JPS63250690A - Cursor pattern rewrite processing 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 is a cursor pattern rewriting processing method that rewrites a cursor pattern in a cursor pattern memory while a cursor is being displayed on a display device. The memory is accessed to rewrite the cursor pattern, and when there is a conflict with an access for display, the address of the conflicting cursor pattern memory is held.

This processing method allows sufficient time to rewrite the cursor during display with a simple circuit.

[Industrial application field]

The present invention relates to a cursor pattern rewriting processing method,
In particular, the present invention relates to a cursor pattern rewriting processing method for rewriting a cursor pattern in a cursor pattern memory while a cursor is being displayed on a display device.

Various cursor patterns are used for the cursor displayed on the display depending on its purpose, and a plurality of cursor patterns to be displayed are stored in the cursor pattern memory.

However, since the storage capacity of this cursor pattern memory is limited, it may be necessary to rewrite the stored cursor pattern, and the rewritten cursor pattern may be required for the next screen display.

Therefore, it is desired to rewrite data while it is being displayed on a display device using a simple circuit.

[Conventional technology]

FIG. 4 is a diagram illustrating rewriting of a cursor pattern in a conventional example.

As shown in FIG. 4, the image display device includes a cursor control circuit 10.
, two memories, a cursor pattern memory 1 and a cursor pattern memory 2, for storing cursor patterns, and a display device 3.

When the cursor pattern in the cursor pattern memory 1 is being displayed on the display 3, a processor (not shown) writes the cursor pattern to be rewritten into the cursor pattern memory 2 via the processor bus 4.

In this way, two cursor pattern memories are prepared for reading for display and writing for rewriting.
By having different cursor pattern memories share the processing, rewriting during display is possible.

However, controlling two cursor pattern memories in this way requires a large circuit, so there are other conventional methods that use one cursor pattern memory.
FIG. 5 is a diagram illustrating the timing of this example.

In another embodiment, as shown in FIG. 5, a vertical blanking signal synchronized with a vertical synchronization signal of the display is used to set a vertical blanking period VR during a period in which no image is displayed on the display 3.

The processor sends out a cursor pattern by interrupting the start signal of the display's vertical retrace period ■R,
The cursor pattern memory is rewritten using this vertical retrace period VR.

[Problem that the invention seeks to solve]

In these conventional methods, in order to replace the currently displayed cursor, one method requires two cursor pattern memories.
In other methods, the cursor pattern is rewritten using the vertical retrace time, so depending on the cursor pattern, the rewriting time may be insufficient and rewriting may not be possible.

The present invention was created in view of these points, and provides a method for extending the period for rewriting the cursor display by sending a cursor display end signal and ensuring a sufficient period for rewriting the cursor display. The purpose is to

[Means for solving problems]

In order to achieve the above purpose, a cursor pattern memory that stores various cursor patterns, a cursor pattern memory access circuit that accesses a desired cursor pattern from the cursor pattern memory, and a control for displaying the cursor pattern on a display device are provided. and a bus control circuit that connects the cursor pattern memory access circuit and the cursor control circuit to a processor bus to exchange data.

[Effect]

In response to a cursor end signal sent by the cursor control circuit to notify the end of cursor display, the processor starts rewriting the cursor pattern through the bus control circuit and the cursor pattern memory access circuit.

When there is a conflict between reading and writing the cursor for display and rewriting, the cursor pattern memory access circuit sends out a conflict signal to interrupt, and the processor stops rewriting.

When rewriting is interrupted, the cursor pattern memory access circuit stores the interrupted cursor pattern memory address and writes the remaining cursor pattern in response to the next cursor end signal.

〔Example〕

FIG. 1 shows a block diagram of an embodiment of a cursor pattern rewriting processing method according to the present invention.

The cursor control circuit 11 detects the cursor display position on the display 3, and the cursor pattern memory access circuit 1
3 to read the cursor data.

The cursor pattern memory access circuit 13 sends the address of the designated cursor to the cursor pattern memory 14 and reads the cursor pattern data.

The read cursor pattern data is displayed at a position on the display 3 designated by the cursor control circuit 11.

When rewriting the cursor pattern stored in the cursor pattern memory 14, a processor (not shown) transfers data of the cursor pattern to be rewritten to the processor bus 4.
The data is sent to the bus control circuit 15 via the bus control circuit 15.

The cursor pattern data is output to the cursor pattern memory access circuit 13 and the cursor control circuit 11
is written into the cursor pattern memory I4 according to the instruction.

On the other hand, FIG. 2 is a diagram explaining the screen display of the display, in which the image display on the display is performed between the horizontal display period H and the vertical display period ■, and the horizontal blanking period HR during which no image is displayed and the vertical blanking period. There is a line period ■R.

The cursor (arrow in the figure) is displayed during the vertical display period during the image display period.

Generally, on a 20-inch non-interlaced CRT display, the horizontal display of one screen is 1280 dots per raster.
The vertical display is approximately 1024 rasters.

Cursors come in various shapes and sizes, for example, the cursor display period can be 32 rasters or 64 rasters.

When rewriting the cursor, enable interrupts to the processor and wait for a cursor display end signal IRQO.

The cursor control circuit 11 detects the end of cursor display and sends out a cursor display end signal IRQO.

This signal causes the cursor pattern to be rewritten from that point onwards.

FIG. 3 is a diagram explaining the timing of screen display,
As shown in the figure, the vertical blanking signal is synchronized with the vertical synchronization signal to display the vertical blanking period V.
R and the vertical display period ■ constitute one screen display cycle.

Then, the cursor display end signal I RQO generated when the cursor display period ends is sent. □ Cursor rewriting starts from the time P when it is sent, and can be rewritten until the next cursor display period starts. It's time.

If the rewriting of the cursor is not completed before the next cursor display starts, and there is a conflict between reading and writing, the cursor pattern memory access circuit 13 sends out a conflict signal IRQI to retrieve the address of the conflicting cursor pattern memory. held in its internal register.

Then, it waits for the next cursor display end signal to be generated and resumes writing the cursor pattern from the held memory address.

The cursor display end signal I RQO and the contention signal rRQ1 are both sent to the interrupt signal IR via the bus control circuit 15.
Q is sent to the processor bus 4.

〔Effect of the invention〕

As described above, according to the present invention, the storage capacity of the cursor pattern memory can be reduced, and the time required to rewrite the cursor pattern can be increased.
It is extremely useful in practical terms.

[Brief explanation of drawings]

FIG. 1 is a block diagram of the configuration of an embodiment of the cursor pattern rewriting processing method of the present invention, FIG. 2 is a diagram explaining the screen display of the display, FIG. 3 is a diagram explaining the timing of screen display, and FIG. 4 is a diagram explaining the screen display timing. FIG. 5 is a diagram for explaining cursor pattern rewriting in a conventional example, and FIG. 5 is a diagram for explaining timing in another conventional example. In the figure, reference numeral 11 indicates a power/truss control circuit; 13 indicates a cursor pattern memory access circuit; 14 indicates a cursor pattern memory; 15 indicates a bus control circuit; 3 indicates a display; 4 indicates a processor bus; IRQO indicates a cursor display end signal; Figure 3: The turn of the φ cursor pattern! Figure 4 Figure 5

Claims (1)

[Claims] A cursor pattern memory (14) that stores various cursor patterns, a cursor pattern memory access circuit (13) that accesses a required cursor pattern from the cursor pattern memory (14), and a display device (3) for the cursor pattern. a cursor control circuit (11) that controls the display of the cursor pattern memory access circuit (13) and the cursor control circuit (11), and a bus control circuit (4) that connects the cursor pattern memory access circuit (13) and the cursor control circuit (11) to a processor bus (4) to exchange data.
15), and a cursor end signal (15) sent by the cursor control circuit (11) to notify the end of cursor display.
IRQ0) allows the processor to control the bus control circuit (15).
starts rewriting the cursor pattern through the cursor pattern memory access circuit (13), and when there is a conflict between reading and rewriting the cursor pattern, the cursor pattern memory access circuit (13) sends a conflict signal to notify of the conflict. A cursor pattern rewriting processing method characterized by transmitting (IRQ1) and holding an address of a conflicting cursor pattern memory (14).