KR20060032259A - LCD module interface device and method - Google Patents

Abstract

The present invention relates to an LCD module interface device and method for simultaneously supporting a multi vendor LCD module.

According to an aspect of the present invention, there is provided an LCD module interface device including: an LCD module including a timing controller and a gray scale unit for timing correction and gray scale voltage level correction of an LCD; An LCD interface unit for interfacing with the LCD module to support different types of LCD modules; When an arbitrary LCD module is mounted, the central processing unit automatically receives a signal for each LCD type according to the presence or absence of frame memory in the LCD module, detects the LCD type, and configures an interface with the LCD module according to the detected LCD type. And an LCD controller which outputs the LCD type data bus and control signals to the LCD interface to control the display of the LCD module.

LCD Modules, LCD Interfaces, Vendors, Frame Memory

Description

LCD module interface device and method {Apparatus and method for LCD module interface}

1 is a block diagram showing an LCD module interface device according to a first embodiment of the prior art.

Figure 2 is a block diagram showing an LCD module interface device according to a second embodiment of the prior art.

3 is a block diagram showing an LCD module interface device according to an embodiment of the present invention.

Figure 4 is a block diagram showing an example of the display mode in the LCD A module according to an embodiment of the present invention.

5 is a block diagram showing an example of the display mode in the LCD B module according to an embodiment of the present invention.

FIG. 6 shows an example of address and data for display of the LCD B module of FIG. 5; FIG.

Figure 7 is a flow chart for setting the driver power, LCD panel and gray scale values of the LCD B module according to the present invention.

8 is a voltage state transition diagram according to an embodiment of the present invention.

9 is a view showing a register initialization of the LCD B module according to the present invention.                 

10 is a flowchart showing an LCD B module interface method according to the present invention.

<Description of Symbols for Main Parts of Drawings>

110 Central processing unit 111 LCD control unit

121 ... LCD interface 130,140 ... LCD module

134,144 ... Timing control unit 135,145 ... Gray scale unit

141 Frame memory 142 Register

The present invention relates to an LCD module interface device and method for simultaneously supporting a multi vendor LCD module.

Recently, as the number of terminals to which the LCD module is applied increases, the type of terminal increases, and as the manufacturers vary, different types of LCD modules are applied to the main board of the terminal. To this end, the motherboard is equipped with components that can support heterogeneous LCD modules.

1 is a conventional LCD module interface device.

Referring to FIG. 1, a central processing unit 10, a plurality of timing controllers 11 and 12, a gray scale unit 13 and 14, an LCD interface unit 21, and an LCD module 22 may be included.

FIG. 1 is a case of supporting two companies' LCD modules (LCD_A or LCD_B) 22, and the timing controllers 11 and 12 and the gray scale units 13 and 14 to support different LCD modules 22. The main board (Main board, not shown) is mounted on each.

The central processing unit 10 controls the operation of the system and the display of the LCD, and depending on which LCD module 22 of the LCD A or LCD B module is mounted, through the corresponding timing controllers 11 and 12 to control the LCD frame. The timing is controlled, and the gray scale units 13 and 14 support gray scale values when the corresponding LCD module is mounted.

The LCD interface 21 displays the RGB signals, the data signals, the control signals of the central processing unit 10, and various signals applied from the timing controllers 11, 12, and the gray scale unit 13, 14. Interface with module 22.

1, the timing controllers 11 and 12 and the gray scale units 13 and 14 are separately installed outside the LCD module to support the different LCD modules (LCD_A or LCD_B) by the same type of LCD. It is possible to support a multi-vendor LCD that supports LCD modules of multiple vendors having an interface unit 21.

2 is another configuration diagram of a conventional LCD module interface device.

Referring to FIG. 2, a plurality of timing controllers 41 and 42 are mounted on a main board, and a gray scale unit (not shown) and an internal frame are installed inside each LCD module 52 mounted on the LCD interface unit 51. Frame memory 53 is built in.

The internal frame memory 53 buffers a signal in units of frames and outputs the same to the LCD. In order to support this, there are two methods of using RGB display data or accessing and displaying the frame memory 53 from the central processing unit 30.

The first method is to set the mode by accessing the initialization register to initialize the LCD at power-on when displaying in RGB data, and the memory bus of the central processing unit 30 must be connected to the LCD module 52 for this purpose. , The pin count of the LCD interface 51 is increased.

The second approach is to simplify the logic by accessing and displaying the frame memory built into the LCD, eliminating the need for an LCD control unit. However, there is a problem that system efficiency is lowered because the memory bus of the central processing unit 30 is used. These two methods only support a single LCD module, so it is disadvantageous in dealing with quantities.

Conventionally, there are the following problems.

In the LCD interface device as shown in FIG. 1, both the timing unit and the gray scale unit for gray scale voltage level and timing correction are installed in order to support the LCD modules of the two companies on the main board. There is a problem, and there is a problem that the price and installation space increases.

The LCD interface device as shown in FIG. 2 has a problem in that system efficiency is lowered because the memory bus of the central processing unit is connected to the LCD module. In addition, when displaying in RGB data, the memory bus of the central processing unit inevitably needs to be connected to the LCD, thereby increasing the pin number of the LCD interface, that is, the LCD connector.

It is a first object of the present invention to provide an LCD module interface device and method for sharing LCDs of different companies on a main board of a personal portable terminal.

It is a second object of the present invention to provide an LCD module interface device and method for automatically detecting a multi LCD vendor, configuring an interface according to an interface type of a corresponding LCD, and driving an LCD.

LCD module interface device according to the present invention for achieving the above object,

An LCD module including a timing controller and a gray scale unit for timing correction and gray scale voltage level correction of the LCD;

An LCD interface unit for interfacing with the LCD module to support different types of LCD modules;

When an arbitrary LCD module is mounted, the central processing unit automatically receives a signal for each LCD type according to the presence or absence of frame memory in the LCD module, detects the LCD type, and configures an interface with the LCD module according to the detected LCD type. And,

In order to control the display of the LCD module characterized in that it comprises an LCD control unit for outputting the data bus and control signals for each LCD type to the LCD interface unit.

Preferably, the central processing unit is connected to the LCD module and the first and second general-purpose input and output terminals through the LCD interface unit, and automatically detects the corresponding LCD type according to the presence or absence of a frame memory through the first general-purpose input and output terminals. And, if there is a frame memory in the LCD module, it characterized in that to output a signal for controlling the operation mode of the LCD module through the second general-purpose input and output terminals.

Preferably, since the central processing unit has an internal frame memory in the LCD module through a second general-purpose input / output terminal, a first operation mode for initializing a register and a display for the display of the LCD module when the first operation mode ends. And switching to the second operation mode.

Preferably, the LCD control unit outputs an RGB signal through a data bus and outputs a dot clock signal as a control signal for the LCD module having no frame memory therein.

Preferably, the LCD control unit initializes a register using a bit and a control signal of a data bus for an LCD module having a frame memory therein, and controls the display by using a data bus and a control signal when the register initialization is completed. Characterized in that.

LCD module interface method according to an embodiment of the present invention,

If the LCD module is equipped with an LCD interface, detecting an LCD type signal from the LCD module;                     

When the LCD type signal is detected and an LCD module having an internal frame memory is mounted, initializing a register of the corresponding LCD module and controlling the LCD display when the register initialization is finished;

And detecting the LCD type signal to control the LCD display when the LCD module does not have an internal frame memory.

Preferably, the register initialization of the LCD module having the internal frame memory, after the central processing unit is set to the register initialization mode to the general-purpose input and output terminals, and transmits the address and data for the initialization of the register to some bits of the data bus, It is characterized by initializing registers in the module.

The LCD module interface device according to the present invention will be described with reference to the accompanying drawings.

3 is an embodiment of the present invention.

Referring to FIG. 3, a central processing unit 110 having an LCD control unit 111 and an LCD interface unit 121 are provided to support different LCD modules 130 and 140.

The central processing unit 110 controls the LCD driving through the LCD interface 121 through the data bus and the control signal line of the LCD control unit 111, and recognizes the type (LCD TYPE) of the LCD module (130, 140) And a plurality of general purpose input / output pins (GPIOs) for controlling the mode.

Here, the supportable LCD modules 130 and 140 are, for example, the LCD A module 130 or the LCD B module 140. The LCD A module 130 has no internal frame memory and has a timing controller 134 and a gray scale unit 135 as shown in FIG. 4. The LCD B module 140 includes an internal frame memory 141 and a register 142, and has a timing controller 144 and a gray scale unit 145 embedded therein as shown in FIG. 5.

The central processing unit 110 receives the LCD type (LCD A or LCD B) through the second general-purpose input / output terminal (GPIO2), and controls the operation mode of the LCD module through the first general-purpose input / output terminal (GPIO 1). do.

The LCD control unit 111 outputs an RGB signal and a data signal through a data bus according to the LCD type, and outputs corresponding control signals according to the LCD type. Here, the LCD control unit 111 may be integrally configured with the central processing unit or may be separately configured externally.

An operation when the LCD A module 130 is mounted will be described with reference to FIGS. 3 and 4. The LCD A module 130 is a module without a frame memory therein.

When the LCD A module 130 is mounted, the central processing unit 110 receives the LCD type (LCD_TYPE) signal through the second general-purpose input / output terminal GPIO 2 connected to the LCD A module 130. In this case, the second general-purpose input / output terminal GPIO 2 is an input / output terminal for selecting an LCD vendor. When the LCD module 130 does not have an internal frame memory, the second general-purpose input / output terminal GPIO 2 receives a high signal and has an LCD module having an internal frame memory 141 ( In case of 130), a low signal is received. According to the LCD type reception signal H / L of the second general-purpose input / output terminal GPIO 2, a software driver suitable for the LCD vendor and type is configured.                     

The LCD controller 111 outputs the RGB signal to the LCD A module 130 through the LCD interface 121 and displays the data through the data bus. At this time, the LCD control unit 111 outputs a dot clock signal DOTCLK and a data enable signal DE as a control signal line.

That is, when the LCD type signal LCD_TYPE is applied as the "high signal", the central processing unit 110 does not use the operation mode signal because the LCD A module 130 is mounted and does not use RGB through the data bus line. A signal is output, and a dot clock signal and a data enable signal are output through the control signal line to drive the LCD A module.

Here, when the LCD A module 130 is displayed, only the dot clock signal necessary for display timing is used, and the horizontal synchronizing signal HSYNC and the vertical synchronizing signal VSYNC are not used.

Meanwhile, the LCD B module interface device will be described with reference to FIGS. 3 and 5 as follows. Here, the LCD B module has a configuration in which an internal frame memory exists.

When the LCD B module 140 is mounted, the central processing unit 110 recognizes that the frame memory 141 is present inside the LCD module 140 when a low signal is applied from the second general-purpose input / output terminal GPIO 2. do. Accordingly, the operation mode control signal is output to the LCD B module 140 through the LCD interface 121 through the first general-purpose input / output terminal GPIO 1.

At this time, the operation of the LCD B module 140 is switched to the CPU mode and the RGB mode by the signal output from the first general-purpose I / O terminal GPIO 1. That is, when the operation mode signal output to the first general-purpose input / output terminal GPIO 1 is “low” (MODE: L), the LCD B module 140 operates in a CPU mode that initializes the register 142. If "High (MODE: H)", the initialization of the register 142 is finished and the operation is controlled in the RGB mode to display the LCD.

As shown in FIGS. 3 and 9, the initialization of the register 142 is performed in the CPU mode. A low signal (LCD_TYPE: L) is input to the second general-purpose input / output terminal GPIO 2, and the first general-purpose The high signal MODE: H is output to the input / output terminal GPIO 1. At this time, the LCD control unit 111 sends the initialization code data of the register 142 through the data bus line.

At this time, before initialization of the LCD B module, n / 2 bits of the RGB n-bit data lines are converted to the GPIO mode to send the register initialization code to initialize the register 142. This is because the LCD module 140 having the internal frame memory 141 supports the n / 2-bit interface due to the interface characteristics of the central processing unit 110. Therefore, when initializing, the first n / 2 bits of the data are repeated twice. The address, later n / 2 bits, will send the data. Here, when n bits are 16 bits, an address and data are sent to 8 bits.

That is, as shown in (a) and (b) of FIG. 6, in order to initialize the register 142 of the LCD module, addresses and data are sequentially sent to 8 bits D0 to D7 of the data bus to be initialized.

The LCD controller 111 outputs a write and read signal of the internal frame memory 141 through a control signal line, and selects a chip select signal CS # and a source driver for selecting the internal frame memory 141. Reset signals such as a driver and a gate driver are sent. That is, when the register is initially reset by the CPU mode (RESET #: LOW) during the register initialization, the write signal (WR #: LOW) writes data to the register while the chip select signal (CS #: LOW) is active. The read signal RD # is used to read data written to the register.

FIG. 7 is a flowchart of setting power, LCD panel, and gray scale values of a driver (Gate, source driver, etc.) inside the LCD by the register initialization code.

As shown in FIG. 7, the operation is sequentially performed in a CPU mode S110 for initializing a register and an RGB mode S120 for display.

When the LCD module is powered on in the CPU mode (S110) (S111), the source driver and the gate driver for driving the LCD module are reset in the initial power-on step (S113). In the next power-on step, various power supply voltages VDD2, VR1 and VDD1, VSS4, VR2 and VSS3, VCOM, and VS are turned on (S115).

Here, the various power supply voltages of the LCD module are output pins of VDC * 2 (VDD2) as output pins for power supply, and VR1 is a step-up circuit as shown in FIG. For the output pin of the reference voltage. VDD1 is the positive voltage output pin for the gate raster low drive circuit. VSS4 is the negative voltage, output pin for the gate raster drive circuit. VR2 is the output pin of the reference voltage for step-up circuit 4. VCOM is the power supply for the electrodes of the LCD. VS is the power supply of the source driver unit.

Here, the power-on sequence is supplied in the order of VDC> VDD2> VR1> VDD1> VSS4> VR2> VSS3> VCOM> VS as shown in FIG.

Thereafter, the LCD panel is set (S117), and the CPU mode is terminated by performing gamma adjustment (S119).

When the CPU mode ends, the CPU operates in the RGB interface mode (or RGB mode), and the RGB mode (S120) performs the display mode and the internal capture mode (S121). Here, the internal capture mode is a mode in which data is stored in the internal frame memory and then displayed.

Meanwhile, in the RGB mode, the LCD control unit 111 sends an RGB signal to an n-bit interface (for example, 16 bits) for the LCD display. When the RGB mode is displayed, the necessary RGB signal is output while the register initialization is completed and the RGB mode is switched.

The LCD control unit 111 outputs a dot clock DOTCLK, a horizontal synchronizing signal HSYNC, and a vertical synchronizing signal VSYNC necessary for the LCD display timing through the control signal line.

10 is a flowchart illustrating an LCD module interface method according to the present invention.

If any LCD module is mounted on the LCD interface unit (S131), the first and second universal input and output terminals are connected between the LCD module and the central processing unit. At this time, when the LCD type signal is received through the second general-purpose input / output force terminal, it is recognized whether the LCD internal frame memory is present or not, and sets the mode to the LCD module according to the recognized LCD type (S133 and S135).

At this time, it is checked whether there is a frame memory in the LCD module (S137). If there is a frame memory in the LCD module, the controller module operates in the CPU mode of the LCD module to initialize the register (S139). Operation in the RGB mode allows the LCD display (S141).

If there is no frame memory inside the LCD module, the display driving of the LCD module is controlled (S143).

As such, even when different types of LCD modules are mounted on the LCD interface, the timing controller and the gray scale unit may be embedded in each LCD module, and the interface of each LCD module may be enabled according to the presence or absence of an internal frame memory.

So far, the present invention has been described with reference to the preferred embodiments, and those skilled in the art to which the present invention pertains to the detailed description of the present invention and other forms of embodiments within the essential technical scope of the present invention. Could be implemented. Here, the essential technical scope of the present invention is shown in the claims, and all differences within the equivalent range will be construed as being included in the present invention.

As described above, according to the LCD module interface device according to the present invention, the timing controller and the gray scale unit are integrally integrated in the LCD module, thereby providing an excellent space and price competitiveness of the substrate.

In addition, the LCD module without the internal frame memory is displayed using a data bus, and the LCD module with the internal frame memory can be initialized with a register using the data bus and then switched to the display mode. All modules can be supported, which can solve the problem of mass production.

Claims (7)

An LCD module including a timing controller and a gray scale unit for timing correction and gray scale voltage level correction of the LCD; An LCD interface unit for interfacing with the LCD module to support different types of LCD modules; When an arbitrary LCD module is mounted, the central processing unit automatically receives a signal for each LCD type according to the presence or absence of frame memory in the LCD module, detects the LCD type, and configures an interface with the LCD module according to the detected LCD type. And, And an LCD controller which outputs the LCD type data bus and control signals to an LCD interface to control the display of the LCD module. The method of claim 1, The central processing unit is connected to the LCD module and the first and second general-purpose input and output terminals through the LCD interface unit, and automatically detects the corresponding LCD type according to the presence or absence of frame memory through the first general-purpose input / output terminal. The LCD module interface device, characterized in that for outputting a signal for controlling the operation mode of the LCD module through the second general-purpose input and output terminal when there is a frame memory inside the module. The method of claim 1, The central processing unit has an internal frame memory in the LCD module through a second general-purpose input / output terminal, and thus, a first operation mode for initializing a register and a second operation for display of the LCD module when the first operation mode ends. LCD module interface device characterized in that to switch to the mode. The method of claim 1, And the LCD control unit outputs an RGB signal through a data bus to an LCD module having no frame memory therein, and outputs a dot clock signal as a control signal. The method of claim 1, The LCD control unit initializes a register by using a bit and a control signal of a data bus for an LCD module having a frame memory therein, and controls the display by using a data bus and a control signal after initialization of the register. LCD module interface device. If the LCD module is equipped with an LCD interface, detecting an LCD type signal from the LCD module; When the LCD type signal is detected and an LCD module having an internal frame memory is mounted, initializing a register of the corresponding LCD module and controlling the LCD display when the register initialization is finished; And controlling the LCD display when the LCD type signal is detected and the LCD module does not have an internal frame memory. The method of claim 6, In the register initialization of the LCD module having the internal frame memory, the central processing unit sets the register initialization mode to the general-purpose input / output terminal, and then transfers the address and data for initializing the register to some bits of the data bus, LCD module interface method, characterized in that to initialize the register.

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