CN102184070A - Method and device for displaying cursor of hardware support - Google Patents

Abstract

The invention discloses a method and device for displaying a hardware support cursor. At least one background image channel DMA (Direct Memory Access) and data cache, one cursor AND bitmap DMA channel and data cache and one cursor image XOR (Exclusive OR) bitmap DMA channel and data cache are adopted in the method and the device, format conversion is carried out by using a color palette according to a bitmap format of the cursor, and finally, the cursor and a background image are synthesized in an image synthesizing unit by using a display principle of the cursor, and the synthesized image is output through a display interface.

Description

Method and device that a kind of hardware supported cursor shows

Technical field:

The present invention relates to the chip design field, more particularly, relate to method and device that a kind of hardware supported cursor shows.

Background technology:

Cursor is operation the most used in the operating system, the demonstration of cursor generally has operating system directly that cursor and background image is synthetic, promptly finish this part synthetic operation of image by processor, this can involve a large amount of calculating and internal memory operation.

In general, the cursor pattern all is made up of two independent bitmaps.If this icon is the shielding background colour, so, first bitmap is made up of black background (relevant colour bits are 0 entirely) and color map pattern, and this bitmap will show by xor operation (XOR) with current screen and combine, so be called the XOR bitmap; Second bitmap is made up of with black icon pattern (relevant colour bits are 0 entirely) white background (relevant colour bits are 1 entirely), and this bitmap will show by combining with operation (AND), so be called the AND bitmap with current screen.Therefore, the demonstration of icon is finished by two steps:

1, current background and AND bitmap combine by the AND operation;

2, current background and XOR bitmap combine by xor operation.

1 will keep former numerical value with the result of any numerical value AND operation, 0 with the result of any numerical value AND operation then be 0, therefore in step 1, the white in the AND bitmap (1) is shielded by original color through AND operation back with screen display, and black (0) then shields original color.After step 1 finishes, will stay the icon pattern of next black on the screen.In step 2 subsequently and since 0 with the result of any numerical value XOR all will be former numerical value, therefore, the XOR bitmap shows through behind the xor operation that with screen 0 the black part in bitmap and the screen all will be shielded by each self-corresponding chrominance section.After step 2 finished, an icon pattern in irregular shape had just appeared on the screen.

Therefore for the move operation of a cursor, as shown in Figure 1, cursor from coordinate (A, B) move to coordinate (C, D), need finish by step once:

(A, B) position removes from coordinate with cursor glyph.

1, background image is filled back origin coordinates (A, B) former cursor glyph affiliated area.

2, will be from origin coordinates from (C, regional background image D) and the AND bitmap operation of cursor.

3, again with the XOR bitmap operation of cursor, but as its image need palette, also need are operated after with color conversion by palette again.

4, the operating result data being filled can display buffer.

5, display unit reads synthetic good image and shows from internal memory.

From above-mentioned steps as can be seen, once the light operation of moving all has bigger load to the visit of internal memory and the computing of processor.Therefore we find in embedded OS, send out puckery through the mobile meeting of regular meeting's discovery cursor when moving cursor, and system response also can be slack-off.

Based on hardware cursor display packing of the present invention, can be from reducing access times largely to internal memory, and discharge the occupation rate of processor.

By method of the present invention, when moving cursor, processor only need dispose the position of cursor, and the demonstration that display module just can be finished image merges, and subsequent process no longer needs the participation of processor.

Summary of the invention:

The method that the object of the present invention is to provide the support hardware cursor to show.The concrete technical scheme that realizes the object of the invention is as follows:

The performing step of the display control unit that a kind of hardware supported cursor shows comprises:

First step, processor dispose relevant controlled variable according to demand, as parameters such as the start address of the start address of the start address of background image, cursor XOR bitmap, AND bitmap and picture format, sizes.

Second step, background image passage DMA reads background image data according to the start address of background image data from internal memory, write data buffering.

Third step, AND bitmap passage DMA reads the AND data bitmap from internal memory, write data buffering.

The 4th step, XOR bitmap passage DMA reads the XOR data bitmap from internal memory, write data buffering.

The 5th step, image synthesis unit are from background image passage reads pixel data, and elder generation and AND bitmap channel data are done and operated.

The 6th step, the image synthesis unit is debugged plate from XOR bitmap passage reading of data according to color form such as need, earlier by palette color conversion is become required display format, again and operating result before do xor operation, obtain composograph.

The 7th step, the pixel data of finishing after synthesizing is exported by display interface.

It is a kind of for realizing the device of said method that another object of the present invention is to provide.

The concrete scheme that realizes apparatus of the present invention purpose is as follows:

The display control unit that a kind of hardware supported cursor shows is characterized in that comprising with lower module:

At least one background image passage, each background image passage have a DMA and input data buffering;

The data DMA passage of an XOR bitmap and an input data buffering and an associated palette (existing) with register form;

The data DMA passage of an AND bitmap and input data buffering;

Synthetic the finishing synthesizing of image of image is exported from the display interface interface.

The described background image of said apparatus can be for a plurality of, and the data DMA passage of corresponding background image, input data buffering all correspond to a plurality of.After synthesizing, synthesize with cursor more a plurality of background images.

Beneficial effect of the present invention:

The display control unit of hardware supported cursor provided by the invention is synthetic by finish image in display device, so do not revise the data of background image in the internal memory display buffer at the moving process of cursor.

The display control unit of hardware supported cursor provided by the invention only needs processor configuration reference position by the mode at DMA, just can finish the demonstration of cursor.The palette of the display control unit of hardware supported cursor provided by the invention in addition realizes with the form of register, when the need palette directly by the realization color conversion of tabling look-up.Method provided by the invention has reduced the calculating and the data access process of processor, also helps reducing power consumption.

Method provided by the invention can be used with the laminated device that becomes of other figure, so background image can be the multi-layer image combination.

Description of drawings:

Further specify the present invention below in conjunction with the drawings and specific embodiments.

Fig. 1 cursor moves the demonstration example.

Fig. 2 is based on the structured flowchart of the support hardware cursor display device of the present invention's realization

The display process process flow diagram of Fig. 3 cursor

Embodiment:

Set forth the present invention with the mobile example that is shown as of the cursor of single-layer background image below.

As shown in Figure 1, the previous moment cursor be in coordinate (A, B), next need constantly with cursor move to origin coordinates (A, B).Concrete implementation procedure is as follows:

1, suppose that boxed area is the viewing area, background image passage DMA writes data buffering according to start address, picture size reading of data from internal memory of processor configuration.The image synthesis unit cushions reading of data from background image data, and begins to show by pixel line by line from (0,0) position.Simultaneously AND bitmap passage and XOR bitmap with DMA also according to start address, picture size reading of data from internal memory of the configuration of processor, and write data buffering and when data buffering is full, suspend data access.

2, (A, in the time of B), the image synthesis unit is reading of data from background image data buffering and AND data bitmap buffering, and carries out the AND operation to arrive coordinate at display position.After this operation, can in background image, sketch the contours of the profile of cursor.

3, in reading of data from the XOR data buffering, judge that its data layout is very coloured silk or palette form,, with the debugging plate data are sent into the debugging plate and found out corresponding color data as needs.

4, the pixel data that obtains in the data that obtain and the step 2 is carried out xor operation, cursor is implemented in the purpose on the background image like this.

5, the pixel after synthetic shows by display interface

6, when moving coordinate, the coordinate position control register that processor only need be initial with cursor from (A, B) be modified as (C, D).The image synthesis unit naturally can with cursor from following from (A, B).

Therefore when cursor moves, can accomplish quick response based on device of the invention process.

The embodiment that above-mentioned hardware supported cursor shows is a kind of typical embodiment of the method for the invention.For those skilled in the art, on the basis of above-mentioned implementation method, change a little and also can realize target of the present invention, but this obviously also should be in claims scope of the present invention.

Claims (5)

1. the method that shows of a hardware supported cursor is characterized in that may further comprise the steps:

First step, processor dispose relevant controlled variable according to demand, as parameters such as the start address of the start address of the start address of background image, cursor XOR bitmap, AND bitmap and picture format, sizes.

Second step, background image passage DMA reads background image data according to the start address of background image data from internal memory, write data buffering.

Third step, AND bitmap passage DMA reads the AND data bitmap from internal memory, write data buffering.

The 4th step, XOR bitmap passage DMA reads the XOR data bitmap from internal memory, write data buffering.

The 5th step, image synthesis unit are from background image passage reads pixel data, and elder generation and AND bitmap channel data are done and operated.

The 6th step, the image synthesis unit is debugged plate from XOR bitmap passage reading of data according to color form such as need, earlier by palette color conversion is become required display format, again and operating result before do xor operation, obtain composograph.

The 7th step, the pixel data of finishing after synthesizing is exported by display interface.

2. the method that a kind of hardware supported cursor as claimed in claim 1 shows is characterized in that:

In the described first step, the configuration of processor is the application according to system, the demonstration demand, and the user operates etc. that operation is configured.

3. the method that a kind of hardware supported cursor as claimed in claim 1 shows is characterized in that:

Described second and third, the DMA in four steps only does data transmission and uses, can be according to the resource requirement of different system, performance requirement is realized different mode of operations.

4. the method that a kind of hardware supported cursor as claimed in claim 1 shows is characterized in that:

In described the 6th step, can judge whether to call palette, when its data layout is never called palette when very color, when its data layout is according to the data layout that reads from the XOR data buffer.During the palette form, then data are imported palette and searched corresponding color data.

5. the display control unit that shows of a hardware supported cursor is characterized in that comprising with lower module:

At least one background image passage, each background image passage have a DMA and input data buffering;

The data DMA passage of an XOR bitmap and an input data buffering and an associated palette (existing) with register form;

The data DMA passage of an AND bitmap and input data buffering;

Synthetic the finishing synthesizing of image of image is exported from the display interface interface.

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