JPS59219784A - Display controller for large virtual screen - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Technical Field to which the Invention Pertains] The present invention relates to a display device that performs two-dimensional display, such as a cathode ray tube (hereinafter referred to as CRT) or a dilasma display panel, and a display range that can be displayed at one time by the device. A large virtual machine that can take out any part of the display contents stored in a storage area larger than that of a computer's random access memory (hereinafter referred to as RAM) and display it in the form of a continuous screen. The present invention relates to a screen display control device.

[Prior art and its problems]

In the display control device to which the present invention is directed, the screen is originally horizontally elongated, for example, the panel surface of an extremely wide control panel and the panel surface mounting are used as a screen for arranging instruments, but as the screen becomes long, the display device Since I can only display part of it,
Manually or automatically move the partial display screen to another part of the original screen by key operation or a computer program,
Alternatively, a large virtual screen is handled in which it is necessary to selectively display any required portion of a screen that is originally vertically long. The display content to be displayed on the screen of such a display device is stored in an area set in a storage device in a computer or in a so-called refresh memory provided separately from a normal storage device, and forms a so-called virtual screen with a storage area corresponding to the entire screen that can be displayed by the display device. Note that the display contents or data stored in the storage area forming this virtual screen may be stored in the central processing unit of the computer, for example, as necessary.
(hereinafter referred to as CPU) is not changed or refreshed.

An example of conventional display control means for such a large virtual screen is shown in FIG. A refresh memory 2 is provided corresponding to a display range 1 that can be displayed at one time on a two-dimensional display device such as a CRT, and the two have a one-to-one correspondence in terms of display data. On the other hand, the large virtual screen 3 is shown as an area surrounded by a dashed line in the figure, and since it is naturally impossible to store all the display data of this large virtual screen in the refresh memory 2 mentioned above, the large virtual screen 3 The display data is stored in another mass storage device, such as the disk memory 4 shown in the figure. When you want to move the display range l within the large virtual screen, operate the movement command device 5, for example, the movement command keys for up, down, left and right movement, and the specified movement command is sent to C! P.U.
6 receives the command, software pre-programmed therein is activated, and commands necessary for moving the display range are output to the command register. Based on this command, the command register 7 reads display data necessary for moving the display range from the disk memory 4, rewrites the display data in the refresh memory 2 with new display data, and displays this new display data in the display range 1. be done.

With such conventional control means, a command to move the display range is issued. Start the software in PU6,
Operates command register 7 and stores disk memory 4
Since it is necessary to transfer the display data from the display area to the refresh memory 2, and this operation must be performed at each step while the display range is being moved, the response to the movement command is inevitably slow, and the display data transfer is slow. It was impossible to avoid the increase in the number of times and the loss of efficiency.

In addition to the above problems, when one CPU attempts to control a plurality of display devices, it becomes increasingly important to increase the response speed to movement commands and increase the display data transfer efficiency. With the spread of CRT devices in recent years, the number of cases in which multiple display devices need to be controlled continues to increase.
With the conventional means as described above, a decrease in processing speed and an increase in the amount of data transfer cannot be avoided.

[Purpose of the invention]

In view of the above circumstances, the present invention provides C! A large virtual screen display control device that can move the display range within a large virtual screen by issuing minimal control data from the PU, has a fast response speed to display range movement commands, and has high display data transfer efficiency. Our goal is to provide the following.

[Key points of the invention]

As a means for achieving the above-mentioned object, the present invention first stores the display data of the large virtual double-sided display in a display content storage device provided for each display device in order to reduce the amount of display data transferred. The refresh memory is composed of two refresh memories, and all display data is divided and stored among these refresh memories. As such a refresh memory, in recent years, RAMs have significantly increased in capacity and decreased in price, and this can be effectively utilized, and the time required to read transferred data from a disk memory device is not required. Next, a display range designation device for reading data of a display range to be outputted to a display device from the storage device is provided for each storage device, and a reference address of the display range to be read is sent to the display range designation device in a refresh memory. A scroll register for storing data for each refresh memory and a mask register for controlling which refresh memory should output display data are provided. As the above reference address, a reference address in two directions, x and y, is specified corresponding to the two-dimensional display, and this reference address is qualified with a scan address in the display screen and specified in synchronization with the scanning of the display device. The display data within the display range is sequentially read from the refresh memory and displayed. A mask register designates this particular refresh memory, and stores mask data that designates from which memories reading of display data is prohibited and from which memories reading is permitted. Therefore, the display range specifying device only needs to receive this mask data and a movement command that specifies the direction and amount of movement of the screen, and can move within the specified display range without placing any additional burden on the higher-level device. Display data can be read from the display content storage device described above and output to the display device.

A display range control device is provided to provide the reference address and mask data of the display range to the above-mentioned display range designation device. Although this control device is small, it constitutes one processing unit, and is equipped with so-called firmware in its attached memory.The firmware performs most of the display control functions, and minimal control is required from the CPU. All you have to do is give commands or data. The display range control device configured as the processing unit receives the command to move the display range, outputs a reference address change signal to change the reference address in the scroll register of the display range designation device, and moves the display range;
The limit reference address of the display range that can be output from the memory is always stored for each refresh memory, and when the reference address change signal must specify a reference address exceeding the limit value, the display range specifying device is masked. The data is rewritten and the refresh memory that outputs the display data is switched. Note that the display range movement command may be given from the CPU to the display range control device, or the display range control device may directly receive a movement command from a movement command device placed at the site where the display device is located, without going through the CPU. You can do it like this.

However, it is also possible to control a plurality of display range specifying devices and therefore a plurality of display devices using one display range control device.

With the above configuration of the device of the present invention, C
The PU only needs to give the minimum control commands and data to the display range control device, and many display devices can be controlled by one CPU.
In addition, the display range specifying device can move the display range to a specified position on the large virtual screen simply by receiving the reference address change signal and mask switching signal from the display range control device. The time from when a movement command is given until the display range is moved is shortened, and there is no need to transfer a large amount of display data.

[Embodiments of the invention]

FIG. 2 shows the basic configuration of a large virtual screen display control device according to the present invention, and the same parts as in FIG. 1 are given the same reference numerals. In the figure, reference numeral 10 denotes a display device, which includes a scan address generator 11 that emits a scan address signal synchronized with the rask scan necessary for display, and a video signal generator that converts display data expressed as digital values into a video signal. a video controller 13 and a video controller 1
and a CRT device 14 which receives the video output signal from the video signal generator 12 of No. 3 and displays it on a CRT screen. A display content storage device stores display data to be displayed on the display device 10, and in this embodiment, it consists of two refresh memories 21 and 22.

The range that can be displayed on the CRT device 14 at one time is indicated as a display range l, and all display data of the large virtual screen 3 described above is stored in these two refresh memories 21 and 22. The display range specifying device 30 specifies the display range l to be displayed on the CRT device 14 from all the display data, and in this example, scroll registers 311 and 312 and a mask register 321 provided for each refresh memory are used. , 322.

Now, since the display on the CRT device 14 is a two-dimensional display,
Display data within display range 1 has two addresses in both the X and Y coordinate directions. Therefore, the reference address specified for scroll register 311 or 312 or refresh memory 21 or 22, respectively, is also two coordinate addresses X and Y.
In the figure, the reference addresses X and Y are specified by the scroll register 311, and in this example, the positions corresponding to the specified reference addresses X and Y are within the display range in the refresh memory 21. It is shown as reference address point 1a in the upper left corner. The display range specifying device 30 is connected to the aforementioned scan address generator 11 via the address bus 41 of the data bus 40 as shown in the figure, and receives the scan address signal generated by the scan address generator 11 (7). Then, it is added to the reference addresses X and Y in synchronization with the mask scan of the CRT device 14, and the display data within the display range 1 of the refresh memory 21 is sequentially read out and sent to the display data bus 42 of the data bus 40 as described above. to the video signal generator 12 of C.
It is displayed on the screen of the RT device 14.

On the other hand, the mask registers 321 and 322 of the display range specifying device 30 have a logical value such as "0" that prohibits reading of display data from the refresh memories 21 and 22, respectively, or a logical value that allows reading of display data as mask data. In the illustrated case, the mask register 321 stores the logical value rlJ, allowing readout of display data from the refresh memory 21, and the mask register 322 stores the logical value “ 0" is stored in the refresh memory 22.
Reading from is prohibited.

The command to move the display range within the large virtual screen is issued by the illustrated movement command device 50 or C! Given to PU6. The movement command device 50 includes, for example, four keys for selectively instructing screen movement in up, down, left, and right directions as shown in the figure, and the direction in which the display range 1 is moved by these keys is indicated by an arrow. . The movement command issued by the CPU 6 does not simply command the screen to move vertically and horizontally, but may also command the reference address to which the display range 1 should be moved all at once. in any case,
This movement command is given to the processing unit 61 (hereinafter referred to as PU) of the display range control device 60, and the POC3
Based on this, the display control software preprogrammed in the attached firmware 62 is activated, and a control command is given to the display range specifying device 30 via the data bus 40 (address bus 41 in the illustrated example).

Note that 61a in the figure is the PU 61 for the movement command device 50.
is the input boat.

Now, the large virtual screen 3 is, for example, a horizontally long screen as shown in FIG.
Refresh memo IJ of the same size 21
, 22 are conveniently divided into five parts of the same size, denoted by A to E.
Each part is stored in the refresh memories 21 and 22 in the arrangement shown in (a). In other words, the same figure (1)
The same display data as part B of the same figure (b) is stored redundantly in the parts indicated by Bl and B2 of the same figure (a).
The same display data as parts C and D in FIG. 2B are stored in parts 01 and 02 and DI and B2, respectively. Take both the x and y coordinates in the direction shown by the arrow in FIG. 3(a), and set the coordinates of the upper left corner of the refresh memory 210 portion A as Xi, Yl, and similarly, the coordinates of the upper left corner of portion C1 as X2, Y2, and these coordinates X1. ,
X2.

The values of Yl and Y2 are stored in the memory area of the firmware 62 as shown in FIG.

Furthermore, as shown in FIG. 1, the display range l is in part A of the refresh memory 21, and the reference addresses X and Y at the upper left corner are similarly stored in the variable memory area of the firmware 62, and the display range 1 to the right is given by the movement command device 50, the display range control device 60 receives this movement command and changes the address X in the X direction of the reference addresses X and Y to X −4-1
At the same time, the reference address X in the scroll register 311 of the display range specifying device 30 is replaced with the same value, and the display range 1 is moved to the right by one address.
Thereafter, the display range is sequentially moved to the right in the same manner.

Assuming that the display range l enters into part B1 of the refresh memory 21 due to such movement to the right, and the coordinates of the right end of the display range reach the coordinates of the right end of part B1, the display range 1 becomes part of the part B1. ! Since it is not possible to move further to the right until then, the display range 1 is switched all at once to part B2, which stores the same display data as part B1. The need for such switching is based on the value of X in the variable memory area of the firmware 62 and the pre-stored values XI, X2
It can be found by comparing the value of
When it becomes X2, switching is necessary. Also, as a switching operation, if the value of X is replaced with Xl and the value of Y is replaced with Y2, display range 1 moves from part Bl to B2,
Thereafter, the process further advances to part C1.

When the right end of display range 1 matches the right end of portion C1, under the above assumption, such a match is detected under the conditions that X = X2 and Y = Y2, and display range 1 is Refresh memory 22
is switched to part C2. This switching operation not only replaces the value of At the same time, the value stored in the mask register 322 is replaced with "1" from the refresh memory 21, and the value stored in the mask register 322 is replaced with "1" from the refresh memory 21. Reading of display data from 22 is permitted.

By this operation, the display range l is changed to the refresh memory 21.
Then, the display moves to the refresh memo 1722, and thereafter, the movement of the display range 1 to the right continues in the same manner until it reaches the portion E. In the above, to simplify the explanation, the size of display range 1 was made to be the same size as each part A to E of the refresh memory for convenience, but in the general case where the size of the display range is smaller than the size of each of these parts. The principle is the same as described above, except that the conditional expression for detecting the necessity of the switching operation and the method of substitution during the switching operation are slightly different. For example, the condition for detecting the need to switch the display range 1 from part 01 of the refresh memory 21 to part C2 of the refresh memory wing is x = 2X2- xx - BX
(However, BX is the width of the display range l in the X direction) and Y>
Y2, and the replacement operation is to change the value of X to
+ Xi, the value of Y may be replaced by Y - Y2 + Yl. Also, in the case where the large virtual screen is different from the horizontally elongated screen in Fig. 3(b), it is a vertically elongated screen as shown in Fig. 3(c) in which parts A to E are arranged vertically downward. , when moving the display range l downward, contrary to the horizontal case, from part B2 to B1, and from part D2 to Dl.
Other than the switching to 02, the operation of switching from part C1 to 02 and other implementations are the same as in the case of the horizontally long large virtual screen.

As explained above, the display range control device 60 has a pH of 10
The firmware 62 includes reference addresses X and Y as variables indicating the current position of the display range, and coordinate addresses XI necessary for switching between the refresh memories 21 and 22.

X2, Yl, and Y2 are stored in advance, and the PH10 constantly checks the necessity of switching the refresh memory according to the software preprogrammed in the firmware 62, and when switching is necessary, performs the above-mentioned procedure. At the same time as switching the plane number PLNO of the refresh memory, the display range specifying device 3
0 in the mask registers 321 and 322, and the values of the variables x and Y, that is, the reference addresses in the scroll registers 311 and 312 of the display range specifying device, in a predetermined manner necessary for switching the refresh memory. replace.

-) 5, apu6id! J Fresh Memory 21, 2
In addition to performing the initial writing of display data to the PH 2 via the PH 10 of the display range control device 60 and the display data bus 42, it is also necessary for loading software into the attached firmware 62 of the PH 10 and switching the refresh memory. However, after the loading and writing are completed, the display range control device 60 is responsible for the subsequent operations as much as possible. However, C
The PU itself also sends commands to move the display range to the display range control device 60.
A MODE column is provided in the memory area of the firmware as shown in FIG. The operating mode is specified.

The operation modes of this PU 61 include the above-mentioned writing mode of display data to the refresh memory, mode of changing the display data, loading mode and writing mode to the attached firmware 62, and the mode of writing the display data to the refresh memory, as well as the mode of loading and writing the attached firmware 62.
There are a display range movement command mode from 6 and a display range movement command mode from movement command device 50, and software specified by the mode in firmware 62 is activated according to each mode.

Therefore, when a movement command is issued from the movement command device 50, the PU 61 receives this movement command and sends a message to that effect (!PU
6, and if there is no conflict with the movement command from itself, the CPU 6 issues manual operation permission from the movement command device 50 to the PU 61 in the form of a manual operation command, and sets the MODE field in the aforementioned armware 7 for manual operation. mode.

However, it is not necessarily a good idea to store all the software for all modes performed by the PU 61 in the attached firmware 62, and the software necessary for writing display data to the refresh memory and the display data management mode mentioned above is rather It is often advantageous to have one on the 0PUS side in order to manage a large number of display ranges with one CjPU.

In this case, in this operating mode, the PU 61 receives commands in the software from the 0PU 6 and controls the data bus 50 and the like based on the commands. Note that even in the manual operation mode using the movement command device 50, it is often more advantageous to command operations such as refreshing memory switching from the 0PU6 side in order to manage a large number of display ranges, and in such cases, the PU61 A report to the effect that switching is necessary due to movement of the display range according to a movement command is sent to the 0PU6 as interrupt information. This interrupt information includes, for example, the current movement direction and the reference address values X and Y of the current display range, and when the 0PU6 decodes this interrupt information and determines that it is okay to continue the movement command, In addition to issuing the manual operation mode command again, if necessary, the plane number P of the refresh memory is
The aforementioned limit reference address values XI, Yl or X2, Y2 as limit values for LNO and next screen movement are specified to the display range control device 60. CPU required
The administrative intervention by 6 can be carried out if necessary by mutual switching between parts in the refresh memory mentioned above, e.g.
Exactly the same operation can be performed when switching the display range l between Dl and B2 or between Dl and B2.

In the above detailed description of the present invention, the case where there are two refresh memories has been described, but the present invention is applicable to all cases where the number of refresh memories is not limited to two but is generally plural. Of course, it can be implemented. Furthermore, for the sake of simplicity, we have explained an example in which the scroll register of the display range specifying device is provided for each refresh memory, but the method of dividing the aforementioned portions A to E in the refresh memory is the same across multiple refresh memories. If there is, it is possible to make do with one scroll register. It is of course not necessary to provide a mask register for each refresh memory; for example, it is sufficient to provide one ring counter for multiple refresh memories to specify whether reading of display data is prohibited or permitted. It is possible.

〔Effect of the invention〕

As explained above, in the large virtual screen display control device according to the present invention, a display content storage device consisting of a plurality of refresh memories for storing all display data of the large virtual screen is provided for each display device, and a display range is specified. Using the device's scroll register and mask register, it is now possible to easily specify and change which part of the refresh memory the display data is read from and displayed on the display device. There is no need to transfer data, and there is no need to start up software at each step during the display range movement operation, so the display range can be moved quickly. This display range specifying device is still equipped with a display range control device that provides a reference address to which the display range is to be moved and mask data that specifies from which refresh memory the display data is to be output. Since the display range controller is responsible for most of the movement control tasks, the display range can be easily moved within the large virtual screen by issuing a minimum number of control commands or data from the CPU. , the load on the CPU is significantly reduced, and it becomes possible to control or manage a large number of display devices with one CPU.

Alternatively, since the CPU can focus on only important key points that it really needs to control or manage, it has the effect of making it possible to improve the level of management of the display of the entire system.

[Brief explanation of the drawing]

FIG. 1 is a block circuit diagram showing a configuration example of a conventional large virtual screen display control device, and FIG. 2 and subsequent figures are detailed explanatory diagrams of the present invention. FIG. 3 is a block circuit diagram showing the configuration of the display control device, and FIG.
The figure shows the allocation of main display control variables and constants in the memory area of the firmware 62 in the display range control device 60 of FIG. In the figure, l...Display range, 1a...Reference address point of display range l, 3...Large virtual screen, 5.50...Display range movement command device, 6...CPU, 10... ...Display device, 2
0...Display content storage device, 21, 22...Refresh memory, 30...Display range designation device, 311,
312...Scroll register, 32.1, 322
. . . Mask register, 60 . . . Display range control device.

Claims (1)

[Claims] 1) A display content storage device including a plurality of refresh memories that share and store display data on a large virtual screen that exceeds the range that can be displayed on one screen of a two-dimensional display device, and display data from within the storage area of the refresh memory. A scroll register that stores a reference address of a display range in which display data should be output to the device for each refresh memory, and a mask register that stores mask data that prohibits output of display data to the display device for each refresh memory,
a display range specifying device that controls display data in a predetermined display range from a predetermined refresh memory to be output to a display device based on the stored contents in both registers; and a display range specifying device that receives a command to move the display range. outputs a reference address change signal to the display range specifying device to change the reference address stored in the scroll register based on the reference address of the display range that can be retrieved from the display data stored in the refresh memory; A limit value is stored for each refresh memory, and when the reference address change signal commands a reference address that exceeds the limit value, a mask switching signal for switching the mask data stored in the mask register is specified in the display range. A display control device for a large virtual screen, comprising a display range control device for outputting to the device.