JPS63127287A - Cursor display system - 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] [Summary] The present invention solves the problem of having a dedicated memory for storing the cursor shape in a cursor display on a display device. By storing cursor shape data in memory, a dedicated memory is not required.

[Industrial application field]

The present invention relates to cursor display on a display device, and more particularly to a cursor display method in which cursor pattern data is also stored in a video memory that stores two image data in a display device using a bitmap method.

[Conventional technology]

FIG. 6 shows a block diagram of a conventional cursor display system.

In FIG. 6, a video memory 30 stores image data for displaying an image, and a cursor memory 31 stores the shape of a cursor. The control circuit 32 generates a synchronizing signal for the display, gives the address of image data for displaying nine images on the video memory 30, and generates a cursor display signal if the cursor is displayed at a cursor display position on one display screen.

The counter 33 counts each time a cursor display signal is applied from the control circuit 32, and provides the cursor memory 31 with the address of the cursor pattern data in each rask cycle of the CRT 37.

According to the generated synchronization signal, it is converted into bit serial data and sent out. The video signal creation circuit 36 synthesizes the image data converted into bit-serial data by the parallel-to-serial conversion circuits 34 and 35 and the cursor data.

The display section 37 displays the information.

[Problems to be solved by the invention]

According to the above-mentioned prior art, an independent memory device is required to store cursor pattern data, and many devices are required for control.

[Means to solve the problem]

FIG. 1 shows a block diagram of the principle of the cursor display method of the present invention.

In FIG. 1, a video memory 1 stores in advance images for displaying images (image data and cursor pattern data, that is, font data indicating the shape of the cursor). At the same time, a cursor display signal is output according to this synchronization signal and the cursor position on the display screen, and the video memory 1
The address of the image data and the address of the cursor pattern data are given to the cursor.

The register 3 stores and holds the cursor pattern data read out from the video memory 1, and the first parallel-to-serial converter 4 stores the cursor pattern data in the register 3 according to the cursor display signal output from the video memory control section 2. This converts the cursor pattern data into bit serial data and outputs it.

The second parallel-to-serial converter 5 converts the image data read from the video memory 1 into bit serial data according to the synchronization signal output from the video memory controller 2, and outputs the bit serial data. 1 synthesizes the cursor pattern data and image data converted into bit-serial data by the first parallel-to-serial converter 4 and the second parallel-to-serial converter 5, and creates a video signal to be output to the display unit 7. It is.

[Effect]

Regarding the cursor display operation in the cursor display method of the present invention, the operation of each functional block shown in FIG. 1 will be described below.

For example, if one display section 7 uses a raster scan method, the raster display cycle will be as follows.

The video memory control unit 2 is giving the video memory 1 an address from which to read image data.

The signal is displayed on the display unit 7 via the second parallel-to-serial converter 5 and the video signal generation circuit 6.

Here, when displaying the cursor in the display cycle of a certain raster, a period 1 that does not interfere with the operation of reading image data from the video memory 1, for example, a retrace cycle of the raster, is used, and the video memory controller 2 Give the address to read the cursor pattern data to 1,
Cursor pattern data is stored in register 3. Next, while displaying the image data in the video memory 1 in the raster display cycle, the cursor pattern data in the register 3 is transferred to the first parallel-serial converter 4 and the video memory according to the cursor display signal output from the video memory control unit 2. By displaying via the signal generation circuit 6, a cursor is displayed at the desired screen position.

As described above, according to the present invention, the cursor pattern is read out in the video memory 1 while avoiding the image data access period, and is temporarily stored in the register 3 and combined with the image data to be displayed, thereby changing the conventional cursor pattern. This eliminates the need for memory for storage.

〔Example〕

FIG. 2 shows a first embodiment of the present invention.

In FIG. 2, the same reference numerals as in FIG. 1 are the same functional blocks.

In FIG. 2, two video memory control units 2 are displayed.

The display control unit 11 outputs a synchronization signal for the display unit 7 and also outputs a synchronization signal for the image data stored in the video memory 1.
Outputs the address of the data to be displayed.

At the cursor display position, a cursor display signal is output. The counter 12 follows the display control unit 11,
It outputs an address for cursor pattern data stored in the video memory 1. The multiplexer 13 selects either the address output by the display control section 11 or the address output by the counter 12 in accordance with a synchronization signal.

FIG. 3 shows a sequence diagram of the first embodiment.

In FIG. 3, a dot clock and a clock (not shown in FIG. 2) are connected to the first and second parallel-to-serial converters 4, respectively.
．． 5, the display control unit 11, and the counter 12, and the synchronization signal is a horizontal blank signal indicating a non-display period of image data.

Here, a case is shown in which a cursor is displayed in a certain horizontal scan. When the previous display cycle shown in FIG. 3 is completed and the horizontal blanking cycle shown in FIG. According to this address, the cursor pattern data read out from the video memory
(not shown in the figure) is stored in the register 3. Subsequently, the horizontal blanking cycle shown in FIG. 3 is completed, and the display cycle shown in FIG.

The image data read out from the video memory 1 according to this address is loaded into the second parallel-to-serial converter 5 according to the load clock 2 (not shown in FIG. 2), converted into bit-serial data, and then the video A video signal is created in the signal creation circuit 6. Here, according to the cursor display signal outputted by the display control section 11, the cursor pattern data stored in the register 3 is input to the first parallel-to-serial converter 4 according to the load clock 1 (not shown in FIG. 2). A cursor can be displayed by converting the data into code or bit serial data and synthesizing it in the video signal generation circuit 6.

The embodiment of cylinder 1 has been described in detail above, but in the first embodiment, the pattern data of the cursor is read out from the video memory (from the video memory) only in the horizontal blank cycle, that is, in the raster retrace cycle. .

Next, a second embodiment is shown in FIG. In the second embodiment, the number of times the car/norreno turn data is read is increased compared to the first embodiment.

In FIG. 4, the same reference numerals as in FIG. 1 are the same functional blocks.

In FIG. 4, the video memory stores two image data and cursor pattern data, and has a random access memory section (hereinafter referred to as RA) equipped with a board that can be randomly accessed.
M) 14, and a serial access memory unit (hereinafter referred to as SAM) 15 equipped with a serially accessible board.
It uses a dual-port memory that can transfer a plurality of data row by row from the RAM 14 to the SAM 15.

This is done by reading out the image data stored in the RAM 14 of the video memory 1 in a certain horizontal display cycle, and by, for example, giving an address from the display control unit 11 that specifies the image data for each horizontal display line. -Transfer line-by-line image data from RAM 14 to SAM 15,
It is read out serially from the SAM 15.

The first and second registers 3-1, 3-2.

When reading the cursor pattern data from RAM 14 of the video memory 1, R is read in the horizontal scanning cycle one scan before the horizontal scanning cycle in which the cursor is displayed.
The pattern data is transferred from the AM 14 to the first register 3-1, and is transferred from the first register 3-1 to the second register 3-2 at the beginning of the first horizontal scanning cycle.

FIG. 5 shows a sequence diagram of the second embodiment.

In FIG. 5, signals with the same names as in FIG. 3 have the same functions. Here, a case will be shown in which the cursor is displayed at a certain horizontal display cycle.

From the counter 2 to the RAM 14 of the video memory 1 in the previous horizontal scanning cycle shown in FIG.

An address for reading cursor pattern data is output, and cursor pattern data according to this address is stored in the first register 3-1 in synchronization with the write clock 1. Subsequently, at the beginning of the horizontal scanning cycle shown in FIG. 5 (■), data is transferred from the first register 3-1 to the second register 3-2 in synchronization with the write clock 2.
In the horizontal display cycle shown in , the 2-display control unit 11 outputs an address that specifies the image data for each horizontal display line, and the RAM 14 for the specified image data for each line is stored inside the video memory 1. From SAM15
The image data is transferred to the SAM 15, and the image data is serially output from the SAM 15. This serially outputted image data is transferred to a second parallel-to-serial converter 5 according to the load clock 2.
The video signal generation circuit 6 converts the signal into a video signal, and outputs a cursor display signal from the 1 display control section 11. According to the cursor display signal and the load clock 1, the first parallel-serial signal is output from the second register 3-2. The cursor pattern data is loaded into the converter 4 and converted into bit serial data. As a result, the video signal generation circuit 6
The cursor patterns are synthesized and the cursor can be displayed.

In this manner, in the second embodiment, cursor pattern data is read out during periods other than the horizontal blanking cycle during the horizontal scanning cycle. Therefore, a dual port memory is used as the video memory, and the pattern data is read out in the horizontal scanning cycle before one horizontal scanning of the cursor display. Second register 3-1.3-2
The system employs a method of delaying one horizontal scanning cycle using .

〔effect〕

As described above in detail, according to the present invention, an independent memory for storing cursor patterns is not required. Furthermore, the control circuit becomes relatively simple, and by using a portion of the video memory as a cursor pattern area, it becomes possible to realize many types of cursor patterns.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of the principle of the cursor display method of the present invention. FIG. 2 shows a first embodiment of the present invention. FIG. 3 is a sequence diagram of the first embodiment. FIG. 4 shows a second embodiment of the present invention. FIG. 5 is a sequence diagram of the second embodiment. FIG. 6 is a block diagram of a conventional cursor display method. In the drawing. 1.30 is video memory. 2 is a video memory control unit. 3.3-1.3-2 is a register. 4.5.34.35 is a parallel to serial converter. 6.36 is a video signal generation circuit. 7.37 is 1 display section. 11 is a 1 display control unit. 12.33 is a counter. 13 is a multiplexer. 14 is a random access memory (RAM). 15 is a serial access memory (SAM). 31 is a cursor memory. 32 indicates a control circuit.

Claims (1)

[Scope of Claims] A display device using a bitmap method includes: a video memory (1) that stores image data for displaying an image and pattern data regarding the shape of a cursor to be displayed on the screen; and a display section. While generating the synchronization signal of (7), generate the address of the image data or the address of the cursor pattern data to the video memory (1), and output a cursor display signal indicating the cursor display position. a video memory control unit (2), a register (3) for storing pattern data of the cursor outputted from the video memory (1), and a register (3) for storing the pattern data of the cursor stored in the register (3); a first parallel-to-serial converter (4) that converts the image data output from the video memory (1) into bit serial data according to the cursor display signal and outputs the converted data; The bit-serial data output from the second parallel-to-serial converter (5), the first parallel-to-serial converter (4), and the second parallel-to-serial converter (5) are superimposed and synthesized. , and a video signal creation circuit (6) for creating a video signal, the video memory (1)
A cursor display method characterized in that the image data and the cursor pattern data are stored together.