JPH08106274A - Method and device for cursor display - Google Patents

Abstract

PURPOSE: To continuously move and to delete a cursor in accordance with the motion of the cursor even though the display starting position of the cursor is located in the negative portion of an x coordinate on a display. CONSTITUTION: Cursor data supplied through a data bus 1 are stored in a RAM 3. The data corresponding to the coordinates on the screen specified by a mouse not shown in the diagram are outputted to a cursor display position/shift number detection section 4 through the bus 1 and an MPU interface section 2. Based on the coordinates data, the section 4 computes a shift bit number and a jumping step number and supply them to an output format section 5. The section 5 shifts the cursor data outputted from the RAM 3 in parallel for the amount of the shift bit number, divides into plural steps, inputs in a 5 or a 4 bit unit and outputs the data after a prescribed step at a prescribed position on the screen with a 5, 4 or 1 bit unit.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cursor display method and apparatus suitable for use in, for example, a cursor generator for displaying a cursor of a predetermined size at a predetermined position on a graphic screen.

[0002]

2. Description of the Related Art The display frequency per pixel of a monitor such as a personal computer is usually 400.times.400 (pixels) .times.60 (frames / second), that is, about 15 (MH) effective.
Since z) is sufficient, it is possible to output only one pixel. On the other hand, the display frequency per pixel of a high-resolution monitor in a workstation or the like is required to be approximately 1280 × 1024 (pixels) × 60 (frames / second), that is, approximately 80 (MHz) effective. It is not practical when outputting only one pixel.

Therefore, in a high resolution monitor such as a workstation, the effective frequency is increased by 4 times or 5 times by outputting 4 or 5 pixels in one clock.

In the conventional cursor generator,
For example, 64 × 64 corresponding to a cursor having a predetermined shape in order to increase the effective frequency by a factor of 4 or 5
Store the bit data in RAM, shift it by a predetermined number of bits corresponding to the cursor display position,
The image is output on the screen at a predetermined timing.

FIG. 13 is a diagram showing an example of a graphic screen. In FIG. 13, the blanking area B is defined as a predetermined area surrounding the display area A and outside the display area. The data output to the display area A is displayed, and the data output to the blanking area B is not displayed.

The horizontal width of the blanking area B on the left side of the display area A is defined as the horizontal back porch a, and as described above, the data output to this portion is not displayed.

Therefore, the cursor L having a predetermined size is output so as to extend over the display area A and the blanking area B as shown in FIG. 13 and so that the left end of the cursor L is within the blanking area B. In this case, the x-coordinate (horizontal coordinate) of the cursor display start position has a positive value and is normally displayed.

On the other hand, as a result of the cursor M ₁ having a predetermined size larger than the horizontal back porch a in the horizontal direction of the cursor translated in the -x-axis direction, its display start position is 0 in the x-coordinate. When it comes to be located in the negative area on the left side, the data of the portion located in the negative area of the x coordinate of the cursor M ₁ is output to the position indicated by the cursor M ₂ on the right side of the screen. Then, when the amount of data in that portion increases, a part of the corresponding cursor is displayed in the display area A.

This is because, for example, the x coordinate of the screen is represented by 12 bits, that is, it is represented by a numerical value from 0 to FFF.
If the x-coordinate FFF corresponds to the right edge on the screen, x
Coordinate -1 is the FFF as the result of subtracting 1 from 0
It depends on.

On the other hand, the portion of the x-coordinate of the cursor M ₁ which is greater than 0 disappears from the screen at that moment. This is because the portion from the falling edge to the rising edge of the horizontal synchronizing signal is in the horizontal blanking period, so that the cursor data display start position cannot be detected and the cursor data is not displayed on the screen.

[0011]

As described above, in the conventional cursor generator, when the display start position of the cursor is located on the left side of the blanking area B, the x coordinate value of the display start position of the cursor takes a negative value. The problem is that the cursor moves discontinuously to other positions on the screen.

The present invention has been made in view of such a situation. As the display start position of the cursor continuously moves to the left side of the blanking area B, the cursor continues from the display area A. It is intended to be able to disappear.

[0013]

According to a first aspect of the present invention, there is provided a cursor display method, wherein cursor data corresponding to a cursor having a predetermined size displayed on a screen is stored, and the cursor data of the cursor data is stored. While the data corresponding to a predetermined horizontal 1 line is shifted by a predetermined number of bits corresponding to the display start position of the cursor on the screen,
It is input and stored in parallel by dividing it into a plurality of steps in units of a predetermined number of input bits, and is input after a predetermined step among the plurality of steps corresponding to the display start position of the cursor on the screen. The data is output to a predetermined position on the screen in units of a predetermined output bit number.

In the cursor display method according to the second aspect, when the display start position of the cursor on the screen is within the area of the screen, all the data is output on the screen and the display start of the cursor on the screen is started. If the position is outside the screen area,
Only the data input after the predetermined step in the predetermined input bit number unit can be output to the predetermined position on the screen in the predetermined output bit number unit.

According to a third aspect of the present invention, there is provided a cursor display device, which stores a cursor data corresponding to a cursor having a predetermined size which is displayed on the screen (for example, the RAM 3 in FIG. 1) and the cursor data. Among them, while shifting the data corresponding to a predetermined horizontal 1 line of the cursor by a predetermined number of bits corresponding to the display start position of the cursor on the screen, a plurality of steps are provided in units of a predetermined number of input bits. Of the plurality of steps corresponding to the parallel input storage means (for example, the parallel-in-serial-out type shift register 11 in FIG. 3) for inputting and storing in parallel to each other and the display start position of the cursor on the screen. Output means for outputting data input after a predetermined step to a predetermined position on the screen in a predetermined output bit number unit (for example, in FIG. Multiplexers 22a-22
e) is provided.

According to another aspect of the cursor display device of the present invention, the display start position of the cursor on the screen is changed by the output means.
If it is within the area of the screen, all data is output on the screen in units of the specified number of output bits, and if the display start position of the cursor on the screen is outside the area of the screen, in units of the specified number of input bits. Only the data input after the predetermined step can be output on the screen in units of a predetermined output bit number.

[0017]

In the cursor display method or apparatus according to claim 1 or 3, cursor data corresponding to a cursor having a predetermined size displayed on the screen is stored, and the cursor data among the cursor data is stored. The data corresponding to a predetermined horizontal 1 line of is shifted by a predetermined number of bits corresponding to the display start position of the cursor on the screen, and is divided into a plurality of steps in units of a predetermined number of input bits in parallel. Is input and stored in. Further, only the data input after the predetermined step among the plurality of steps corresponding to the display start position of the cursor on the screen is output on the screen in a predetermined output bit number unit. Therefore, only the cursor data corresponding to the predetermined portion of the cursor can be output.

In the cursor display method or apparatus according to claim 2 or 4, when the display start position of the cursor on the screen is within the area of the screen, all the data is output on the screen and the cursor is displayed. If the display start position on the screen is outside the screen area, only the portion located within the screen area is displayed on the screen. Therefore, even when the display start position of the cursor is located at the negative x coordinate outside the screen area, the portion located within the screen area is displayed.

[0019]

1 is a block diagram showing the configuration of an embodiment of a cursor generator to which the cursor display method and apparatus of the present invention are applied. The MPU (microprocessor unit) interface unit 2 is connected via a data bus 1 to a host computer (not shown) and a RAM 3 which is a memory that operates relatively slowly.

Further, the MPU interface unit 2
When coordinate data corresponding to a predetermined point on a CRT screen (not shown) designated by a pointing device such as a mouse (not shown) connected to a host computer is supplied via the data bus 1, Is set to the internal register and output.

The RAM 3 stores cursor data, which is supplied from the host computer through the data bus 1 and has a size of, for example, 64.times.64 pixels corresponding to a cursor having a predetermined shape, and outputs it at a predetermined timing. It is designed to do. Further, the RAM 3 is a RAM supplied from a cursor display position / shift number detection unit 4 described later.
Predetermined cursor data is supplied to the output format section 5 in synchronization with the output clock signal.

The cursor display position / shift number detector 4
In FIG. 9, an x-coordinate decoder 21 and the like described later are provided,
Clock signal (ck), horizontal synchronization signal (hsync),
To detect the cursor display position based on the vertical synchronization signal (vsync) and the coordinate data supplied from the MPU interface unit 2, supply a predetermined RAM output clock signal to the RAM 3 and display the cursor at that position. In addition, shift bit information indicating the number of shifts when shifting cursor data supplied from the RAM 3 to the output format unit 5 described later is obtained from the coordinate data,
It is adapted to be supplied to the output format section 5.

The output format section 5 is composed of a parallel-in / serial-out type shift register 11 which will be described later with reference to FIG. 3, and based on the shift bit information supplied from the cursor display position / shift number detecting section 4, R
Cursor data supplied in parallel from AM3 is input in parallel while shifting by a predetermined number of bits.
The data input after the predetermined step is divided into a plurality of steps in units of the number of input bits, and is output in units of the predetermined number of output bits.

Next, the operation will be described. First, the cursor data corresponding to a predetermined cursor is transferred from the host computer to the RAM 3 via the data bus 1.
This data is stored in the RAM 3.

Next, data corresponding to a predetermined coordinate position on, for example, a CRT designated by a pointing device such as a mouse connected to the host computer is supplied to the MPU interface unit 2 via the data bus 1. .

The MPU interface unit 2 writes the data corresponding to the predetermined coordinate position on the screen of the CRT supplied from the host computer via the data bus 1 into the register, and then the cursor display position / shift number detection unit 4 Supply to.

The cursor display position / shift number detector 4
The corresponding x coordinate on the screen is detected by counting the clock signal (ck), and the horizontal synchronization signal (hsyn) is detected.
The corresponding y coordinate on the screen is detected by counting c). The detected x and y coordinates are compared with the coordinate data supplied from the MPU interface unit 2, and when they match each other, a predetermined RAM output clock signal is generated and supplied to the RAM 3.

When the RAM output clock signal is supplied from the cursor display position / shift number detection unit 4, the RAM 3 stores data (64 bits) corresponding to a predetermined horizontal line of the cursor data stored therein. , 4 bits or 5 bits are supplied in parallel to the output format section 5.

Here, an arbitrary position on the screen (however, x
The coordinates will be described as positive), and the concept of the shift necessary when outputting predetermined pixel data for each 5 pixels that cannot be represented by 2 ⁿ will be described.

FIG. 2A shows a timing relationship between pixel data and a clock signal output at a predetermined x coordinate on the screen. In this case, data for 5 pixels is output per clock. For example, when the pixel data shown in FIG. 2B is output on the screen with the position of the third pixel from the left of the pixel data shown in FIG. 2A as the display start position, the clock signal must be changed. Therefore, as shown in FIG.
After shifting the pixel data shown in (a) by 2 bits to the right, as shown in FIG. 2 (c), the pixel data is output to the screen in units of 5 pixels in synchronization with the clock signal. In addition, in the figure, the black portion indicates an empty output.

Thus, even in the method of simultaneously outputting a plurality of pixels to the screen in one clock by shifting the pixel data by a predetermined number of bits, the predetermined pixel data can be output to an arbitrary position on the screen. Is possible.

FIGS. 3 (a) to 3 (e) respectively show the construction of one embodiment of the parallel-in / serial-out type shift register which constitutes the output format section 5 of FIG. As described above, the parallel-in / serial-out type shift register 11 includes five shift registers 11a to 1a.
1e, and shift registers 11a to 11c
17 bits, the shift register 11d can store 16 bits, and the shift register 11e can store 13 bits of pixel data.

As will be described later, when the output format section 5 outputs 4 pixels per clock, it is necessary to store data for 64 pixels in four registers 11a to 11d. Considering the case of further shifting by 3 bits, the shift registers 11 a to 1
1c requires 17 bits and shift register 11d requires 16 bits.

When the output format section 5 outputs 5 pixels per clock, 13 bits are required for the shift register 11e.

Therefore, the shift register 11 has a total of 80
The shift register is composed of (= 17 × 3 + 16 + 13) bits. As a result, 64-bit pixel data can be stored even when outputting 4 or 5 pixels per clock.

In the output format section 5, based on the shift bit information supplied from the cursor display position / shift number detection section 4, 64-bit cursor data (pixels) for one horizontal line shown in FIG. data)
Are supplied in parallel by 5 or 4 bits, and after being shifted by a predetermined number of bits (corresponding to the display position) as described with reference to FIG. 2, the corresponding ones of the shift registers 11a to 11e. Input to each thing.

As shown in FIG. 4, for convenience of explanation, RAM
Identification numbers of 0 to 63 are added to the 64-bit pixel data for one predetermined horizontal line of No. 3, respectively.

Next, referring to FIGS. 3 (a) to 3 (e),
A storage method when the pixel data supplied from the RAM 3 is stored in the parallel-in / serial-out type shift register 11 when the number of pixels output from the output format section 5 is 5 per clock will be described.

In FIG. 3A, the cursor data supplied from the RAM 3 is the same as the shift registers 11a to 1a.
The arrangement of pixel data when supplied to 1e (when the number of shift bits in FIG. 2 is 0) is shown, and similarly,
3B shows a case where the number of shift bits is 1, FIG. 3C shows a case where the number of shift bits is 2, FIG. 3D shows a case where the number of shift bits is 3, and FIG. 3E shows a case where the number of shift bits is 4. The arrangement of the pixel data of is shown respectively.

The number of shift bits described above is determined by a predetermined method depending on the display position of the pixel data on the screen. For example, when the display start position of the pixel data is a positive x-coordinate position, it is shifted by an amount corresponding to the remainder divided by 5, and a predetermined X-coordinate position (x-coordinate position represented by a multiple of 5) From 5 per clock
Output pixel by pixel. By doing so, predetermined pixel data can be output to a predetermined x coordinate position.

5A to 5D, the number of pixels output from the output format section 5 is 4 per clock.
FIG. 6 is a diagram for explaining a storage method when pixel data supplied from a RAM 3 in the case of pixels is stored in a parallel-in / serial-out type shift register 11. In this case, the shift register 11e is not used.

In FIG. 5A, the pixel data supplied from the RAM 3 is the same as that of the shift register 11.
The arrangement of the pixel data when supplied to a to 11e (when the number of shift bits is 0) is shown, and similarly, FIG.
The arrangement of pixel data when the number of shift bits is 1 in FIG. 5B, the number of shift bits is 2 in FIG. 5C, and the number of shift bits is 3 is shown in FIG. 5D. There is.

Similar to the case of outputting 5 pixels per clock, the above-mentioned shift bit number is determined by a predetermined method depending on the display position of the pixel data on the screen. For example, the display start position of pixel data is
If it is a positive x-coordinate position, it is shifted by an amount corresponding to the remainder divided by 4, and 4 pixels are output per clock from a predetermined x-coordinate position (x-coordinate position represented by a multiple of 4). . By doing so, predetermined pixel data can be output to a predetermined x coordinate position.

Further, when the output format section 5 outputs predetermined pixel data one pixel per clock, as in the case where four pixel data is output per clock, the shift registers 11a to 11a shown in FIG. Predetermined pixel data is set in 11d. Then, for example, by using a 2-bit counter, the shift register 1
1a to 11d are validated one by one in this order, and pixel data are sequentially output from the validated shift register.

Next, as shown in FIG. 6, a negative x on the screen is displayed.
A method will be described in which, when the cursor N is output at the coordinate position, the portion of the cursor N located at the negative x coordinate is not displayed and only the portion of the cursor N located at the positive x coordinate is displayed.

First, a case where the number of output pixels per clock is 5 will be described. It is assumed that the cursor N is composed of 64 × 64 pixels, and attention is paid to one predetermined horizontal line composed of 64 pixels. The pixel data for one horizontal line is shifted by a predetermined number of bits,
It is set in the shift registers 11a to 11e in the state as shown in any of FIGS.

Since the portion of the cursor N located at the negative x coordinate does not have to be displayed on the screen, the pixel data set in the shift registers 11a to 11e are skipped by a predetermined number of pixels, You need to make it output to the screen.

The relationship between the number of shift bits and the number of interlaced steps in this case is expressed as shown in FIG. In FIG. 7, -1 to -64 represent the display start x-coordinate of the cursor, and the shift numbers S0 (shift number 0) to S4 (shift number 4) are determined correspondingly. Similarly, the interlaced step number sti (step number i) of the pixel data is determined corresponding to the display start x coordinate of the cursor.

For example, assuming that the x coordinate of the display start position P of the cursor N is -1 in FIG. 6, from FIG.
The number of interlaced steps is 1, and the number of shift bits is S
4, that is, 4 bits. Therefore, the pixel data is set in the shift registers 11a to 11e in the state shown in FIG.

Since the number of interlaced steps is 1, pixel data 0 is not output in FIG. 3 (e), and pixel data after pixel data 1 is 5 pixels per clock from the position of x coordinate 0. Is output.

As described above, even when the display start position of the cursor is a negative x coordinate, the portion corresponding to the display area A is displayed without suddenly disappearing from the screen as in the conventional case. can do.

[0052] Unlike the case of output five pixels as a number that is not represented by 2 ⁿ per clock as described above, 4 as the number represented by 2 ⁿ per clock
Alternatively, when outputting one pixel at a time, it is possible to easily obtain the shift bit number and the interlacing step number when the display start x coordinate of the cursor is negative as shown in FIG. it can.

The x coordinate of the screen is represented by 6 bits in correspondence with the size of the cursor (64 pixels in each of the vertical and horizontal directions). Display start position P of the cursor N shown in FIG.
If the x coordinate of -1 is -1, first, the 1's complement of -1 is calculated. Since -1 is represented by a binary number 111111, the one's complement of -1 is represented by 000000. This is divided into upper 4 bits and lower 2 bits, and the value obtained by adding 1 to the value represented by the upper 4 bits corresponds to the number of interlaced steps, and the value represented by the lower 2 bits corresponds to the number of shift bits. .

The number of shift bits corresponds to 3 bits when the lower 2 bits are 00, 2 bits when the lower 2 bits are 01, 1 bit when the lower 2 bits is 10, and 0 bit when the lower 2 bits are 11. To do.

In this case, the one's complement of -1 (00000
Since the lower 2 bits of 0) are 00, they are shifted by 3 bits. Further, since the upper 4 bits are 0000 (= 0), 1 obtained by adding 1 thereto is the number of interlaced steps.

Therefore, the pixel data is set in the shift registers 11a to 11d in the state as shown in FIG. 5 (d), and the pixel data 0 out of these pixel data is not output, that is, one step is skipped. Is
Pixel data after pixel data 1 is output.

By doing so, the cursor is moved to x
Even when the cursor moves to the negative area of the coordinates, the cursor does not suddenly disappear from the screen as in the conventional case, but can disappear continuously from the display screen A.

FIG. 9 is a diagram for explaining the detailed structure of the output format section 5 of FIG. 1 and its output operation. Each shift register 11a of the parallel-in-serial-out type shift register 11 that constitutes the output format unit 5
Multiplexers 22a to 22e are provided in correspondence with the respective units 11 to 11e. As will be described later, the x-coordinate decoder 21 supplies the number of interlaced steps to the multiplexers 22a to 22e.

In each shift register, for example, the shift register 11a, as shown in FIG.
Not only the pixel data corresponding to the identification numbers 0 to 60 are serially input via a, but pixel data 5 and subsequent pixel data (pixel data 5, 1
0, 15, ..., 60) are serially input to the multiplexer 22a via a predetermined connection line 32a.

By doing so, for example, pixel data 0 is not output, and only pixel data 5 and subsequent data can be output.

Similarly, although not shown in detail, the pixel data after the pixel data 10 is also serially supplied to the multiplexer 22a via any one of the predetermined connection lines 33a to 37a. ing. That is, all the pixel data set in the shift register 11a can be supplied in parallel to the multiplexer 22a via a predetermined connection line.

The multiplexer 22a can selectively output a predetermined one of the data supplied in parallel from the shift register 11a.

On the other hand, the x-coordinate decoder 21 constituting the cursor display position / shift number detection unit 4 in FIG. 1 calculates the number of interlaced steps based on the x-coordinate corresponding to the cursor display start position, and causes the multiplexer 22a to operate. Supply.
As a result, the multiplexer 22a sequentially outputs only the pixel data supplied via the predetermined connection line among the pixel data supplied from the shift register 11a. That is, the pixel data is output by skipping a predetermined number of steps.

Since the operations of the shift registers 11b to 11e and the multiplexers 22b to 22e are basically the same as those described above, the description thereof will be omitted.

For example, when outputting cursor data,
When the display start x-coordinate takes a negative value, RA is calculated based on the cursor display start x-coordinate as described above.
The cursor data supplied from M3 is set in the shift registers 11a to 11e while being shifted by a predetermined number of bits, and the shift register 1 is skipped by the number of interlaced steps obtained by the x coordinate decoder 21.
The cursor data from 1a to 11e is output in 5-bit units, for example.

At this time, output of cursor data is started at the time of rising of the horizontal synchronizing signal (the position of the left end portion of the area B in FIG. 6), and the display start x coordinate and the clock (ck) signal are changed as in the conventional case. When the x-coordinate obtained by the count matches, the process of starting the output of the cursor data is not performed.

As a result, even when the display start x coordinate of the cursor takes a negative value, the display x of the cursor data is displayed.
It is possible to display the portion where the coordinate has a positive value on the screen.

Therefore, even when the cursor display start position moves from the positive x coordinate position to the negative x coordinate position,
The cursor no longer suddenly disappears from the screen as in the past, only the part located at the negative x coordinate position,
It can be made to disappear continuously (sequentially) from the screen.

FIG. 11 is a block diagram showing the configuration of another embodiment of the cursor generator to which the cursor display method and apparatus of the present invention are applied. In this example,
Two cursor planes 41, 42 for displaying cursors
have. The horizontal / vertical counter 41a counts and outputs a horizontal synchronizing signal and a vertical synchronizing signal, respectively. The coordinate / command register 41b is
From the count value supplied from the horizontal / vertical counter 41a, the x and y coordinates on the screen are detected and stored, and
Predetermined x, y coordinate data on the screen designated by a pointing device such as a mouse supplied from a host computer (not shown), prescribed commands, cursor data, etc. are stored.

The comparison control unit 41c compares the count value stored in the coordinate / command register 41b with the x, y coordinate data, and outputs a predetermined signal when they match.

The horizontal / vertical counter 41a, the coordinate / command register 41b, and the comparison controller 41c correspond to the cursor display position / shift number detector 4 in FIG.

The RAM 41d stores cursor data supplied from the host computer and outputs it at a predetermined timing. Output format section 4
1e corresponds to the output format section 5 in FIG.
The cursor data supplied from the RAM 41d is changed to 5, 4
Alternatively, the data is output in 1-bit units from an output terminal CUR0 connected thereto via ports A to E (not shown).

Next, its operation will be described. Horizontal synchronizing signal (HSYNC) and vertical synchronizing signal (VSYNC).
Are supplied to the horizontal / vertical counter 41a, where they are respectively counted. The counted number is supplied to the coordinate / command register 41b at any time, and the x, y coordinate position on the screen is detected.

On the other hand, an address signal corresponding to the x, y coordinate position on the screen supplied from a pointing device such as a mouse connected to the host computer or command data from the host computer is supplied to the coordinate / command register 41b. And stored there.

Next, the x / y coordinates on the screen detected by the coordinate / command register 41b based on the count number supplied from the horizontal / vertical counter 41a and the x, y coordinates supplied from the host computer. Are compared by the comparison control unit 41c, and if they match, RA
The cursor data supplied from the M41d to the output format section 41e is output from the output terminal CUR0 at a predetermined timing.

The structure and operation of the cursor plane 42 are basically the same as the case of the cursor plane 41 described above, and therefore the description thereof is omitted.

By thus preparing two cursor planes, it becomes possible to handle color information.

FIG. 12 shows a video sync signal / cursor generator 52 including the above-mentioned two cursor planes 41 and 42, a RAMDAC (RAM Digital).
Analog Converter) 53, and V
A connection diagram of a RAM (Video RAM) 51 is shown.

The VRAM 51 stores pixel data corresponding to a predetermined image displayed on the screen, and the RAMDAC
The signal is supplied to predetermined input terminals P0 to P7 of 53. Each of the input terminals P0 to P7 is connected to one of the ports A to E (not shown), and the pixel data supplied to the input terminals P0 to P7 is displayed in a display color corresponding to each port.

The video sync signal / cursor generator 52 outputs a sync signal (SYNC) such as a horizontal sync signal or a vertical sync signal, supplies the sync signal to the RAMDAC 53, and causes the cursor plane 41 or the cursor plane 42 to select a predetermined cursor. The data is output.
At this time, the cursor data is output from predetermined ones of the ports A to E by 5, 4, or 1 pixel at a time, as described above, in accordance with an instruction from the host computer.

The cursor data output from the output terminal CUR0 or CUR1 is supplied to the input terminal OL (Overlay Port) 0 or OL1 of the RAMDAC 53, respectively. At this time, the input terminal OL0 or O
The cursor data input to L1 is input from the predetermined ports A to E by 5, 4, or 1 pixel by an instruction from the host computer.

The digital cursor data supplied to the input terminal OL0 or OL1 of the RAMDAC 53 is then converted into the corresponding analog cursor data,
Further, it is converted into an RGB signal and then output.

As a result, a cursor having a predetermined shape corresponding to the cursor data is displayed at a predetermined position on the screen. If one cursor is represented by the two cursor data supplied to the input terminals OL0 and OL1, each pixel forming the cursor is represented by 2 bits. Therefore, 2 ⁿ (= 4) display colors can be associated with each pixel, and the cursor can be displayed in color.

As described above, the portion of the cursor located at the positive x coordinate is displayed on the screen even when the x coordinate of the display start position has a negative value. That is, in FIG. 6, even if the x coordinate of the display start position P takes a negative value as the cursor N moves to the left of the screen, the cursor suddenly changes to the screen as in the conventional case. It is possible to continuously (sequentially) disappear from the display area A without disappearing from the display area A.

Although each embodiment has one or two cursor planes, it may have three or more cursor planes.

Further, in each of the above embodiments, the number of shift registers is five, but it is also possible to use any other number.

[0087]

According to the cursor display method or apparatus of the first or third aspect, the cursor data corresponding to a cursor having a predetermined size displayed on the screen is stored, and the cursor data is stored. Of these, the data corresponding to a predetermined horizontal 1 line of the cursor is shifted by a predetermined number of bits corresponding to the display start position of the cursor on the screen, and is divided into a plurality of steps in units of a predetermined number of input bits. It is divided and input in parallel and stored. Further, in correspondence with the display start position of the cursor on the screen, only the data input after the predetermined step among the plurality of steps is output on the screen in a predetermined output bit number unit. Therefore, only a predetermined portion of the cursor can be displayed on the screen.

According to the cursor display method or apparatus of claim 2 or 4, when the display start position of the cursor on the screen is within the area of the screen, all the data is output on the screen, When the display start position of the cursor on the screen is outside the screen area, only the part located within the screen area is displayed on the screen. The portion located within the area of the screen is displayed even if it is located at the negative x coordinate of. Therefore, with the addition of a simple device, the cursor can be made to disappear continuously from the screen as the cursor moves to the area corresponding to the negative x coordinate on the screen.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of an embodiment of a cursor generator to which a cursor display method or device of the present invention is applied.

FIG. 2 is a diagram for explaining a method of displaying predetermined pixel data at a predetermined position on a screen in units of a plurality of pixels.

FIG. 3 is a parallel-in case of outputting in units of 5 bits.
It is a figure for demonstrating operation | movement of a serial-out type shift register.

FIG. 4 is a diagram showing pixel data for a predetermined horizontal 1 line of cursor data stored in a RAM 3;

FIG. 5 is a diagram for explaining the operation of the parallel-in / serial-out type shift register when outputting in units of 4 or 1 bit.

FIG. 6 is a diagram illustrating a method of displaying a cursor on a screen.

FIG. 7 is a diagram showing the relationship between the display start position on the screen, the number of display bit shifts, and the number of interlaced steps when cursor data is output in 5-bit units.

FIG. 8 is a diagram illustrating a method of obtaining a display bit shift number and an interlace step number from a display start position on a screen when cursor data is output in units of 4 or 1 bit.

FIG. 9 is a diagram for explaining a detailed configuration of an output format section and its output operation.

FIG. 10 is a diagram for explaining a detailed configuration of an output format section and its output operation.

FIG. 11 is a block diagram showing the configuration of another embodiment of a cursor generator to which the cursor display method or device of the present invention is applied.

12 is a diagram showing an example in which the embodiment of FIG. 11 and a RAMDAC 53 are connected.

FIG. 13 is a diagram for explaining a conventional cursor display method.

[Explanation of symbols]

1 Data Bus 2 MPU Interface Section 3 RAM 4 Cursor Display Position / Shift Number Detection Section 5 Output Format Section 11 Parallel-In-Serial-Out Type Shift Register 11a, 11b, 11c, 11d, 11e Shift Register 21 x Coordinate Decoder 22a, 22b, 22c, 22d, 22e Multiplexers 31a, 32a, 33a, 34a, 35a, 36a, 3
7a Connection line 41, 42 Cursor plane 41a, 42a Horizontal / vertical counter 41b, 42b Coordinate / command register 41c, 42c Comparison control unit 41d, 42d RAM 41e, 42e Format unit 51 VRAM 52 video sync signal / cursor generator 53 RAMDAC

Claims (4)

[Claims] 1. Cursor data corresponding to a cursor having a predetermined size displayed on a screen is stored, and among the cursor data, a predetermined horizontal direction 1 of the cursor is stored.
Data corresponding to a line is input in parallel in a plurality of steps in units of a predetermined input bit number while being shifted by a predetermined number of bits in correspondence with the display start position of the cursor on the screen. Then, the data input after a predetermined step among the plurality of steps corresponding to the display start position of the cursor on the screen is displayed on the screen in units of a predetermined output bit number. The method for displaying a cursor is characterized in that the cursor is output to a predetermined position. 2. When the display start position of the cursor on the screen is within the area of the screen, all the data is output on the screen in the unit of the predetermined output bit number, When the display start position on the screen is outside the area of the screen, only the data input after the predetermined step in the predetermined input bit number unit is stored in the predetermined position on the screen. The cursor display method according to claim 1, wherein the cursor is output in units of the predetermined number of output bits. 3. A storage unit for storing cursor data corresponding to a cursor having a predetermined size displayed on a screen, and the cursor data stored in the storage unit,
Data corresponding to a predetermined horizontal 1 line of the cursor,
Parallel input storage in which the cursor is shifted by a predetermined number of bits in correspondence with the display start position of the cursor on the screen and is input in parallel in a plurality of steps in units of a predetermined number of input bits and stored. Means, and corresponding to a display start position of the cursor on the screen, the data input after a predetermined step among the plurality of steps is output in a predetermined output bit unit in a predetermined unit on the screen. And a means for outputting to the position of the cursor display device. 4. When the display start position of the cursor on the screen is within the area of the screen, the output means outputs all the data on the screen in the unit of the predetermined output bit number. When the display start position of the cursor on the screen is outside the area of the screen, only the data input after the predetermined step in the predetermined input bit number unit is displayed on the screen. The cursor display device according to claim 3, wherein the predetermined number of output bits is output to each unit.