JPS62147482A - Cursor controller - 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 Field of the Invention The present invention relates to a cursor control device used in an image display device having a cursor display function.

BACKGROUND OF THE INVENTION Conventional cursor control devices perform cursor display by transferring a cursor pattern to a frame memory that stores image data to be displayed on a C display screen (MN).
E3365 specifications (Matsushita Electric Industrial Co., Ltd.)), or it is equipped with a frame memory and an overlay memory that spans the entire screen, and the cursor pattern is transferred to the overlay memory, and when displaying, the data in the frame memory is transferred to the overlay memory. This was done by superimposing data (for example, "Image Apply Processor Program 7f
Mani x Full” (I P8500 5ERII!: SIM
-AGE ARRAY PROCI! 5SORPR
O(,AMMINGMANUAL”)).

In addition, a CRT controller is provided in the display control section that controls the frame memory, and a cursor display signal is output from the CRT controller, and the cursor pattern is read out during the output period of the display signal and superimposed on the image data from the frame memory. was moving (e.g. C
RT controller 5 HD46505S! - Zers Manual).

Problems to be Solved by the Invention However, the above configurations each have the following problems.

The method of transferring the first cursor pattern to the frame memory requires processing such as transferring the cursor pattern dot by dot to the frame memory and rewriting the image memory each time the cursor is moved, and also requires a multi-tone image processing device. In this case, the configuration of the image memory increases by the number of gradation bits, which requires more processing, and requires a circuit to transfer the cursor pattern at high speed.

Also, the method of transferring the second cursor pattern to the overlay memory is to write the cursor pattern to the overlay memory, so compared to the above method, the cursor pattern can only be transferred to the overlay memory even if it is a multi-tone image processing device. However, in order to transfer the pattern dot by dot to the overlay memory at high speed as the cursor moves, a secondary circuit is essential, and a memory that covers the entire screen is required.

Furthermore, the method of reading the cursor pattern under the control of the CRT controller of the third display control section uses the signal of the CRT controller of the display control section.
Even if the T-controller had an offset raster function, this function could not be utilized, and a separate circuit was required to smoothly scroll the cursor in the vertical direction.

In order to solve the above problems, the present invention takes advantage of the functions of CRT controllers that are available at low cost, and provides a cursor control section independent of the display control section, thereby providing a cursor with a simple configuration and expandability. A control device is provided.

Means for Solving the Problems The present invention provides an image display device having means for controlling the display of a cursor, the means for controlling the display of the cursor comprising a memory for storing a pattern of the cursor, and a memory for storing a pattern of the cursor; and a control unit for displaying a cursor;
The control unit includes external synchronization means, means for generating an address for reading a cursor pattern, and means for controlling the cursor pattern on a display screen dot by dot, It is configured to display a cursor by synchronizing with the display.

Effect The present invention has the above-described configuration, and by providing the cursor control section independently from the display control section except for synchronizing it with the synchronization signal from the display control section, the cursor control section can be operated regardless of the size of the display screen. First, it is sufficient to have a pattern memory with the size of the cursor pattern, and since there is no need to transfer the cursor pattern to an image memory or the like, a circuit for this purpose is unnecessary. Furthermore, by using a CRT controller having an external synchronization function, an offset address function, and an offset raster function in this cursor control section, the cursor can be easily displayed dot by dot on the display screen by taking advantage of these functions.

Embodiment FIG. 1 shows a block diagram of a cursor control device in an embodiment of the present invention. In FIG. 1, 1 is the main control section of this device which transfers image data to the frame memory and controls the display control section, 2 is a display control section which controls the frame memory etc. to display images, and 3 is a main control section of the apparatus. A frame memory section stores image data displayed on the display screen; 4 is a cursor control section that controls display of the cursor; 5 is image data read from the frame memory section 3 and a cursor output from the cursor control section 4; 6 is a CRT that monitors the image, 7 is the main control unit (1 color each unit)
, , a system address bus, and 8 a system data bus.

In the cursor control unit 4, 41 is a CRT controller (for example, a Fujitsu MB8932
42 is a cursor pattern memory section for storing cursor patterns; 43 is a decoder circuit that decodes the character address of the id CRT controller 41 to determine the cursor display timing; 44 is a decoder circuit that stores cursor pattern data read from the cursor pattern memory section 42; ,
This is a shift register unit that controls horizontal shifts in units of characters or less.

The operation of the cursor control device of this embodiment configured as described above will be described below.

First, change the screen format of the CRT controller 41 of the cursor control unit 4 to mX the number of characters displayed on the screen as shown in Figure 2.
The number of horizontally displayed characters is set to m, the number of vertically displayed characters is set to n, and the character block is set to be a dot x b line. This is C
Main control unit 1 provides clocks to the RT controller 41
It is determined by the data written to the register of the CRT controller 41. At this time, the size of the cursor pattern is changed for each character block (a dot x b line).

Now, when the display control unit 2 gives a vertical synchronization signal to the CRT controller 41 to establish synchronization, the CRT controller 41 synchronizes with the screen display and outputs a block address with the display screen as an mxn block to the decoder circuit 43. Then, the raster addresses for b lives are output to the cursor pattern memory section 42.

Assuming that the cursor pattern memory section 42 stores an axb dot pattern, at the block address selected by the decoder circuit 43, the raster address given to the cursor pattern memory section becomes valid and the cursor pattern memory section is accessed. Then, the a-dot cursor pattern data is read out for the -raster address. The read cursor pattern data is shifted by b dots or less in the shift register section 44 set by the main control section 1, and is outputted from the cursor control section 4 as cursor data.

On the other hand, the display control section 2 is controlled by the main control section 1 and accesses the frame memory section 3. As a result, the image data read from the frame memory section 3 is combined with the cursor data in the signal synthesis section 6 and output to the CBr 4, so that a cursor is displayed on the screen.

The cursor can be moved by making use of the functions of the CRT controller, and by offsetting the block address, it is possible to scroll for each block (aXb dot), and by offsetting the raster address, it is possible to scroll for each raster.

For dot-by-dot scrolling in the horizontal direction, the main control section 1 controls the shift register section 44, and the cursor pattern data can be shifted by seven dots.

As described above, according to this embodiment, the cursor control section 4 of the image display device that displays the cursor is provided independently of the display control section 2, and the cursor control section 4 is provided with an external synchronization function and an offset function. By providing a CRT controller 41 having an address function and an offset raster function, the cursor on the screen can be moved up and down one dot at a time using a memory of the size of the cursor pattern and a simple shift register circuit. In addition, from the main control unit 1
By rewriting the register of the controller 41,
Since the screen format can be changed and the only external control is a synchronization signal, changes in screen size can be easily accommodated without changing circuits or the like.

Furthermore, by making the decoder circuit 43 capable of selecting a plurality of block addresses, - character block (a
A cursor whose size is an integral multiple of the Xb dot) can also be displayed.

Note that the decoder circuit 43 has a register circuit that can be rewritten by the main control unit 1, and when an address set in the register is input, the decoder circuit 43 outputs the cursor pattern memory unit 42.
It may be something that allows access to. However, the structure of the frame memory section 3 may be one that stores binary image data or one that stores multi-value image data.As described in detail, according to the present invention, the following The practical effects are very large.

(1) By independently providing a CRT controller that can be provided at low cost in the cursor control section, the cursor can be displayed dot by dot with a simple circuit configuration.

(b) Since the cursor display method is not transferred to the overlay memory, the memory configuration only requires the shape of the cursor pattern, and the cursor can be displayed efficiently.

(The screen format can be easily changed by rewriting the registers of the 31CRT controller, and since the only external control is an external synchronization signal, it is easy to respond to changes in screen size, making it a highly expandable cursor control device. ing.

(4) Even a large cursor display can be handled with the same processing by changing the screen format, so the moving speed of the cursor on the screen is not related to the size of the cursor pattern.

(5) The same cursor control unit can be used regardless of whether the image is displayed as a binary image or a multivalued image.

[Brief explanation of drawings]

FIG. 1 is a block diagram of a cursor control device according to an embodiment of the present invention, and FIG. 2 is a screen format diagram for controlling the cursor of the same device. 1... Main control section, 2... Display control section,
3... Frame memory unit, 4... Cursor control unit, 5... Signal synthesis unit, 6...
・CRT, 7...System address bus, 8.
...System data bus, 41...CR
T controller, 42... Cursor pattern memory section, 43... Decoder circuit, 44...
...Shift register section. Name of agent: Patent attorney Toshio Nakao and 1 other person Atsushi 1
Figure 2 R dot

Claims (2)

[Claims] (1) The image display device has a cursor control means for controlling the display of a cursor, and the cursor control means includes a memory that stores a pattern of the cursor;
and a control unit for displaying the cursor, and the control unit controls external synchronization means, means for generating an address for reading the cursor pattern, and the cursor pattern dot by dot on the display screen. A cursor control device comprising means for synchronizing the image display of the image display device. (2) A control unit includes a CRT controller having an external synchronization function, an offset address function, and an offset raster function, and shifts a cursor pattern read out in character units of the CRT controller in the horizontal direction on the display in units of characters or less. 2. A cursor control device according to claim 1, comprising a shift register section to control the cursor control device.