JPH03179493A - Display device - Google Patents

Abstract

PURPOSE:To make a fast display which does not depend upon a system bus by employing constitution wherein no load is applied on the system bus in the writing processing and reading processing of bit map data to and from a display memory. CONSTITUTION:This device includes a display-only main control means 101 which controls the whole device through a dedicated bus 108, a host interface 102 for a communication with a host computer 2, a work memory 103 that the main control means 101 uses, an expanding means 104 for compressed image data from the host computer 2, and the display memory 105 for data. Further, the device includes a read control means 106 which controls a read of data from the display memory 105 and a D/A converter 107. Then when an applica tion program on the computer displays data, a program dedicated to access to the display memory is used and run on the display device. Consequently, the display operation which does not depend upon the system bus of the host computer is speeded up.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to display devices used in computer systems, such as workstation systems.

Conventional technology Recently, there has been a demand for the development of applications that handle natural images, Ca images, etc. on workstations, and although some dedicated systems have already been realized (printing and prepress systems), general-purpose Implementation on a workstation is desired.However, there are several functional issues with current general-purpose workstations.

The hardware configuration of a conventional general-purpose workstation will be explained based on FIG.

This type of workstation has a main control unit (CP
The system bus 708 managed by U) 701 includes main memory C main memory l 702 , display memory 705 ,
A configuration is adopted in which units such as the auxiliary storage device 703 are connected. The transfer capacity of the system bus 708 is not substantially high because a bus [1 is generated by each unit access, and the display memory 705 is also approximately 8 bits/pixel (256 colors).

In addition, window systems that provide an excellent development environment due to the construction of a man-machine interface have recently become mainstream, with emphasis on network transparency, and those that adopt a server/client system have become mainstream. This method is
Each application program called a display memory does not access the display memory directly, but via a program called a dedicated server, and the client sends a drawing request to the server in the form of a message.

Using this method, for example, when displaying image data,
As shown in FIG. 88, the client reads data from the storage device 801, transmits it to the server, and the server draws data on the display memory 802. In this case, the server and client will hold the same bitmap data in different memory spaces even though they are on the same machine.

Problems to be Solved by the Invention Incidentally, in order to handle natural images, C0 images, etc., a full color display of about 24 bits/pixel is desirable, and in the above-mentioned general-purpose workstation, expansion of the display memory is essential. Furthermore, in the configuration shown in FIG. 7, the system bus is used when transferring data to the display memory, so as the amount of data to be transferred increases, it is also necessary to improve the transfer capacity of the system bus.

However, changing the system bus is not easy because it affects the entire workstation.

In addition, window systems based on the server/client method repeat message communication every time they are drawn, resulting in problems with communication overhead, making them unsuitable for communicating large amounts of data, and making it difficult to handle bitmap data, especially color natural images. Rarely.

Furthermore, during communication, the server and client store the same message (including bitmap data) in separate memory spaces.
It was inefficient to maintain the

In addition, some workstations dedicated to GalleyFox have been developed that have J[ system buses, but when communicating via a network, the problem of communication overhead is the same even with workstations that have high-speed system buses.

In view of this, the present invention provides a high-speed display device that does not depend on the system bus by adopting a configuration that does not place a load on the system bus when writing and reading bitmap data to the display memory. With the goal.

Another object of the present invention is to provide a display device that can reduce the communication load by transferring bitmap data between a server and a client as compressed data, and can also be used on a network.

Furthermore, by adopting a configuration in which the server and client can share memory, communication is realized by copying pointers on the shared memory, realizing efficient and high-speed server/client communication.

Means for Solving the Problems In order to solve the above problems, the display device of the great invention includes: l main control means for controlling the entire device via a dedicated bus; a host interface for communicating with the computer;
a work memory used by the main control means; a decompression means for decompressing compressed bitmap data from the computer; a data display memory; and a succession control for reading data in the display memory in synchronization with a display screen. and a D/A converter for converting digital data read from the display memory into an analog signal, and an application program c (hereinafter referred to as a client) on the computer displays data. This is done through a dedicated program (hereinafter referred to as server) that accesses the memory, and this server is operated on the display device.

Further, the display device of the great invention is equipped with a bitmap data compression means in the device, and in response to a request from a client to read data from a display memory, bitmap data is communicated from the server to the client using compressed data. This is how it was done.

Furthermore, the display device of the great invention uses a shared memory that can be accessed by both the server and the client as a host interface, and performs data communication between the server and the client using the pointer address of the data on the shared memory. This is how it is done.

Effects According to the above configuration, the display device of the workstation is made independent of the system bus on the host side, and by having a high-speed bus and decompression means in the display device, a small amount of compressed data can be transferred from the system bus on the host side. By decompressing and transferring actual image data within a display device that has a high-speed bus, it is possible to achieve high-speed display that does not depend on the system bus on the host side. In addition, by providing compression means within the display device, even when reading display memory data, a small amount of compressed data is transferred to the system bus on the host side, realizing read processing that reduces the load on the system bus. can do. In addition, by running the server program within the above-mentioned display unit and transferring bitmap data between the server and client as compressed data, the communication load can be reduced, and natural images can be displayed and read out via a network. It becomes possible. Furthermore, by having a shared memory between the server and the client, data communication between the server and the client can be performed using the pointer address of the data in the shared memory, which not only speeds up communication but also reduces memory usage. Effective use becomes possible. Further, even if the bitmap data is not compressed data, the communication load can be reduced.

Embodiments FIGS. 1 to 6 show block diagrams of workstations in each embodiment of the invention. In each block diagram, a server program runs on a display device and communicates messages with a client on the host side. A configuration is adopted in which the display memory within the display device is accessed while performing the display.

Hereinafter, an embodiment of the great invention A47) will be described based on FIG. In the display device shown in FIG. 1, the display function of the workstation is made independent from the host (system bus) side, and the display data transferred from the client on the host side is compressed data.

In the figure 'r141, l is a display device, on which the Windows server program is operated. 2 is a host computer (for example, a workstation) that does not have a display function
So 1. The client program is run.

The display device 1 includes a display-only main control means 101 that controls the entire device via a dedicated bus 108, and a host interface 10 that communicates with the host computer 2.
2 and a work memory 103 used by the main control means 101
, a decompressing means 104 for decompressing (decoding) compressed image data from the host computer 1, a data display memory 105, a read control means 106 for controlling reading of data from the display memory 105, and the display memory. 1
05, and a D/A converter 107 that converts the digital data read from 05 into an analog signal.

Here, the configuration of the host computer 2 will be explained. This host computer 2 has a system bus 20
A main control unit 201 that controls the entire computer via 5
, a main memory device C (hereinafter referred to as main memory) 202, an auxiliary memory device 203, and an external interface 204 for connection with the display bag @1.

Hereinafter, the operation of displaying compressed image data using the display device shown in FIG. 1 will be explained step by step.

(Step 1): The client program in the host computer 2 stores the compressed image data in the auxiliary storage device 203.
Read from. The read data is typically stored in main memory 202 within the host.

(Step 2): The client program sends the read image data to the server for display. Specifically, the system a section 201 of the host computer 2 writes a drawing message to the external interface 204, and upon receiving this, the display-only main control means 101 writes this message to the work memory 103 via the host interface 102. At this time, the display-only main control means 10
1 supports interrupt processing, it is also possible to perform message reception as interrupt processing.

(Step 3): The display-only main control means 101 analyzes the received message and instructs the decompression means 104 to start decompression processing. In a non-embodiment, it is assumed that the decompression means 104 itself has a function of reading data.

Therefore, the display-only main control means 101 has 6ζ
The pointer address of the compressed data in the work memory 103 is passed to the decompression means 104.

(Step 4): The decompression means 104 uses the work memory 10
The compressed data in 3 is sequentially read out and decompressed. Here, it is assumed that the decompressing means 104 has a local memory that holds decompressed data C (hereinafter referred to as decompressed data). Furthermore, the compression method is considered to differ depending on the data type, and must be defined in advance between the server and client. For binary data, compression methods used in facsimiles (such as MH1 kite) are used, and for multi-value data, DCT is used.
There are methods such as orthogonal transform coding, block coding, vector quantization, etc.

(Step 5): The display-only main control means 101 transfers the decompressed data in the decompression means 104 to the display memory 105 while calculating an overlapping area based on the window management information held by the window server.

At this time, if the memory for storing all the expanded image data in the decompression means 104 is empty, the decompression means 104 performs decompression processing for each size that can be stored, and the display-only main control means 1
01 will transfer (as hardware,
This method is common).

Note that in FIG. 1, the host interface 102 of the display device 1 is connected to the bus buffer C host interface 1.
There are two possible cases: 02 is directly connected to the system bus 205) and a network interface (such as Ethernet). When a network interface is used, the external interface 204 of the host computer 2 is also the same interface, and the display device is positioned as a window server terminal via the network of the host computer 2. Further, if the server program also manages input means such as a keyboard and a mouse, the display device 1 side is provided with the input means.

According to the above-mentioned unimplemented example, the display device is configured independently from the host computer, and the bit muff data transfer between the host computer and the display device when displaying an image is performed as compressed data, so that the display device is not dependent on the system bus of the host computer. This makes it possible to speed up the display of data without having to use it, and to reduce the communication load when bitmap data is transferred between the server and the client.

Next, a second embodiment will be explained based on FIG. 2.

The display device shown in FIG. 2 is such that a dedicated bus is provided between the work memory that stores communication data from the client and the decompression means, and the decompression processing and the reading processing of the decompressed data are performed in a pipeline. .

In the embodiment shown in FIG.
Bus collisions occurred due to the use of , and processing was performed sequentially under bus arbitration.

On the other hand, as shown in FIG.
By providing a dedicated bus 109 between the decompressing means 104 and the decompressing means 104, the decompressing means 104 does not need to access the internal bus 108 of the display device. The means 104 can perform the next decompression process in parallel. In other words, step 4 and step 5 in the embodiment of FIG. 1 can be operated in parallel.

Therefore, according to this embodiment, it is possible to perform decompression processing and display in a pipeline, and speed up the decompression and display processing.

Next, a third embodiment will be described based on FIG. 3.

The display device shown in Figure 3 has the display function of the workstation independent from the host C system bus), and image data is compressed and transferred from the server on the display device to the client on the host. It is something.

In FIG. 3, the host computer 2 is the same as that in the embodiment of FIG. 1, but the display device 1 according to this embodiment
is equipped with a compression means 110 that reads designated area data in the display memory 105 and performs compression processing.

Hereinafter, questions will be asked step by step regarding the operation of reading compressed image data from the display memory using the display device shown in FIG.

(Step 1): The client program of the host computer 2 sends an instruction to read data from the display memory 105 to the server. Whether or not read data should be compressed may be specified by the client or unconditionally compressed by the server. This is the server/
It is sufficient to define the command contents between clients in advance.

(Step 2): The display-only main control means 101 analyzes the received data message and stores it in the display memory 1 in the compression means 110.
Commands to start compressed reading of data in 05.

In this embodiment, it is assumed that the compression means 110 has a function of reading arbitrary area data in the display memory 105. Therefore, at startup, the display-only main control means 101 instructs the coordinate address of the readout area.

(Step 3): The compression means 110 reads the designated area data on the display memo 105 and performs compression processing. At this time, the compression means 110 compressed data C and below,
It is assumed that the computer has a local memory that stores compressed data (referred to as compressed data).

(Step 4): The display-only main control means 101 reads the compressed data from the compression means 110 into the work memory 103. At this time, if there is no memory in the compression means 110 to store all the compressed image data, the compression means performs compression processing for each size that can be stored, and the display-only main control means 101 transfers this to the work memory 103. It turns out (
This method is common for hardware).

(Step 5): The display-only main control means 101 is! ! The generated compressed data is sent to the client via the host interface 102.

As described above, according to the present embodiment, in the process of reading image data from the display memory 105, it is possible to transmit it as compressed data from the server to the client, and in the process of reading image data from the server, bits between the server and the client can be transmitted. The communication load during map data transfer can be reduced.

Furthermore, in this embodiment, if the display device dedicated bus 108 is opened and an image input device such as a scanner is connected, the image data read from the image input device can be read and stored as compressed data on the host computer side. It is possible.

Next, a fourth embodiment will be explained based on FIG. 4.

In the display device shown in FIG. 4, a dedicated bus is provided between the display memory and the compression means, and compression processing and compressed data reading are performed in a pipeline.

In the third embodiment, the compression process in step 3 and the compression process in step 4
Since the readout process uses the bus 108 within the display device, a bus collision occurs, and the readout process is performed sequentially under bus arbitration.

On the other hand, in the thick embodiment shown in FIG. 4, by providing a dedicated bus 111 between the display memory 105 and the compression means 110, the compression means 110
Display-only main control means 1 that does not require access to 08
01 is transferring the compressed data, the compression means 110
It becomes possible to perform the next compression process in parallel. In other words, parallel operation of step 3 and step 4 in the first embodiment of a43 is possible.

As described above, according to the third embodiment, compression processing and readout processing are pipelined to realize faster compression and readout processing.

By the way, in the embodiment of ml-24, if the data to be displayed is compressed image data, the computer 2 transfers it to the display device l via the system bus 205, and the display-only main control means 101 receives the received data. It will be written into the display memory 105 as is. Therefore, in this case, although the writing process to the display memory by the server on the display device 1 can be sped up, the communication load between the server and the client is not reduced.

However, in the fifth and sixth embodiments described below, it is possible to reduce the communication load even when compressed data is not used for communication data between the server and the client.

That is, the display device of the fifth and fJ46 embodiments is as follows:
The interface with the host computer is equipped with memory (shared memory) that can be accessed by both the client program and the server program.
Data communication between sites is performed using data pointer addresses in a shared memory. Currently, this configuration is such that the server and client are on the same machine. In other words, shared memory via a network interface is not currently implemented.

However, if the memory on different machines on the network can be shared, they do not need to be the same machine.The fifth embodiment will be explained below based on FIG. The display device in this embodiment transfers display data from a client on a host to a server on the display device using compressed data, and the communication is performed by copying a pointer address on a shared memory.

That is, in FIG. 5, the configuration of the host computer 2 is the same as that in the first embodiment, but as a host interface in the display device, the interface is shared between the client on the host computer 2 and the wind server on the side of 1 display device l. A shared memory 112 is provided.

Hereinafter, the display operation of compressed image data in the display bag M1 will be explained step by step.

C step l): The client on the host computer 2 saves the compressed image data to the auxiliary storage! 203 onto the shared memory 112.

C step 2): The client uses the shared memory 112
Sends the pointer address of the compressed data in the server to the server. This communication is assumed to be performed using a predefined space in the shared memory. Specifically, the main control unit 201 of the host computer 2 writes a message consisting of a display command and a pointer address of the compressed data in the shared memory into a defined space of the shared memory 112, and the display-only main control unit 101 writes the message to a space defined by the shared memory 112.・Detect that a sausage has been received.

C step 3): The display-only main control means 101 analyzes the received message and instructs the decompression means 104 to start decompression processing. In this case, assuming that the decompression means 104 has a function of reading data, the display-only main control means 10
1 passes the pointer address of the compressed data on the shared memory 112 to the decompressing means 104 at the time of startup.

(Step 4): The decompression means 104 uses the shared memory 112
The above compressed data is sequentially read and decompressed. In other words, the shared memory 112 between the server and client allows
Communication of compressed data is essentially performed by copying pointer addresses on memory.

(Step 5): The display-only main control means 101 transfers the decompressed data of the decompressing means 104 to the display memory 105 based on the window management information, paying attention to the overlapping portion.

In this embodiment, the shared memory 112 and the decompression means 104
If a dedicated bus 113 is provided between the two, it becomes possible to pipeline the decompressed display processing as described in the second embodiment.

Next, a sixth embodiment will be explained based on FIG. 6.

That is, in this embodiment, the compression means 110 compresses and reads image data from the window server on the display device 1 side to the client on the host computer 2, and the data communication between the server and the client at that time is performed using the shared memory 112. This is done by copying the above pointer address.

Hereinafter, the operation of reading compressed image data from the display memory in the display bag will be explained step by step.

(Step 1): The client on the host computer 2 sends an instruction to read data in the display memory 105 to the server.

[Step 2): The display-only main control means 101 analyzes the received message and stores it in the display memory 1 in the compression means 110.
Commands to start compressed reading of data on 05.

In this case, it is assumed that the compression means 110 can read data from any area in the display memory 105. therefore,
At startup, the display-only main control means 101 instructs the coordinate address of the readout area.

(Step 3): The compression means 110 reads out the designated area data on the display memory 105 and performs compression processing.

[Step 4]: The display-only main control means 101 reads the compressed data from the compression means 110 and writes it into the shared memory 112.

(Step 5): The display-only main control means 101 uses the shared memory 112 as compressed data to be sent back to the client.
Write the pointer address of the above compressed data and send.

In this embodiment, display memory 105 and compression means 110
If a dedicated bus 111 is provided between the two, it becomes possible to pipeline the compressed read processing as described in the fourth embodiment.

In this manner, according to the fifth and sixth embodiments, data communication between the server and the client can be performed using pointer addresses on the shared memory 112, and the communication load can be reduced to the maximum. In other words, the amount of communication data can always be set to the pointer size, regardless of the size of the image data (including compressed data).

Furthermore, even if the communication data between the server and the client is not compressed data, the amount of communication data is equal to the pointer size r(), so the communication load can be reduced regardless of whether the data is compressed or uncompressed.

As described in detail, according to the configuration of the great invention, high-speed transfer of bitmap data independent of a host computer,
It becomes possible to reduce the communication load between the server and the client, and it becomes possible to use a general-purpose workstation as a base system for application development using both natural images and CG images.

Furthermore, since natural image transfer via a network can be performed at a higher speed than in the past, it becomes possible to realize an image retrieval system configured using an image database device and a search terminal using a network.

[Brief explanation of drawings]

1 to 6 are block diagrams showing the configuration of workstations in the first to sixth embodiments of the great invention, respectively, FIG. 7 is a block diagram showing the configuration of a conventional workstation, and FIG. The figure is a conceptual diagram of image display processing in a server/client type window system. 1...Display device, 2...Host computer, 10
1... Display-only main control means, 102... Host interface, 103...-Work memory, 104...
Decompression means, 105...Display memory, 106--Continuation control means, 107--D/A converter, 108--Display device internal bus, 109--Work memory/decompression means dedicated bus, 110... Compression means, 111... Bus dedicated to display memory compression means, 112... Shared memory, 113... Bus dedicated to shared memory expansion means. Agent Yoshihiro Moriki Figure 1 *Nitoko/Vita/Display device/Figure 2 Computer/Display! ! Installation --- / Figure 3 Figure 4 / Host computer display device / Figure S Host computer 7- - Display device / Figure 4 Host combicoater / ! lR'449. -7

Claims (1)

[Scope of Claims] 1. A display device for a computer, which includes a main control means for controlling the entire device via a dedicated bus, a host interface for communicating with the computer, and a workpiece used by the main control means. a memory, a decompression means for decompressing compressed bitmap data from the computer, a data display memory, a readout control means for reading out the data in the display memory in synchronization with a display screen, and a readout control means for reading out the data from the display memory. a D/A converter that converts digital data into analog signals; (hereinafter referred to as a server), and the display device operates this server on the display device. 2. A dedicated bus is provided between the work memory and the decompression means, and the decompression means performs decompression processing by reading data on the work memory, and the main control means reads the decompressed data from the decompression means. 2. The display device according to claim 1, wherein the display device is configured in a pipeline. 3. The apparatus according to claim 1, further comprising a bitmap data compression means in the apparatus, and bitmap data communication from the server to the client is performed using compressed data in response to a request from the client to read data from the display memory. Display device as described. 4. A dedicated bus is provided between the display memory and the compression means, and the compression means performs a compression process by reading data on the display memory, and the main control means reads out the compressed data from the compression means. 4. The display device according to claim 3, wherein: 5. A shared memory that can be accessed by both the server and the client is used as the host interface, and data communication between the server and the client is performed using a pointer address of data on the shared memory. 4. The display device according to any one of 4.