JPH0542517Y2 - - Google Patents

Description

[Detailed description of the invention] <Industrial application field> This invention relates to a graphic display device, and more specifically, it performs visual display based on graphic data transferred from a host processor via a parallel interface via DMA. The present invention relates to a graphic display device.

<Prior art and problems to be solved by the invention> Conventionally, graphics data supplied from a host processor is input, and coordinate conversion processing, clipping processing, coloring processing, etc. are sequentially performed on the display device. Visually graphical display devices are provided.
Graphic display devices are required to display as fast a display speed as possible. The operating system (hereinafter referred to as OS) in the upper processor
The parallel interface, which can directly perform DMA transfer between memories without the need for a DMA transfer (abbreviated as ``)'', allows for high-speed transfer.

Therefore, when it is necessary to edit, compile, or execute a program in the upper processor, it becomes impossible to transfer data from the graphic display device to the upper processor through the parallel interface. In practice, as shown in FIG. 5, a character terminal device 32 is provided separately from the graphic display device 31, and a serial interface 34 is used to connect the character terminal device 32 and a host processor 33. ing.

By adopting this configuration, necessary data can be transferred from the character terminal device 32 to the upper processor 33 through the serial interface 34, and by supplying the necessary data, the upper processor 33 can transfer the OS. Edit, compile, and edit programs under your control.
A series of processes for execution etc. can be performed. Furthermore, by transferring the necessary data to the host processor 33 through the serial interface 34, the parallel interface 35 is activated, so that DMA transfer by the parallel interface 35 will be performed from now on.
The upper processor 33 can perform other processing in parallel with DMA transfer.

However, in the graphics system with the above configuration, graphics data is sent to the upper processor 33 via the parallel interface 35.
There is a problem in that it is necessary to connect the display device 31 and also to connect the character terminal device 32 via the serial interface 34, resulting in a complicated configuration.
To explain in more detail, the graphics system with the highest operating rate is the graphics system.
a display device 31, and a parallel interface 35, a character terminal device 32,
The serial interface 34 is only required for editing, compiling, and executing programs, or for activating the parallel interface 35, and its operating rate is not very high. Even in such a situation, since the character terminal device 32 is required to perform DMA transfer through the parallel interface 35, the character terminal device 32 is required, although it complicates the configuration and increases costs. This results in the user having to wear a terminal device.

<Purpose of the invention> This invention was made in view of the above problems, and the object is to provide a graphics display device that can simplify the configuration of a graphics system by omitting the character terminal device. The purpose is

<Means for Solving the Problems> To achieve the above object, the graphic display device of this invention has a serial interface with a console function, and
It has an input/output port that supports a parallel interface that supports DMA transfer, and can also send and receive data only through the serial interface, and can also send and receive data through the parallel interface and from the upper processor through the serial interface. It has a selection control means for selecting a data receivable state.

However, it is preferable that the input/output port corresponding to the serial interface has data conversion means for converting between serial data and parallel data.

Further, it is preferable that the input/output port corresponding to the parallel interface has a transmitting/receiving buffer.

Furthermore, the selection control means is set as an initial state to allow data exchange only through the serial interface, and
Preferably, when a switching command is supplied through either interface, the other state is selected.

<Function> The graphic display device with the above configuration has input/output ports compatible with a serial interface with a console function and a parallel interface that supports DMA transfer, and it also has input/output ports that support a serial interface with console function and a parallel interface that supports DMA transfer. The selection control means selects a state in which data can be exchanged from the host processor, a state in which data can be transmitted and received through the parallel interface, and a state in which data can be received from the upper processor through the serial interface. By selecting a state in which data can be exchanged only through the interface, and in this state, the graphic display device supplies data for starting the parallel interface to the upper processor.
A state can be established in which DMA transfers over the parallel interface can occur.

When a state in which DMA transfer is possible is established, the selection control means selects a state in which data can be exchanged through the parallel interface and data can be received from the higher-level processor through the serial interface. By DMA-transferring graphical data from the computer through a parallel interface, visual display can be performed on a graphic display device.

Hereinafter, any one of the above operations can be performed each time a new selection operation is performed by the selection control means.

If the input/output port corresponding to the serial interface has data conversion means for converting between serial data and parallel data, data transfer within the graphic display device is performed in parallel. The time required for data transfer can be shortened.

Further, if the input/output port corresponding to the parallel interface has a transmitting/receiving buffer, data processing by the graphic display device can be performed efficiently regardless of the DMA transfer speed.

Further, the selection control means is set as an initial state to a state in which data can be exchanged only through the serial interface, and when a switching command is supplied through either interface, selects the other state. In this case, when the graphics system is initially started up, a state in which data can be exchanged only through the serial interface is selected, so it is possible to execute programs, etc., and it is also possible to use the parallel interface. It is possible to establish a state in which it can be activated and perform DMA transfer. Therefore, if a switching command is supplied in this state, the selection control means will
DMA through parallel interface, since different states can be selected.
Transfer is performed and graphics can be displayed at high speed. Furthermore, since the state is switched every time a switching command is supplied after that, the state in which the program is edited, compiled, executed, etc.
It is also possible to easily select the state in which graphic data is transferred at high speed by DMA transfer.

<Examples> Hereinafter, examples will be described in detail with reference to the accompanying drawings showing examples.

FIG. 4 is a schematic diagram showing the configuration of a graphics system incorporating the graphics display device of the present invention.
A memory (not shown), a serial interface 13, and a parallel interface 14 are connected to the data bus 12 (abbreviated as ) 11.
1, and a graphic display device 2 having input/output ports 21, 22 connected to both the above-mentioned interfaces 13, 14.

FIG. 3 is a schematic diagram showing the detailed configuration of the graphic display device 2, in which a serial-to-parallel converter (hereinafter abbreviated as S/P converter) 2
1a, a parallel interface control section 22a, an input/output port 22 having a transmission/reception buffer 22b for parallel data, a switching control processor 23, and a random access memory (hereinafter abbreviated as RAM). a transmission/reception buffer 24 for the program, a memory 25 for the program consisting of RAM, the input/output ports 21 and 22, and a switching control processor 2.
3, a transmission/reception buffer 24, a memory 25, and a data bus 26 for transferring data between other processors (not shown).

Therefore, when the input/output port 21 is selected by the switching control processor 23, data transferred from another processor (not shown) is temporarily stored in the transmission/reception buffer 24, and data read from the transmission/reception buffer 24 is stored. By supplying the data to the S/P converter 21a, it is possible to convert it into serial data and supply it to the host computer 1. In the host computer 1, the above data can be taken into the CPU 11 through the serial interface 13 and the data bus 12. Therefore, by transferring predetermined data from the graphic display device 2, it is possible to edit, compile, execute, etc. a program in the host computer 1, and also to enable the parallel interface 14 which performs DMA transfer of data. It can be activated.

In addition, when the input/output port 22 is selected by the switching control processor 23, the parallel interface 14 has already been activated, so the parallel data sent from the host computer 1 is supplied to the transmission/reception buffer 22b. be able to. And the transmitting/receiving buffer 22
The data read from B can be supplied to other processors through data bus 26 to perform processing necessary for graphic display.

FIG. 2 is a flowchart illustrating the operation of the graphic display device in detail, including a console mode in which data is exchanged only through the serial interface 13, a console mode in which data is exchanged through the parallel interface 14, and a data exchange through the serial interface 13. It is roughly divided into the graphic mode that receives the supply.

() Console mode This mode determines whether it is necessary to change the mode in a step, that is, whether a mode change command is received through the parallel interface 14 and the input/output port 22, and executes the mode change. If it is determined that it is necessary to do so, the series of processing in the graphics mode is directly executed. On the other hand, if it is determined that there is no need to change the mode, the data communication subroutine A is executed in step to take in serial reception data through the serial interface 13 and input/output port 21, and the received data is processed in step. Determine whether data exists. If it is determined that there is received data, the received data processing subroutine is executed in step.
Predetermined data is obtained, and in a step it is determined whether or not there is data to be transmitted. Conversely, if it is determined in the above step that there is no received data, the process in the step is omitted and the determination in the step is performed directly.

If it is determined in the above step that transmission data exists, the transmission data processing subroutine is executed in step
Data conforming to the transmission format is generated, and it is determined in step whether or not data transmission should be performed. On the other hand, if it is determined in the above step that there is no transmission data, the process of the step is omitted and the determination of the step is performed directly.

If it is determined in the above step that data transmission should be performed, data communication subroutine B is executed in step to generate serial transmission data, and the data is transferred from the input/output port 21 through the serial interface 13. After that, the next serial data can be sent and received by repeating the series of determination processes following the steps. On the other hand, if it is determined in the above step that data transfer should not be performed, the process in the step is omitted and the next serial data is sent and received by directly performing the series of determination processes following the step. I can do it.

() Graphics mode This mode determines whether it is necessary to change the mode in a step, that is, whether or not a mode change command has been received through the parallel interface 14 and the input/output port 22, and then changes the mode. If it is determined that it is necessary to perform this, the series of processes in the console mode described above are performed as is. On the other hand, if it is determined that there is no need to change the mode, the data communication subroutine A is executed in step to take in serial reception data through the serial interface 13 and input/output port 21, and the received data is processed in step. Determine whether data exists. If it is determined that there is received data, a console display is performed based on the received data in step, and data communication subroutine C is executed in step to connect the parallel interface 14,
and takes in parallel reception data through the input/output port 22. Conversely, if it is determined in the above step that there is no received data, the processing in the step is omitted and the processing in the step is directly performed.

After performing the processing in the above steps, it is determined in step whether or not there is parallel reception data, and if it is determined that parallel reception data exists, the reception data processing subroutine is executed in step. , predetermined data is obtained based on the parallel received data, and it is determined in step whether or not there is data to be transmitted. On the other hand, if it is determined in the above step that parallel reception data does not exist, the step processing is omitted and the step determination is performed directly.

If it is determined in the above step that transmission data exists, the transmission data processing subroutine is executed in step
Data conforming to the transmission format is generated, and it is determined in step whether or not data transmission should be performed. On the other hand, if it is determined in the above step that there is no transmission data, the process of the step is omitted and the determination of the step is performed directly.

If it is determined in the above step that data transmission should be performed, data communication subroutine D is executed in step 21 to generate parallel transmission data, and the data is transferred from the input/output port 22 through the parallel interface 14. After that, by repeating the series of determination processes below the step, the next serial data can be received and the parallel data can be sent and received. On the other hand, if it is determined in the above step that data transfer should not be performed, the process of step 21 is omitted and the series of determination processes following the step are performed as is, thereby receiving the next serial data and Parallel data can be exchanged.

FIG. 1 is a diagram schematically explaining the operation of the graphic display device, and the operation of the above flowchart will be explained based on this schematic diagram.

First, when the power is turned on, the initialized console mode is selected, so serial data is exchanged with the host computer 1 through the serial interface 13, allowing interactive operation. By doing so, the program can be edited, compiled, executed, etc., and the parallel interface 14 can be activated. Therefore, graphic data can be supplied from the host computer 1 to the graphic display device 2 through the activated parallel interface 14.

Further, if a mode switching command is supplied through the parallel interface 14 after the parallel interface 14 is activated, data is exchanged through the parallel interface 14, and the serial interface 13
A graphics mode in which data reception is performed through is selected. Therefore, processing is performed based on data exchanged at high speed through the parallel interface 14, and interrupt processing is performed based on data supplied from the host computer 1 through the serial interface 13, thereby displaying system messages. can also be done at the same time.

Thereafter, when a graphics mode end command (corresponding to a mode switching command) is supplied through the parallel interface 14, the console mode in which data is exchanged with the host computer 1 through the serial interface 13 is selected again.

In other words, by simply connecting only one graphics display device 2 to the host computer 1, you can operate the console mode with OS support and the console mode without OS support.
It is possible to perform both graphics modes that perform DMA transfer, simplifying the configuration of the graphics system as a whole, and
Cost reduction can be achieved.

Note that this invention is not limited to the above-described embodiment; for example, data reception through a serial interface in the graphics mode can be performed after parallel reception data processing or after data transmission processing. In addition, data can be received through the serial interface at all of these timings, and various other design changes can be made without changing the gist of the invention.

<Effects of the invention> As described above, this invention provides a graphic display device with an input/output port corresponding to a serial interface and an input/output port corresponding to a parallel interface, and allows input/output port selection by a selection control means. This not only makes it possible to exchange graphic data at high speed through DMA transfer, but also allows for startup of a parallel interface, program editing, and compilation without the need for a character terminal device. , execution, etc., and the overall configuration can be simplified, which is a unique practical effect.

In addition, by selecting a state in which data can be exchanged through the parallel interface and data can be received from the upper processor through the serial interface, processing based on data exchanged at high speed through the parallel interface and data supplied through the serial interface can be performed. It also has the unique practical effect of being able to perform processing based on the data to be displayed almost simultaneously, and displaying based on both data at the same time.

[Brief explanation of the drawing]

FIG. 1 is a diagram schematically explaining the operation of the graphic display device of this invention, FIG. 2 is a flowchart explaining the operation of the graphic display device in detail, and FIG.
FIG. 4 is a schematic block diagram showing the configuration of an embodiment of a display device, FIG. 4 is a schematic diagram showing a graphics system using the graphics display device of this invention, and FIG. 5 is a schematic diagram showing a conventional graphics system. 1... Host computer, 2... Graphic display device, 13... Serial interface, 14... Parallel interface, 21, 22... Input/output port, 21a...
S/P converter, 22b...transmission/reception buffer, 23
...Switching control processor.

Claims (1)

[Claims for Utility Model Registration] 1. A graphics display device that provides visual display based on graphic data transferred from a host processor via a parallel interface via a DMA transfer, which supports a serial interface with a console function and DMA transfer. It has an input/output port that supports a parallel interface, and can send and receive data only through the serial interface, and can send and receive data through the parallel interface and receive data from the host processor through the serial interface. 1. A graphic display device comprising selection control means for selecting. 2. The graphic display device according to claim 1, wherein the input/output port corresponding to the serial interface has data conversion means for converting between serial data and parallel data. 3. The graphic display device according to claim 1, wherein the input/output port corresponding to the parallel interface has a transmitting/receiving buffer. 4. The utility model described above, wherein the selection control means is set as an initial state to a state in which data can be exchanged only through a serial interface, and when a switching command is supplied through either interface, selects the other state. Graphics as stated in Paragraph 1 of the Registered Claims
Display device.