JPH05341943A - Data processor with multiwindow function - Google Patents

Abstract

PURPOSE:To reduce the burden of a CPU and to accelerate display speed. CONSTITUTION:When newly opening a second window in a state with a first window opened, the CPU 12 informs the transfer destination and the coordinates of the starting points and the terminating points of the first and the second windows to a data transfer device 11. The data transfer device 11 responds to the instruction of the CPU 12, discriminates whether or not the first and the second windows overlap, finds an overlapping area when overlapping is discriminated, saves the data in the overlapping area inside a display memory 13 to a saving destination and informs the completion of the saving of the CPU 12. The CPU 12 responds to the saving completion information and starts the control for opening the second window.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a data transfer device having a function of transferring data in a rectangular area in a display memory and a data processing system equipped with the data transfer device, which is used, for example, for controlling multi-window. It is a thing.

[0002]

2. Description of the Related Art A display control device, which is the core of a man-machine interface, may be required to have a function such as multi-window display. The multi-window display can be realized by the CPU drawing data in a rectangular area in the memory, but in order to enable high-speed display, BI
A data transfer device called T-BLT (Bit Block Transfer) is often used. BIT-BLT is a CPU
The display memory (BM
Operations such as writing data in the rectangular area M) and moving the rectangular data block in the BMM to an arbitrary position are performed.

When an attempt is made to open another window on an already existing window, it is necessary to overwrite the stored data on the BMM with another data. Here, unless the data in the overlapping portion of the windows is saved before the data is overwritten, the display screen cannot be restored when the window opened later is closed. For this reason, it is necessary to save the data of the overlapping portion of the windows in the empty area of the BMM or the empty area of the main memory.

[0004]

Conventionally, the CPU manages screen data including determination of overlapping areas of a plurality of windows and saving of data. However, the processing load of the CPU that monitors the overlapping of windows is heavy, which is one of the causes of slowing down the entire display processing. The present invention has been made to solve the conventional problems, and an object thereof is to reduce the load on the CPU and improve the display speed.

[0005]

In order to achieve the above object, a data processing apparatus according to the present invention is

It is possible to draw a second window while the first window is drawn in the display memory, which is addressable by coordinates and stores bitmap data defining a display image. A central processing unit that gives an instruction, and a determination that is connected to the central processing unit and the display memory and that determines whether or not the first window and the second window overlap in response to an instruction from the central apparatus. Means for detecting the coordinates of the overlapping area when it is determined that the first and second windows overlap, and the overlapping means before drawing the second window in response to the detection result of the detecting means. It is composed of a saving means for saving the data in the area and a data transfer device including a notifying means for notifying the central processing unit of the completion of the saving.

Further, the data transfer apparatus according to the present invention determines whether or not a plurality of rectangular areas defined on the memory overlap each other, and if they overlap each other, a detecting means for obtaining an overlapping portion, the memory and the detecting means. A transfer unit for transferring the data of the overlapping portion of the memory according to the detection result of the detecting unit, for identifying the overlapping portion of a plurality of rectangular areas on the memory, and transferring the data of the overlapping portion. Equipped with.

Further, the multi-window system according to the present invention is connected to a display memory for storing data defining a display image, the display memory, display means for displaying the display data, and the display memory. A transfer means for transferring the display data, and a second means for connecting the data transfer means to the data transfer means when the second window is further opened while the first window is opened on the display means. Control means for notifying the start and end points of the first and second windows and the transfer destination,

In response to an instruction from the control means, the transfer means determines whether or not the first window and the second window are overlapped, and if they are overlapped with each other, an overlap area is obtained, and the display memory is displayed. The data in the overlapping area is saved to the save destination, the save means is notified to the control means, and the control means performs control for opening the second window in response to the save completion notification.

[0010]

According to the data processing device and the multi-window system having the above-mentioned configuration, when a plurality of windows are opened,
The data transfer device or the transfer means itself discriminates the occurrence of overlapping windows and the address of the overlapping area, and saves the data in the overlapping area. Therefore, the burden on the central processing unit and the control means becomes lighter than in the conventional case.

Further, according to the data transfer device having the above structure, the data transfer device determines whether or not the rectangular areas defined in the memory overlap, and the address of the overlapping area. Therefore, controlling this data transfer device, for example, a CPU
Burden is reduced.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A data processing device according to an embodiment of the present invention will be described in detail below with reference to the drawings.

The data processing apparatus according to this embodiment is shown in FIG.
, The data transfer device 11, the CPU 12,
Bitmap memory (BMM) 13, main memory 1
4 and the display unit 15.

The CPU 12 operates according to a program stored in the main memory 14 and controls the operation of the entire system. The BMM 13 is a display memory and stores a display image on the display unit 15. The main memory 14 is a system memory and holds programs, data, etc. necessary for the operation of the CPU 12. Further, in this embodiment, the main memory 14 also serves as a save destination for the data of the BMM 13. Display 1
Reference numeral 5 includes a CRT, a liquid crystal display device and the like and a display controller, and displays an image defined by the bitmap data on the BMM 13.

According to the instruction of the CPU 12, the data transfer device 11 itself finds an overlapping area of an already opened window and a window to be newly opened, and obtains the data of the portion from the BMM 13 to the main memory 14 (or BM).
It is a device for transferring to a free area of M13).

The configuration of the data transfer device 11 will be specifically described below. The data transfer device 11 includes a register 1
a, 1b, 4, selectors 2a, 2b, 6a to 6d, subtractor 3, control circuit 5, bit block transfer device (Bit Bloc)
k Transfer, (hereinafter, BIT-BLT) 7 is provided.

The register group 1a has coordinates of a start point and an end point (corner coordinates, X1s, Y1) of an already opened window.
s, X1e, Y1e) is held. The register group 1b is the corner coordinates (X2s, Y2s,
X2e, Y2e) is held.

The data held in the register groups 1a and 1b are selectors 2 for selecting the X and Y coordinates for size comparison.
a, 2b. The outputs of the selectors 2a and 2b are supplied to the subtractor 3. The subtractor 3 includes a control circuit 5 described later.
In response to the control signal from, the difference between the coordinate value supplied to the A terminal and the coordinate value supplied to the B terminal or the difference between the coordinate value supplied to the B terminal and the coordinate value supplied to the A terminal is obtained. A carry signal CY indicating the magnitude relationship between both coordinate values is output. The registers 4a and 4b hold the carry signal CY supplied from the subtractor 3 and use it as an area code described later.

The control circuit 5 starts a control operation for data transfer based on an instruction from the CPU 12, and the control operation B will be described later.
In response to the signal indicating the end of data transfer supplied from the IT-BLT 7, the CPU 12 outputs an interrupt signal indicating the completion of transfer. The control circuit 5 also stores a table (described later) shown in FIG. 3, and generates selection signals for the selectors 6a and 6b according to the area codes held in the registers 4a and 4b.

In response to the control signal from the control circuit 5, the selectors 6a and 6b select the holding coordinates of the registers 1a and 1b, generate the corner coordinates of the overlapping area, and BIT-
Send to BLT7.

The BIT-BLT 7 transfers (saves) the data in the designated rectangular area in the BMM 13 to the position designated by the CPU 12. When the transfer is completed, the BIT-BLT 7 outputs a signal to that effect to the control circuit 5.

Next, the data transfer device 11 shown in FIG.
The operation will be described. First, as a premise, a region check by the Cohen-Suterland clipping algorithm used in this embodiment will be described.

FIG. 2 is a diagram of Cohen-Suterland.
It is a conceptual diagram of a region check by a clipping algorithm. In FIG. 2, window 21 (coordinates (X1
s, Y1s) to (X1e, Y1e) is used as a reference area, and the image memory (screen) is divided into nine areas. Assign a code.

Given a point (X, Y) on the image memory, by looking at the sign of the result of each calculation of Y1e-Y, Y-Y1s, X1e-X, X-X1s, the point (X , Y)
The code of the area that belongs to is determined ("0" if the sign is positive,
If it is negative, it is set to "1"), and the relative position to the window 21 is classified.

By applying this, a code is obtained for each of the corner coordinates (X2s, Y2s) and (X2e, Y2e) of the window 22 to be newly opened (to be drawn), and drawing is already performed from these two codes. Opened window 21 and newly opened window 2
The overlapping state with 2 can be detected. Next, with reference to FIG. 3, a method of obtaining the corner coordinates of the overlapping area of the windows 21 and 22 will be described.

Using the area checking method described above, the corner coordinates ((X2s, Y2s) and (X2s) of the window 22 are used.
e, Y2e)), the area code with respect to the window 21 is obtained. FIG. 3 is a table showing a combination of these two codes. As shown in FIG.
Overlapping of the window 21 and the window 22 occurs only in 16 ways, and the corner coordinates of the overlapping area at that time have the values described in the table.

In this table, the start address (coordinates) of each window is the upper left corner, the end address (coordinates) is the lower right corner, and there is no reversal of this positional relationship. When the corner coordinates of such an overlapping area are obtained, the data in this rectangular overlapping area is BIT-B.
Data in the overlapping area can be saved by copying to the free area such as the BMM 13 or the main memory 14 by the LT 7.

Next, the data transfer apparatus shown in FIG. 1 will be used to concretely describe the detection of an overlapping area using the Cohen-Sterland clipping algorithm and the saving of data.

An instruction to open a new window 22
For example, when input from a keyboard (not shown), the CPU
12 is the coordinates (X1s, Y1s) and (X1e, Y1) of the start and end points of the window 21 in the register 1a via the local bus.
e) is set, and the coordinates (X2s, Y2s) and (X2e, Y2) of the start point and the end point of the window 22 newly opened in the register 1b are set.
e) is set. Furthermore, CPU12 is BIT-BL
At T7, the address of the save destination of the data in the overlapping area (the transfer destination address in the main memory 14 in this embodiment) is designated. After that, the CPU 12 instructs the control circuit 5 to start the transfer control operation. When the above operation is completed, the CPU 1
2 performs other processing until an interrupt is received from the data transfer device 11.

The control circuit 5 causes the selectors 2a and 2b to select Y1e and Y2s in order to obtain the code of the area to which the start address (X2s, Y2s) of the window 22 to be newly opened belongs. The control circuit 5 controls the subtractor 3 to subtract Y2s from Y1e. Subtractor 3 has Y1e> Y
If it is 2s, the carry CY of "0" is output, and if Y1e≤Y2s, the carry CY of "1" is output. This carry C
Y is held in the first bit of the register 4a. Less than,
Similarly, the control circuit 5 causes the selectors 2a and 2b to select Y1s and Y2s, X1e and X2s, X2s and X1s, and the subtractor 3
Is controlled to calculate Y2s-Y1s, X1e-X2s, X2s-X1s, and the obtained carry CY is sequentially stored in the second register 4a.
Through 4th bit.

Next, the control circuit 5 controls the selectors 2a and 2b to obtain the code of the area to which the end address (X2e, Y2e) of the window 22 belongs, and controls Y1e and Y2.
Select e, Y2e and Y1s, X1e and X2e, X2e and X1s,
The subtractor 3 outputs Y1e-Y2e, Y2e-Y1s, X1e-X2e, X2e.
-Calculate X1s and store the obtained carry in register 4
It is held in the first to fourth bits of b.

The 4-bit code held in the register 4a indicates the code of the area to which the start address of the window 22 belongs, and the 4-bit code held in the register 4b indicates the code of the area to which the end address of the window 22 belongs. For example, in the case of the state shown in FIG.
The code of the area to which the start address of 2 belongs is (000
0), the code of the area to which the end address belongs is (101
0).

The control circuit 5 internally holds, for example, a start address and an endless start / end address of an overlapping area shown in FIG. 3 in the form of a table. The control circuit 5 inputs two area codes from the registers 4a and 4b, and based on the data stored therein,
If the two windows overlap, the selectors 6a to 6a
A selection signal of d is generated, and when the two windows do not overlap each other, an interrupt signal to that effect is supplied to the CPU 12. In response to this interrupt signal, the CPU 12 starts an operation (described later) for opening a new window 22.

The selector 6a receives the coordinate data X1s and X2s, selects one of X1s and X2s according to a control signal from the control circuit 5, and outputs it. Selector 6b is coordinate data Y
It receives 1s and Y2s and selects and outputs one of Y1s and Y2s according to the control signal. The selector 6c receives the coordinate data X1e and X2e and selects and outputs one of X1e and X2e according to the control signal. Selector 6d has coordinate data Y1e and Y2e
In response to the control signal, one of Y1e and Y2e is selected and output.

For example, in the state of FIG. 2, the code of the area to which the start address of the newly opened window 22 belongs is (0000), and the code of the area to which the end address belongs is (1010). Therefore, the control circuit 5 causes the selector 6a to select X2s, the selector 6b to select Y2s, and the selector 6c to select X2s in accordance with the internally held table of FIG.
1e is selected, and the selector 6d is selected Y1e.

The BIT-BLT 7 uses the values supplied from the selectors 6a and 6b as the start address X of the overlapping area,
The Y coordinate and the values supplied from the selectors 6c and 6d are recognized as the X and Y coordinates of the end address of the overlapping area.

The BIT-BLT 7 sets the data in the rectangular overlapping area to C according to the start / end address.
According to the transfer destination address supplied from the PU 12 via the local bus, it is copied to the free area of the BMM 13 or the main memory 14. Further, the BIT-BLT 7 holds the start / end address and the transfer destination address of the overlapping area.

When the data transfer is completed, BIT-BLT
7 notifies the control circuit 5 that the transfer is completed. Upon receiving this notification, the control circuit 5 supplies an interrupt signal to the CPU 12 to notify that the saving of the data in the overlapping area has been completed. In response to this interrupt signal, the CPU 12 starts an operation of opening a new window 22 (a process of writing data corresponding to the window 22 in the BMM). First, C
The PU 12 notifies the BIT-BLT 7 of the address of the area in the main memory 14 in which the data to be newly expanded is stored, with the coordinates (X1s, Y1s) and (X1e, Y1e) as the transfer destination address as the transfer source address. In response to this notification, the BIT-BLT 7 transfers the data stored in the main memory 14 to the designated area of the BMM 13 and opens the window 22. When the data to be newly drawn stored in the main memory 14 is in code format,
The BIT-BLT 7 develops this code data into a bit pattern and then transfers it.

On the other hand, when closing the window 22, CP
U12 sends an instruction to restore the saved data to BIT-BLT7. The BIT-BLT 7 restores the saved data to the original position based on the held start and end addresses of the overlapping area and the transfer destination address (save destination address).

As described above, unlike the prior art, the data transfer device 11 generates the corner coordinates of the overlapping area. Therefore, the load on the CPU is lightened and the data processing can be speeded up as compared with the conventional case.

The present invention is not limited to the above embodiment. For example, in the above embodiment, the BI is also used when transferring the data for opening a new window and restoring the saved data.
Although the T-BLT 7 transferred the data, the data may be transferred by another circuit. Further, in the above embodiment, the BMM
Although the data in the overlapping area of 13 or the free area of the main memory 14 is saved, the data may be saved in another memory. Although the subtractor 3 and its carry output are used to determine the magnitude of the data selected by the selectors 2a and 2b, other configurations may be used. For example, selector 2
The outputs of a and 2b may be supplied to the comparator, and the comparator may determine the magnitude. Further, in the above embodiment,
Although the subtraction operation of the subtractor 3 is switched by the control circuit 5, the output carry CY of the subtractor 3 may be inverted and used as needed, and what is required as long as an appropriate area code is finally obtained. Any configuration may be used.

The present invention can also be applied to various devices and methods for comparing the sizes of addresses and redefining a rectangular area address or transferring data in the rectangular area according to the result.

[0043]

According to the present invention, the data transfer apparatus itself performs the preprocessing (identification of the overlapping area) of the data transfer which is conventionally performed by the CPU itself. Therefore, the load on the CPU is reduced, and the speed of the entire display process is improved.

[Brief description of drawings]

FIG. 1 is a block diagram showing the configuration of a display system according to an embodiment of the present invention.

FIG. 2 is a diagram for explaining the relationship between two windows.

FIG. 3 is a diagram showing a relationship between a code of an area to which a start address and an end address of a newly opened window belong, and a start address and an end address of an overlapping area.

[Explanation of symbols]

1a, 1b, 4 ... Registers, 2a, 2b, 6a-6d ...
Selector, 3 ... Subtractor or comparator, 5 ... Control circuit, 7
... BIT-BLT, 11 ... Data transfer device, 12 ... CP
U, 13 ... BMM, 14 ... Main memory, 15 ... Display unit, 21 ... Window already opened, 22 ... Window to be newly opened.

Claims (5)

[Claims] 1. A display memory, which is addressable by coordinates and stores bitmap data that defines a display image, and a second window is further drawn with the first window drawn in the display memory. A central processing unit for instructing that the central processing unit is connected to the central processing unit and the display memory, and determines whether or not the first window and the second window overlap in response to an instruction from the central processing unit. Determining means for determining the coordinates of the overlapping area when it is determined that the first and second windows overlap each other, and before drawing the second window in response to the detection result of the detecting means. And a data transfer device including a notification unit for notifying the central processing unit of the completion of the saving. A data processing device having a window function. 2. The determining means and the detecting means determine a relative position of coordinates of a start point and an end point of the second window with reference to the first window, and the determined first 2. A means for determining whether or not the overlapping area is generated, and determining the coordinates of the overlapping area when the overlapping area is generated based on the relative position of the coordinates of the start point and the end point of the second window. 1. The data processing device according to 1. 3. The central processing unit notifies the data transfer unit of the coordinates of the start and end points of the first and second windows and the save destination, and the discriminating means and the detecting means include the first and second windows. The overlap area of the first and second windows is obtained based on the coordinates of the start point and the end point of the window, and the data of the overlap area is saved in the save destination, and the central processing unit The data processing device according to claim 1, wherein control for drawing the second window is started in response to the notification of the completion of the evacuation. 4. A detection unit that determines whether or not a plurality of rectangular areas defined on a memory overlap and determines an overlapping portion when they overlap, and a detection unit that is connected to the memory and the detection unit, A transfer means for transferring the data of the overlapping portion of the memory according to a detection result, and a function of identifying the overlapping portion of a plurality of rectangular areas on the memory and transferring the data of the overlapping portion. Transfer device. 5. A display memory for storing display data; a display means connected to the display memory for displaying the display data; a transfer means connected to the display memory for transferring the display data; Connected to the means for opening the second window while the first window is opened on the display means, the data transfer means includes start and end points and transfer destinations of the first and second windows. The transfer means determines whether or not the first window and the second window are overlapped in response to an instruction from the control means, and when they are overlapped, the transfer area is notified. To save the data in the overlapping area of the display memory to the save destination, notify the control means of the completion of the save, and the control means responds to the save completion notification,
A multi-window system characterized by performing control for opening the above windows.