JPH09128182A - Display unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a display system with a display adapter which is latently compatible with various unlimited display devices by providing a nonvolatile memory(NVM) which stores display information in a digital code form. SOLUTION: This device is provided with the nonvolatile memory 9 which is arranged on the display device 88 and stores extension control data in plural control codes and communication logic 95 which communicates the control codes between the memory and an output port 94 in response to a command signal generated by a display adapter circuit 92. Control data like important signal timing matters of a new display device can be stored in the form of digital control code held in the memory of the display device, so the programming of the display system has the advantage that the program need not be updated each time a different display device is connected to the output port.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a display system in which control data (data including timing parameters for generating a video signal and a synchronization signal) is communicated between a computer system and a display device.

[0002] The control data includes parameters for defining the shape and resolution of an image displayed on a display device.
In a display system consisting of a raster scan display device, such as a cathode ray tube (CRT) display device, the parameters are the horizontal and vertical scan signals generated to provide the raster scan by electrical circuitry in the display device. Speed and amplitude. To generate an image, a scan signal is synchronized with a video signal from a video source, such as a computer system, by a synchronization pulse also generated by the video source.

[0003]

BACKGROUND OF THE INVENTION Certain display devices can only operate in a single display mode according to a single set of parameters. Other display devices can be configured to operate in any of a number of display modes characterized by various sets of parameters. The latter is hereinafter referred to as a multi-mode display device. For display devices controlled by a computer system, it is preferred that the computer system identify the type of display device so that the appropriate video and synchronization signals can be generated. Various examples of such computer systems, including the IBM PS2 range, include a video graphics adapter (VGA adapter) having an output port for connecting video and synchronization signals to a display device. The VGA adapter also has logic responsive to the manner in which the identification pin of the output port is terminated when connected to a display device. This logic identifies the type of display device connected from these terminals to the VGA adapter.

[0004] GB 2,162,026 describes an example of a display system employing a multi-mode display device that receives video and synchronization signals from a display adapter of a computer system. The display device can operate in any of four display modes. The computer system can be commanded to provide a positive or negative polarity sync pulse. Each polarity combination indicates a different display mode. The display device includes decoding logic that configures the display device to operate in a particular display mode in response to a predetermined synchronization pulse polarity.

In the prior art display systems, the prior art display interface has the disadvantage that only a limited number of different display devices can be identified and therefore only the appropriate control signals can be generated. The reason for this limit is that the number of pins available for display device identification and control is limited by the physical form of the output port.

[0006]

Accordingly, it is an object of the present invention to provide a display system having a display adapter that is potentially compatible with a variety of display devices without limitation.

[0007]

SUMMARY OF THE INVENTION According to the present invention, in response to a plurality of data signals defining data to be displayed (signals transmitted from a display adapter circuit to a display device and containing data actually displayed on a display). A display device for generating a visual output; a display adapter circuit for generating a data signal in a form defined by control data unique to the display device; and a display device for transmitting a data signal from the display adapter circuit to the display device. And an output port for connecting control data from the display device to the display adapter circuit, the control device being arranged on the display device, and a plurality of control codes (control data being stored in a nonvolatile manner). The byte stored in memory in 16-bit format A non-volatile memory for storing extended control data in the form of a recode) and a command signal (a communication command for the display adapter circuit to exchange signals with the display device) generated by the display adapter circuit. A display system is provided, further comprising communication logic for communicating control codes between the memory and the output port. This means that the programming of the display system can be done because the control data, for example the signal timing requirements of any new display device, can be stored in the form of digital control codes held in the memory of the display device. Has the advantage that no update is required each time another display device is connected to the output port. Alternatively, the display adapter can read new timing requirements from the new display device's memory in order to generate video and synchronization signals to accurately drive the new display device.

The communication logic includes a serial data link for communicating a control code between a display device and an output port; a device control logic for communicating a control code between a memory and a serial data link; Adapter control logic for communicating control codes between the link and the display adapter circuit may be included. This has the advantage that if the display system includes a multi-mode display device, the display adapter circuit can use a serial data link to configure the display device to operate in the desired display mode.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the accompanying drawings. FIG. 1 shows an example of a computer system incorporating a display system having a CRT display device 88.

[0010] The computer system includes a central processing unit (CPU) 80 for executing the programmed instructions.
including. Bus architecture 86 provides data communication between CPU 80 and other components of the display system. Read-only memory (ROS) 81 securely stores data. The random access memory 82 temporarily stores data. Host computer system 9
3 is provided by a communication adapter 85. I / O adapter 84 allows data to pass between bus architecture 86 and peripheral devices such as disk file 83. The user can operate the bus architecture 86 using the keyboard adapter 90.
The computer system can be operated using the keyboard 91 connected to the. CRT display device 88 provides a visual output from the display system. Display adapter 92 generates a video signal and a sync signal at output port 94 to enable display device 88 to generate a visible output.

According to the present invention, the display device 88
Includes a non-volatile memory (NVM) 9 for storing display information in the form of digital codes. Display information is communicated between display device 88 and display adapter 92 along serial link 3 controlled by communication logic 95. Serial link 3 is separate from the lines that carry video and synchronization signals from display adapter 92 to the display device.
Communication logic 95 is divided into adapter logic 96 and device logic 97. In operation, adapter logic 96 initializes both commands to read data from and write data to NVM 9, and device logic 97 responds accordingly.

The communication logic 95 will be described below in detail with reference to FIG. Adapter logic 96 includes device driver 1 that generates command code 21 in response to program instructions. First parallel-to-serial converter 2 (serializer)
Command code 21 so that the first line driver 4 communicates to the device logic 97 along the serial link 3.
To a command bit stream 22. The device logic 97 includes a second receiver 5 for detecting the command bit stream 22. The second serial / parallel converter 6 (deserializer) converts the command bit stream 22 back to the command code 21. The command decoder 7 decodes the command code 21 into the NVM address 8.
The address space in NVM 9 is personality NVM
10 and a program NVM11.

The personality NVM 10 includes an identification code that provides the display system 88 with the specifications of the display device 88 connected to the display adapter 92. Each identification code is stored at a different address location. The identification code includes coded timing parameters that allow the display adapter 92 to generate the appropriate video and synchronization signals.
Specifically, the timing parameters include a sync pulse width, an active video period and a blanking interval. Also, the identification code preferably includes coded transfer parameters to indicate the maximum rate at which device logic 97 can read and write data from serial link 3. By reading the transfer parameters before issuing any other commands, the adapter logic 96 causes the data between the display device 88 and the display adapter 92 to be at a rate at which data is subsequently compatible with both the adapter logic 96 and the device logic 97. To ensure that they are forwarded. Each timing parameter is stored in the form of a 16-bit identification code. Fifteen bits of the code define the value of the timing parameter, and the sixteenth bit defines the polarity. The less important timing parameter is 8
It can be stored in the form of codes with less than bits. The personality NVM stores several sets of timing parameters corresponding to various display modes of the display device.

The program NVM 11 stores a control code for instructing a display input / output (I / O) circuit 12 to adjust a drive signal generated by a drive circuit 13 of the display device. This example of a drive signal directly affects the height, width and brightness of the visual output from the display device 88. Each control code is stored at a different address location. The display I /
By commanding the O-circuit 12, the display device 8
The eight visual outputs can be switched between various display modes controlled by a computer program.
Preferably, program NVM 11 also stores control codes that instruct display I / O circuit 12 to generate sample code representing the magnitude of the drive signal at a given node of drive circuit 13. It will be appreciated that this control code can be used to automate a diagnostic method to test the operation of the display device 88 after manufacturing or repair.

When adapter logic 96 issues a read command, device logic 97 responds by placing the appropriate response code 23 on serial link 3. The response code 23 may be an identification code 20 from the personality NVM or a sampled data code 19 from the display I / O circuit 12, depending on the nature of the read command. To perform such a response, device logic 97 includes parity logic 14 for adding a parity bit to response code 23. A second parallel-to-serial converter 15 converts the response code 23 into a response bit stream 24. The response bit stream 24 is placed on the serial link 3 by the second line driver 16. In the display adapter 92, the first receiver 17 transmits the response bit stream 24 over the serial link 3.
Is detected. The first serial-to-parallel converter 18 converts the detected response bit stream 24 back into a response code 23, which is decoded by the device driver 1.

The first parallel-to-serial converter and the first serial-to-parallel converter of the adapter logic can be combined in a single integrated circuit module, the second parallel-to-serial converter and the second serial-to-parallel converter. A similar module can be used to perform The first line driver and the first receiver can also be integrated into a single integrated module and of a similar driver / receiver to implement the second line driver and the second receiver Modules can be used.

[0017] Adapter logic 96 may be configured to receive a response from device logic 97 in either a "handshaking" mode or a "data streaming" mode. In "handshaking" mode, device logic 97 waits for the adapter logic to place an acknowledgment code on serial link 3 before sending out the next byte of the response. In "data streaming" mode, device logic 97 waits for adapter logic 96 to confirm that it will receive a block of bytes of the response before sending the next block.

One example of the present invention is a display adapter 9
Communication logic 95 including a serial link 3 separate from the lines carrying video and synchronization signals from 2 to the display device has been described where display information is communicated between display adapter 92 and display device 88. However, it is recognized that other communication links and coding methods may be used. Further, examples of the present invention include a raster scanning display device. It will be appreciated that the invention is equally applicable to other display devices such as, for example, liquid crystal display devices or vector scan display devices.

[Brief description of the drawings]

FIG. 1 is a block diagram of a computer system incorporating a display system including a display device.

FIG. 2 is a block diagram of communication logic for communicating display information between a display adapter and a display device.

[Explanation of symbols]

 3 Serial link 9 Non-volatile memory 88 Display device 92 Display adapter 94 Output port 95 Communication logic 96 Adapter logic 97 Device logic

Claims (8)

[Claims] A display device (8) connected to a display adapter circuit (92) of a computer system.
8) A display device having means for generating a visual output in response to a plurality of data signals generated by a display adapter circuit (92), wherein the plurality of control codes identify the display device (88). A memory (9) for storing control data in a format; and a command signal (21) from the display adapter circuit (92) for reading a control code from the memory (9) and transmitting the control code to the display adapter circuit (92). Device logic means (97) responsive to the display device. 2. The display device according to claim 1, wherein the display device includes a serial data link for communicating control codes between the display device and a display adapter logic circuit. 3. A receiver, wherein the device logic receives a command bitstream (22) from the adapter logic circuit along the serial data link, and a command signal (21) for the command bitstream (22).
, A command decoder for converting the command signal (21) into a memory address to access the stored control code, and a second parallel-to-serial conversion for converting the control code into a control bit stream. 3. The display device of claim 2, further comprising a device and a line driver connected to communicate a control bit stream along the serial data link to the adapter logic circuit. 4. The display device according to claim 3, wherein the parallel / serial converter and the serial / parallel converter are combined in a single integrated circuit module. 5. The display device according to claim 3, wherein the line driver and the receiver are incorporated in a single integrated circuit module. 6. The apparatus further comprising means for configuring the display device to operate in various display modes in response to mode control signals communicated from the adapter logic circuit to the device logic along the serial data link. The display device according to claim 2, wherein: 7. The display device further comprises means for adjusting operating parameters of a drive circuit of the display device in response to a parameter control signal communicated from the adapter logic circuit to the device logic along the serial data link. The display device according to claim 2 or 6, wherein 8. A device for acquiring digital samples of a signal at a node of the drive circuit and responding to a data request signal communicated from the adapter logic circuit to the device logic along the serial data link. The display device of claim 7, further comprising means for communicating the digital samples along the serial data link to the adapter logic circuit.