KR100348422B1 - The apparatus for controlling the graphic display using the line control table - Google Patents

Abstract

In order to control graphics in a display device, a device for horizontal and vertical scrolling, zooming in and zooming out as well as resolution and color is required, and a storage device for storing various information is required. The present invention relates to a display control device capable of reducing the size of the memory by effectively using the memory by forming a table having information for each horizontal line in such a storage device and by using only a specific area of the screen.

Description

Graphic display control device using line control table {THE APPARATUS FOR CONTROLLING THE GRAPHIC DISPLAY USING THE LINE CONTROL TABLE}

The present invention relates to a graphic display control apparatus and method using a line control table (hereinafter referred to as LCT).

In general, m horizontal lines and n pixels are required for each horizontal line to configure one screen in a screen output device. The pixel is a minimum unit of one point of the screen, which is the maximum according to the type of color. The size is different. If there are 16 colors, 4 bits are required. If it is 256 colors, 8 bits are required. In addition, the higher the resolution of the graphic, the larger the size of m and n, and the memory required for the screen configuration is changed accordingly. Conventionally, all pixel data of one screen is stored in a specific address unit, and an address is relatively determined according to the horizontal line number and the type of pixel and color. Scrolling, zooming, and the like are also performed in the address unit. Here, the address unit generates a pixel address through a register. In order to control all the lines, the size of the system increases so that a separate register for moving / expanding / shrinking the line number and the line is required.

The prior art described above has the following problems. First, the memory required to compose a screen is predetermined. In other words, when the resolution of the screen is high or the number of colors increases, the size of the memory increases accordingly, the size and price of the system also increase, and the memory access efficiency decreases. Second, when moving the screen from side to side, you can move the entire screen, but could not move the screen of only a specific line. Although only certain lines can be moved, some other storage device and control unit are additionally required. Third, in the enlargement / reduction of the screen, it is possible to enlarge / reduce the entire screen, but it is impossible to enlarge / reduce the screen only for a specific line, and additionally, some other storage device and a controller are required. Fourth, in the case where it is desired to copy certain lines to other lines, the same pixel data must be copied to the memory and then rewritten. Therefore, the memory efficiency is lowered.

If the resolution is low and there are few kinds of colors, a lot of memory is not required, but as the resolutions are increasingly demanding high resolution and many kinds of colors, a lot of memory may be required accordingly. Thus, there is a need to increase memory access efficiency while maintaining existing memory capacity.

SUMMARY OF THE INVENTION An object of the present invention is to provide a graphic control apparatus and method using an LCT capable of effectively using a memory by forming a line control table having information for each horizontal line.

1 is a block diagram of a graphic display control device according to the present invention.

2 illustrates LCT address generation and vertical scrolling operations in accordance with the present invention;

3 illustrates a horizontal scrolling operation in accordance with the present invention.

※ Explanation of code about main part of drawing ※

10: LCT start address 20: VCOUNT generating part

30: vertical scroll control 40: line control table

50: horizontal scroll control unit

In order to achieve the above object, the present invention includes a memory unit having an LCT, wherein the LCT includes horizontal position information, pixel address information of pixel data, expand information, and in each horizontal line constituting a screen. Has enable / disable information; An LCT start address unit designated by a user; A VCOUNT generating unit generating VCOUNT through the vertical count for each horizontal line; A vertical scroll controller which controls vertical scroll by increasing or decreasing a start address of the LCT; A horizontal scroll controller which controls a horizontal scroll by using the horizontal position information of the LCT; And a screen display controller for outputting pixel data as a video signal and controlling screen display.

Hereinafter, a graphic control apparatus using a line control table of the present invention will be described in detail with reference to the accompanying drawings.

1 is a configuration diagram of a graphic display control device according to the present invention.

In Fig. 1, reference numeral 10 denotes an LCT start address that specifies an LCT start address. 20 is a VCOUNT generator that generates VCOUNT through vertical counts for each horizontal line. 30 is a vertical scroll control unit, and controls the vertical scroll by controlling the start address and VCOOUNT of the LCT. 40 indicates horizontal position information for controlling horizontal scrolling for each horizontal line, pixel address information for specifying an arbitrary address, expand information for controlling line expansion and contraction, and enable or disable output of each line. Line LCT with / Disable (Enable / Disable) information. 50 is a horizontal scroll control unit that controls horizontal scrolling by using the horizontal position information of the LCT. 60 is a screen output control unit that finally outputs a video signal.

The apparatus of the present invention configured as described above controls the screen display according to the user's key input.

Assuming that a screen consists of m horizontal lines, the LCT has a maximum of m addresses. As already mentioned, each LCT has horizontal position information, pixel address information, expand information, and enable / disable information.

The horizontal position information is used for horizontal scrolling. The screen can be moved left and right depending on how far the horizontal position is from the start of the horizontal line. Changing the value every time the screen changes will have the effect of naturally moving the screen from side to side.

The pixel address information is a start position of an address where pixel data of one horizontal line is located. If you want to copy a specific line, you can use the same pixel address value in different horizontal lines.

The expand information is used to enlarge or reduce one horizontal line. This not only enlarges / reduces the entire screen, but also enlarges / reduces specific areas only.

The enable / disable information is used to determine which one horizontal line to output on the screen. In the case of the enable, the pixel data located at the pixel address is displayed on the screen. In the case of the disable, the specific color is displayed on the screen regardless of the pixel address, and no memory access occurs. This enables overlay of the screen, which not only reduces the memory size but also increases the memory access efficiency.

When the LCT of one screen is configured, vertical scrolling may be performed by increasing or decreasing the start address of the LCT. Continually increasing the start address of the LCT scrolls up the screen, decreasing it scrolls down the screen. In addition, if the LCT address is increased or decreased by k instead of decreasing by one for each line, the vertical scroll speed can be controlled. Here, the speed of scrolling increases as the value of k decreases.

LCT address generation and vertical scrolling

The LCT start address is an address specified by the user. As can be seen in Figure 2, the VCOUNT generating unit 20 starts counting on the falling edge of the signal HSYNC of the horizontal line, and is initialized to zero when one screen is over. The LCT start address and VCOUNT are combined to generate the original LCT address with the value of TLCT [n: 0].

The vertical scroll control unit 30 is divided into a speed block 32, a scroll count block 34, and an adder block 36. The speed block 32 starts counting at every falling edge of HSYNC, and generates a carry signal whenever the count value equals the k value for adjusting the speed. The carry signal is used as an enable signal of the scroll count block 34. In this case, the smaller the value of k, the faster the carry signal is generated, thus increasing the speed of scrolling.

The scroll count block 34 starts counting in increments / decrements according to the up / down signals whenever the carry signal occurs in the speed block 32, and the value of the offset offset [n: 0] is added to the adder block ( 36). The adder block 36 generates the LCT address by summing the original LCT address and the value of offset [n: 0], and performs a vertical scroll function. If the vertical scrolling function is not used, the value of offset [n: 0] becomes 0 and the LCT address becomes the original LCT address value.

Horizontal scroll

When the first value of the pixel data is determined at which point in time, the horizontal scroll is performed. As shown in FIG. 3, the horizontal scroll controller 50 includes an HCOUNT block 52 and a comparator block 54. The HCOUNT is counted according to a dot clock (DCLK), and the value of the HCOUNT ( When B) becomes larger than the horizontal position value A, pixel data is output.

Zoom in zoom out

The enlargement / reduction is performed using the expand information of the LCT. The enlargement repeatedly outputs the pixel data, and the reduction outputs only one of the plurality of pixel data.

By controlling the graphic display using LCT, memory can be managed efficiently, resulting in reduced memory size and, consequently, reduced system size and cost. In addition, since the LCT has scroll and zoom information, it is easy to control each line, and the size of the system can be reduced because no separate device is required.

Claims (6)

A memory unit having an LCT, the LCT having horizontal position information, pixel address information of pixel data, expand information, and enable / disable information for each horizontal line constituting a screen; An LCT start address unit designated by a user; A VCOUNT generating unit generating VCOUNT through the vertical count for each horizontal line; A vertical scroll controller which controls vertical scroll by increasing or decreasing a start address of the LCT; A horizontal scroll controller which controls a horizontal scroll by using the horizontal position information of the LCT; And a screen display control unit for outputting pixel data as a video signal and controlling the screen display. The speed block of claim 1, wherein the vertical scroll control unit starts a count for each falling edge of HSYNC and generates a carry signal whenever the count value is equal to the k value for adjusting the speed, when the carry signal is generated in the speed block. And a scroll count block for starting counting by increasing / decreasing in accordance with an up / down signal and an adder block for generating an LCT address by summing an original LCT address and an LCT address offset value. . The method of claim 1, wherein the horizontal scroll control unit further comprises a HCOUNT block for generating an HCOUNT reset on the falling edge of HSYNC and a comparator block for comparing the HCOUNT value and the horizontal position value, wherein the HCOUNT value is greater than the horizontal position value. And a pixel data output to the screen display control device. The method of claim 1, wherein the enlargement and reduction of a predetermined line is based on the expand information of the LCT, wherein the enlargement of the predetermined line is repeatedly outputted predetermined pixel data, and the reduction of the predetermined line is performed by only one of a plurality of pixel data. Display control device characterized in that for outputting. The pixel address information of the LCT is a start position of an address where pixel data of one horizontal line is located, and the same pixel address value is used in another horizontal line when a specific line is to be copied. Display control device. The method of claim 1, wherein the enable / disable information of the LCT is used to determine which one horizontal line is to be output to the screen. And displaying and disabling a specific color regardless of the pixel address.