JPS58166387A - Image memory reading 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 The present invention provides a display device having a plurality of stomach images, particularly,
Reading from multiple image memories in a CI display device that performs raster display - Regarding the memory read method, it is possible to efficiently and quickly display both images based on image data retrieved from multiple image memories. It was designed to be obtained.

In general, CI with memory device? In the display device,
When a character is displayed in raster form by accessing a character stored in the address space of another memory device based on a character code stored in that memory device, which is a dot matrix representing a character pattern. In contrast, in a CRT display device having an image memory, CR is
When performing so-called raster display, which directly determines the on/off of each dot in the raster on T, that is, the brightness and darkness, it is necessary to provide a plurality of image memories and set image data read from each of the plurality of image memories. For example, in color display, these correspond to the three primary colors ReGeB. In such a combination display, it may be necessary to know what kind of image data each corresponds to in a plurality of image memories. For example, in color display, CR
When you want to know in what color one point in the raster display on T, that is, the I dot, should be displayed, you need to know the state of the image data in each image grid that constitutes one point in the raster display. I need to know. In such a case, for example, the image data for 1/1000 points in the image memory (凰MEmari) corresponding to red (2) is 1/", and the image data corresponding to the other matte (2) (blue)) is 1/". If the image data attached to that one point in both images (G Memo 9ml memory) are both @0, the tenth point will be displayed in red (2). .

In the above-mentioned case, conventionally, in order to know what kind of image data is in each image matrix for one point in the raster display, for example, the image data at a certain address is requested from 8 memories, and then, GJmo! After reading the image data separately from each image grid, such as sequentially reading out the image data at a certain address, the combination of these -image data is read out as one image data in the raster display. It was necessary to determine what kind of display a point was made according to the shiftware program.In order to determine the state of the image data in the memory, it was necessary to determine what kind of display the point was made according to the shiftware program. Data is read out separately for each display, and it is determined based on a software program what kind of display the combination of the read data produces. Therefore, in order to determine whether a point in the raster display is red or not, it is necessary to read data from the image memory three times and then make the determination in software, making the determination program complicated. In addition, there was a drawback that the determination procedure was complicated and time-consuming.

An object of the present invention is to eliminate the above-mentioned conventional drawbacks, read out image data from a plurality of image memories simultaneously, and
It is an object of the present invention to provide an image memory readout system in which only image data meeting a predetermined condition is transmitted to a data bus of an arithmetic processing unit (CPU), for example, as 111.

That is, the image memory reading method of the present invention is configured such that predetermined conditions are set and only the image data of l dots that meet the conditions are output, so that, for example, image data of @l'' can be obtained. , when reading image data from the image memory, if you issue a read command after setting the condition register according to the desired conditions, then among the image data read from multiple image memories, if the condition register matches the conditions in the condition register. The l bit is selected and the value of the l bit is transferred to the CPU side as image data in the image memory corresponding to the l dot at that time.Therefore, by the method of the present invention, the value of the l bit is transferred to the CPU side as image data in the image memory corresponding to the l dot at that time. By reading the image/data from the image memory, it is possible to easily read the image data from the image memory so that only the points that meet the desired conditions are 171.
The present invention will be described in detail below with reference to the drawings.

FIG. 1 shows an example of the configuration of an image memory readout device in the case where the method of the present invention is applied to read out image data from an image memory for three frames provided in an FIT display device. An example of the detailed configuration of the condition selection circuit is shown in FIG.

In the configuration example shown in the first diagram, 1 to 3 are image memories each having a memory capacity for l frames, DA is a condition register for specifying selection conditions, and 3 is a condition selection circuit. On the other hand, in the configuration example of the condition selection circuit shown in FIG. 1, 6 to 1 are decoders, and tNll
is a logic circuit for selecting any bit in the condition register.

In the image memory readout device having the configuration shown in the figure, first, when a data readout command is issued to the image memories 1 to 3 for three frames from, for example, a microphone processor in the display device main body, each of the two image memories The image eater in l~3 is each path D,...~D@! .

D.I. 〜Day 1D2゜〜D1 are respectively supplied to the decoders 6 to t, and the decoders 6 to t provided for each bit decode three frames of image data bit by bit. For example, in the decoder 6, ,
Out of each output bus d, . Then, by logically ANDing the output data with each bit from the ℃ condition register in the logic circuit 9, l bits of the S bits from the register are selected. Such data processing is carried out by a data bus D that uses l bits in the illustrated example.
By performing the same number of scans at the same time corresponding to the width of I, for the t-dot of image data in each pixel memory /-, 7 specified by address bus AD, "O'e@/" of image data for J frames is determined. Among the combinations, only the bit corresponding to the combination specified as 11" in the condition register is @l", and the other bits are @O', and the l-bit image data is transferred to the data bus DB. Each sb~
D, is output on top.

Next, an example of the process of reading all image memories according to the method of the present invention will be explained.
correspond to the three primary colors R, G, and l, respectively,
In the raster display, image data is requested by setting only the dots displayed in red (2) to 1/' and the other dots to IIo''.

In that case, in order to select only the dots for which the combination of dots in the J frame image data becomes @1vOtO, enter @0100000 in the condition register.
By setting 0 ”, it takes @/*0*0”
It is possible to read combinations of

Similarly, when reading out only the dots displayed in either red (6) or yellow (R+G), the combination of each dot is "/eO*01 or"
/*/eO", so @01010000" is set for the condition register.

As is clear from the above description, according to the present invention, image data can be read out in a similar manner not only in the illustrated color display device but also in a monochrome display device having a plurality of image memories. 0～
In a monochrome display device having an image memory for J, it is possible to read the image data of only the dots displayed in either frame 0 or frame l, or to read the image data of only the dots displayed in frame l but not in frame 7. You can easily read out image data of only dots that are not displayed by simply setting the condition register appropriately. Four registers can be set so that image data can be output.For example, image data can be read in the form of exclusive OR of image data of frame O and 7 frames I by setting the row condition register @0. It will be set to //DO/10'.

In the above example, the condition register has S bits, but the number of bits in the condition register does not have to be limited to this.

[Brief explanation of the drawing]

FIG. 7 is a block diagram showing an example of the configuration of an image memory succession device according to the present invention, and FIG. 1 is a block diagram showing an example of the detailed configuration of the condition selection circuit.・-Image mesori, ◆・・・Condition register, 3
...condition selection circuit, 1~l...decoder, t~
l/...logic circuit, AB...address bus, DB...data bus. Patent applicant Canon Co., Ltd.

Claims (1)

[Claims] When requesting from a plurality of image memories in a display device having a plurality of image memories, Wt from each of the plurality of image memories is calculated under the same necessary conditions.
Image memory successive storage method that takes advantage of the fact that mL is performed at the same time and images are displayed.