayscale of the LCD screen.

[0026] It should be noted that the liquid crystal display screen is controlled by two different groups of pins, one is the common electrode (i.e., COM terminal), which is used to control the horizontal pixels, and the other is the segment electrode (i.e., SEG terminal), which is used to control the vertical pixels. The commonly used control method at present is line-by-line scanning, that is, periodically turning on the COM terminal, first controlling the first row of pixels, then controlling the second row of pixels, and so on and so forth, and adding the control signal of the SEG terminal, all the pixels can be controlled. Therefore, the main function of the control circuit for screen display is to output the SEG terminal level selection signal to control the grayscale of the liquid crystal screen.

[0027] Reference Figure 1, the SEG terminal level selection signal is a waveform signal generated according to the LCD screen display data. Obviously, when the address selection terminal of the second data selector receives a low level 0, the second data selector selects the LCD screen display data to the SEG terminal level selection signal generator, so that the LCD screen will display the original data without a breathing effect (Note: the main application of grayscale control is the display of breathing effects). On the contrary, when the address selection terminal of the second data selector receives a high level 1, the second data selector selects the result of the AND operation of the LCD screen display data and the frame display enable signal, and the frame display enable signal has two states, high and low, which are used to indicate whether the current frame needs to display an image. In the change of high and low levels, the image displayed on the LCD screen produces a breathing effect, that is, grayscale control is achieved.

[0028] As one implementation mode, the control circuit for screen display further includes a first register and a second register, wherein the first register is connected to the first input terminal of the second AND gate, and is used to transmit the COM terminal breathing enable to the second AND gate, and the second register is connected to the second input terminal of the second AND gate, and is used to transmit the SEG terminal breathing enable to the second AND gate. The COM terminal breathing enable and the SEG terminal breathing enable are used to indicate whether the intersection of a certain COM terminal and a certain SEG terminal needs to breathe.

[0029] like Figure 2 As shown, an embodiment of the present application provides a screen driving circuit, the screen driving circuit includes the control circuit for screen display, the screen driving circuit also includes a data reading module LCD SRAM RD, a register configuration module LCD regs and a drive control signal generation module LCD timing gen, wherein the data reading module and the register configuration module are respectively connected to the drive control signal generation module, the data reading module is used to read the liquid crystal screen display data stored in the external display memory and transmit it to the drive control signal generation module, the register configuration module is used to configure the functional parameters of the drive control signal generation module, the drive control signal generation module is used to generate a COM terminal level selection signal and a SEG terminal level selection signal according to the liquid crystal screen display data, wherein the drive control signal generation module includes the control circuit for screen display, and the SEG terminal level selection signal is used to control the grayscale of the liquid crystal screen.

[0030] As one of the implementation modes, the data reading module is connected to a first AND gate and a second data selector, and is used to read the LCD screen display data stored in an external video memory and transmit it to the first AND gate and the second data selector, wherein the control circuit for screen display includes the first AND gate and the second data selector.

[0031] As one implementation mode, the register configuration module is connected to the first counter, the second counter, the first register and the second register, and is used to configure the functional parameters of the control circuit for screen display, wherein the control circuit for screen display includes the first counter, the second counter, the first register and the second register.

[0032] As one of the implementation modes, the screen driving circuit includes a video memory control module SRAM CTRL, which is connected to the data reading module. The video memory control module communicates with the outside through an address bus address bus and a data bus data bus, and is used to control an external central processing unit to read and write external video memory, so that the data reading module can read the LCD screen display data stored in the external video memory.

[0033] As one implementation manner, the screen driving circuit includes a signal synchronization module LCD Sync, which is connected to the register configuration module and the drive control signal generation module and is used to synchronize the system clock and the working clock of the screen driving circuit across time domains.

[0034] As one implementation mode, the screen driving circuit includes an analog voltage generating module analog part, which is connected to the driving control signal generating module and is used to output an analog voltage for driving the liquid crystal screen according to the COM terminal level selection signal and the SEG terminal level selection signal.

[0035] like Figure 3 As shown, the screen driving circuit described in the embodiment of the present application has the following configurable parameters: total number of frames per unit time total_frames, number of displayed frames per unit time disp_frames (i.e., number of frames of the image actually displayed per unit time), frame number change step length disp_step (i.e., the step length of the number of frames of the image actually displayed per adjacent unit time) and the operating frequency clk_lcd of the screen driving circuit. The unit time is called a grayscale update cycle, and the grayscale contrast of each grayscale update cycle can be approximately expressed as

[0036]

[0037] Among them, total_frames≥disp_frames, disp_frames≥disp_step.

[0038] As can be seen from the above, the LCD screen controls the pixels by scanning. In order to avoid flickering, the refresh rate of the screen should be greater than the minimum resolution of the human eye (about 30Hz, which is a priori value). When displaying normally, the relationship between the operating frequency of the screen drive circuit and the number of COM ports can be expressed as

[0039]

[0040] Where clk_lcd represents the operating frequency of the screen drive circuit. In the grayscale control mode, the operating frequency of the screen drive circuit depends on

[0041]

[0042] The screen driving circuit described in the embodiment of the present application also has the following configurable parameters: breathing control enable lcd_breath_en, used to indicate whether the liquid crystal screen is to produce a breathing effect; breathing effect selection signal lcd_breath_effect[1:0], used to indicate which breathing effect is displayed, and three effects can be selected: gradual brightening, gradual extinguishing, and breathing (i.e., alternating between bright and dark); breathing mode selection signal lcd_breath_mode, used to indicate which breathing mode is selected, set to 0 for continuous breathing display (for example, continuous alternation between bright and dark, and the breathing control enable can only be turned off by software), and set to 1 for single breathing display (for example, when the gradual extinguishing effect is selected, the hardware automatically turns off the breathing control enable after completing a display from bright to dark); COM terminal breathing enable com_breath_en[x:0], used to indicate whether a certain COM terminal needs to breathe, and x depends on the number of COM ports specified in the design specification; SEG terminal breathing enable seg_breath_en[y:0], used to indicate whether a certain SEG terminal needs to breathe, and y depends on the number of SEG ports specified in the design specification.

[0043] It should be noted that all the configurable parameters mentioned above can be configured through registers. From the user's perspective, the above configurable parameters can be configured by writing registers. That is, users can control the grayscale change effect, speed and accuracy of the LCD screen by modifying the configurable parameters, in order to achieve a good visual experience and enhance the user experience.

[0044] like Figure 1 and Figure 2As shown, the initial values ​​of the first counter and the second counter are configured by the register configuration module lcd regs according to the configuration information transmitted from the outside. Among them, the maximum value of the count of the first counter is the total number of frames in the unit time total_frames, which is used to indicate a grayscale update cycle, and its initial value is configured to 0. The full count of the first counter is the counting condition of the second counter, but the second counter needs to be configured with different initial values ​​under different conditions to achieve different breathing effects. The initial value and counting result of the second counter depend on the breathing effect selection signal lcd_breath_effect, the breathing mode selection signal lcd_breath_mode and the frame number change step length disp_step. Under the gradually brightening and breathing effects, the initial value of the second counter is configured to 0, and under the gradually fading effect, the initial value of the second counter is the display frame number disp_frames in the unit time. In the single breathing mode, the second counter performs a complete increment or decrement (in the breathing mode, first increment and then decrement) operation and then clears to zero. In the continuous breathing mode, the second counter performs continuous increment or decrement operations, and can only be cleared after the breathing control is turned off by software. In addition, the values ​​of the first register and the second register are also configured by the register configuration module lcdregs according to the configuration information transmitted from the outside. Obviously, when one of the breathing enable of the COM terminal and the breathing enable of the SEG terminal is at a low level, the second data selector selects the original data for display without the breathing effect. Only when the breathing enable of the COM terminal and the breathing enable of the SEG terminal are both at a high level, can the intersection of a certain COM terminal and a certain SEG terminal be selected for grayscale control, thereby achieving the corresponding breathing effect.

[0045] Reference Figure 1 The comparator is used to compare the count values ​​of the first counter and the second counter in real time. In the embodiment of the present application, when the count value of the first counter is less than or equal to the count value of the second counter, the frame display enable signal is set to 1, and the image data at the corresponding moment is output normally. Otherwise, the frame display enable signal is set to 0, and the image data at the corresponding moment are all set to 0, and the screen does not display the image. The grayscale adjustment is achieved by changing the time for the LCD screen to display the pattern per unit time through the frame display enable signal. By using the principle of visual persistence, display effects such as gradual brightening, gradual fading, and breathing can be achieved.

[0046] As can be seen from the above, the liquid crystal screen controls the pixels by scanning. On this basis, the embodiment of the present application sets the COM end breathing enable and the SEG end breathing enable, which are used to indicate whether the intersection of a certain COM end and a certain SEG end needs to breathe. The number of register bits required for this scheme = the number of COM ports + the number of SEG ports, which occupies a small circuit area and can control a certain pixel to achieve a breathing effect. The disadvantage is that the control is not flexible enough and multiple pixels cannot be controlled separately at the same time. In another embodiment, a grayscale control enable bit is added separately for each pixel, that is, each pixel has a separate function of controlling the light and dark of the pixel and the function of controlling the breathing of the pixel. The number of register bits required for this scheme = the number of COM ports × the number of SEG ports, which has the advantage of accurate and flexible control, and the disadvantage is that it will take up more circuit area. Since most of the general dot matrix / segment code LCD screens are customized patterns, the first scheme is more practical.

[0047] Due to the special imaging principle of the LCD screen, it needs to be driven by AC voltage. The average voltage on the liquid crystal molecules in a complete frame must be 0, so the breathing enable cannot be turned on at any time to avoid voltage imbalance in the complete frame causing polarization of the liquid crystal molecules and damage to the screen. Therefore, it is necessary to control the timing of turning on and off the breathing enable. In one embodiment, if Figure 4 As shown in the figure, if the software turns on the breathing enable (breath_en) through the breathing enable set signal (set_breath) in the middle of a frame, the hardware will generate a preset signal (set_breath_pre), and the breathing enable (breath_en) will not be turned on until the frame end flag signal (frame_end_flag) is pulled high. It will take at most one frame time for the breathing enable set signal set_breath to be valid to the breathing enable breath_en to be set to 1. Similarly, if Figure 5 As shown, if the software turns off the breathing enable (breath_en) through the breathing enable clearing signal (clr_breath) in the middle of a frame, the hardware will generate a pre-clearing signal (clr_breath_pre), and the breathing enable (breath_en) will not be turned off until the frame end flag signal (frame_end_flag) is pulled high. From the effective breathing enable setting signal clr_breath to the breathing enable breath_en clearing 0, it will delay at most one frame time. The method described in the embodiment of the present application avoids damage to the LCD screen and prolongs the life of the LCD screen.

[0048] An embodiment of the present application also provides a chip and a screen, wherein the chip includes the screen driving circuit. The chip can be assembled in the screen (such as a liquid crystal screen), so that the liquid crystal screen can change the frame display enable signal by changing the total number of frames per unit time and the number of displayed frames per unit time, thereby changing the time for the liquid crystal screen to display a pattern per unit time to achieve grayscale adjustment. By utilizing the principle of visual persistence, display effects such as gradual brightening, gradual fading, and breathing can be achieved, so that grayscale control is no longer limited by the electrical specifications of the liquid crystal screen, greatly reducing the complexity of software control and having a good visual perception.

[0049] Obviously, the above-mentioned embodiments are only a part of the embodiments of the present application, rather than all the embodiments, and the technical solutions between the various embodiments can be combined with each other. In addition, if the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inside", "outside" and the like appear in the embodiments, the orientation or position relationship indicated is based on the orientation or position relationship shown in the accompanying drawings, which is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application. If the terms "first", "second", "third" and the like appear in the embodiments, it is to facilitate the distinction of related features and cannot be understood as indicating or implying their relative importance, order or number of technical features.

[0050] In addition, in the description of this application, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0051] Although the embodiments of the present application have been shown and described, it is understood by those skilled in the art that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present application, and the scope of the present application is limited by the attached claims and their equivalents. The above is only the preferred embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various changes and variations. Any modification, equivalent substitution, improvement, etc. made within the spirit and principle of the present application shall be included in the scope of protection of the present application.

Claims

1. A control circuit for screen display, characterized in that: The control circuit for screen display includes a first counter, a second counter, a comparator, a first data selector, a second data selector, a first AND gate, a second AND gate and a SEG terminal level selection signal generator, wherein: The first input end of the comparator is connected to the first counter, and is used to receive the total frame count value within a unit time output by the first counter. The second input end of the comparator is connected to the second counter, and is used to receive the display frame count value within a unit time output by the second counter. The comparator is used to compare the total frame count value within the unit time with the display frame count value within the unit time, and then transmit the comparison result to the address selection end of the first data selector through the output end of the comparator. The first data selector selects the corresponding preset signal as a frame display enable signal according to the comparison result output by the comparator and transmits it to the first AND gate, wherein the frame display enable signal is used to indicate whether the current frame needs to display an image; The first AND gate receives the frame display enable signal output by the first data selector and the externally transmitted liquid crystal screen display data and performs an AND operation, and then transmits the AND operation result to the first input terminal of the second data selector; The second AND gate receives the breathing enable of the COM terminal and the breathing enable of the SEG terminal and performs an AND operation, and then transmits the AND operation result to the address selection terminal of the second data selector; The second input end of the second data selector is used to receive the LCD screen display data input from the outside, and the second data selector selects the LCD screen display data or the AND operation result of the first AND gate as the input of the SEG terminal level selection signal generator according to the AND operation result output by the second AND gate; The SEG terminal level selection signal generator is used to generate a corresponding SEG terminal level selection signal according to the LCD screen display data or the AND operation result of the first AND gate, and the SEG terminal level selection signal is used to control the grayscale of the LCD screen.

2. A control circuit for screen display according to claim 1, characterized in that: The control circuit for screen display also includes a first register and a second register, wherein: The first register is connected to the first input terminal of the second AND gate, and is used to transmit the breathing enable of the COM terminal to the second AND gate. The second register is connected to the second input terminal of the second AND gate, and is used to transmit the SEG end breathing enable to the second AND gate.

3. A screen driving circuit, characterized in that: The screen driving circuit comprises the control circuit for screen display according to any one of claims 1 to 2, and the screen driving circuit further comprises a data reading module, a register configuration module and a driving control signal generating module, wherein: The data reading module and the register configuration module are respectively connected to the drive control signal generating module, the data reading module is used to read the LCD screen display data stored in the external display memory and transmit it to the drive control signal generating module, the register configuration module is used to configure the functional parameters of the drive control signal generating module, the drive control signal generating module is used to generate a COM terminal level selection signal and a SEG terminal level selection signal according to the LCD screen display data, wherein the drive control signal generating module includes the control circuit for screen display, and the SEG terminal level selection signal is used to control the grayscale of the LCD screen.

4. A screen driving circuit according to claim 3, characterized in that: The data reading module is connected to the first AND gate and the second data selector, and is used to read the LCD screen display data stored in the external display memory and transmit it to the first AND gate and the second data selector, wherein the control circuit for screen display includes the first AND gate and the second data selector.

5. A screen driving circuit according to claim 3, characterized in that: The register configuration module is connected to the first counter, the second counter, the first register and the second register, and is used to configure the functional parameters of the control circuit for screen display, wherein the control circuit for screen display includes the first counter, the second counter, the first register and the second register.

6. A screen driving circuit according to claim 3, characterized in that: The screen driving circuit includes a video memory control module, which is connected to the data reading module. The video memory control module communicates with the outside through an address bus and a data bus, and is used to control an external central processing unit to read and write external video memory, so that the data reading module can read the LCD screen display data stored in the external video memory.

7. A screen driving circuit according to claim 3, characterized in that: The screen driving circuit comprises a signal synchronization module, which is connected to the register configuration module and the driving control signal generating module and is used for synchronizing the system clock and the working clock of the screen driving circuit across time domains.

8. A screen driving circuit according to claim 3, characterized in that: The screen driving circuit includes an analog voltage generating module, which is connected to the driving control signal generating module and is used to output an analog voltage for driving the liquid crystal screen according to the COM terminal level selection signal and the SEG terminal level selection signal.

9. A chip, characterized in that: The chip comprises the screen driving circuit according to any one of claims 3 to 8.

10. A screen, characterized in that: The screen comprises the chip according to claim 9.

Images