JPS58129473A - Memory control 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 (1) Technical field of the invention This invention relates to a control method for a memory that stores video information of an apparatus.

(2) Background of the technology When displaying an image on a CRT or the like, if the screen is expressed by binary information of, for example, 1024 dots in the vertical and horizontal directions, the screen is stored in a memory with a bit number of +024 x 1024 corresponding to the number of dots. 1# in the same order as scanning! It is common practice to store information.

On the other hand, when the image to be displayed is a specific number such as numbers such as 0 to 9 or characters such as A to 2, the pattern of the character, etc. is stored in the ROM, and the 1I11 screen is divided into one pair of dots, for example, s2 dots. Divide into a matrix (52 x 52) divided into 52 x 52 dots, create a code table corresponding to each cell, and set the ROM address of the necessary character, etc. at the position corresponding to the cell on the code table. Measures are taken to memorize it. By doing this, it is only necessary to have a ROM with a limited number of bits necessary for storing characters, etc., and a memory with a small number of bits necessary for the code table, and the above-mentioned 1024 x 1
It does not require a large memory of 0.24 bits, and it is extremely easy to change colors, scroll, insert or delete characters, etc. by simply rewriting the code table.

However, when the image to be displayed is a figure or the like and is not a specific object such as a character, it is not possible to store it in a ROM and omit the memory, so the above-mentioned character display method was not adopted. The present invention relates to a memory control method that takes advantage of the advantages of the character display method even when processing unspecified images (hereinafter referred to as images) such as graphics.

(3) Problems with the prior art In the conventional memory control method 1 when processing images, a bitmap-like two-dimensional memory corresponding to the screen ′ as shown in FIG. 1(a) is assumed, and the screen Consecutive addresses are allocated in the order of scanning. In an actual memory, as shown in Figure 11 (Hiro, No. 11), -dimensionally consecutive addresses are allocated in the scanning order. In this case, it would be extremely inconvenient to divide the screen into a plurality of cells and perform processing on a cell-by-cell basis, as in the character display method. That is, addresses 1 and 8 in FIG. 1(a) are vertically adjacent to each other on the screen, but in actual memory addresses they are not consecutive as shown in FIG. 1(b). Therefore, in order to retrieve the image data of any part on the screen, address calculation is required, which is cumbersome to handle.
The drawback was that it was time consuming.

(4) Purpose of the Invention The purpose of the present invention is to make it possible to easily access data in any part of the screen cell by cell when processing image data, and to take advantage of the advantages of the character display method described above. The purpose of the present invention is to provide a memory control method.

(5) Structure of the Invention The structure of the present invention is as described in the claims, and in addition to logical addresses according to the scanning order in the memory that stores video information, consecutive logical addresses within a cell are This is a memory control system in which an address is assigned and a decoder is provided so that the memory can be accessed using any of the above logical addresses.

(6) Embodiment of the Invention The entire screen displayed with 1024 dots vertically x 1024 dots horizontally is divided into 52 x 52 cells, and each cell is displayed with 52 dots vertically x 52 dots horizontally. Assuming a bitmap-like two-dimensional memory corresponding to a color screen, the memory consisting of 16 bits per address is arranged in 2 rows horizontally and 52 columns vertically to form one cell, as shown in Figure 21.

As shown in Figure 2(b) K, there are 1 to 6 cells in the cell.
Assigning consecutive logical addresses up to 4 addresses (hereinafter referred to as cell mode addresses). In an actual memory, cell mode addresses are assigned one-dimensionally repeated addresses as shown in FIG. 2(e). At the same time, cough memory
As shown in FIG. 5, consecutive logical addresses (hereinafter referred to as scan mode addresses) corresponding to the order of nine scans are assigned. In this example, the scan mode addresses are not consecutive in memory, but can be treated as logically consecutive in the program. This embodiment is constructed as shown in FIG. 4 so that the memory can be accessed in either of the two modes described above. Figure 4: People use cell mode addresses as addresses in the physical order of memory (
(hereinafter referred to as physical address), a decoder that converts
C is a decoder that converts a scan mode address into a physical address, C is a rounding multiplexer that selects one of the two decoders based on a command from the CPU, and D is a memory. No matter which mode of address signal is input from address bus E, it is converted into a physical address of memory D by decoder A or B, and memory D is accessed according to the selection of the multiplexer. Depending on the correspondence between the logical address and the physical address, for example, when the physical address and the scan mode address match, the decoder B is not necessarily required.

In this way, when cell mode is selected, the second
Consecutive addresses within a specific cell shown in FIG. 1(b) are accessed, and when scan mode is selected, consecutive addresses are accessed in accordance with the scanning order as shown in FIG. 1(a).

(7) Effects of the Invention As described above, the present invention allows memory control in the normal scan mode and memory control in the cell mode to be used arbitrarily, so that complex address calculations are performed on image information input in the scan mode. Processing such as dividing or moving each cell can be done extremely easily without any trouble. As with the character display method described above, if a code table is provided, it becomes possible to move, partially replace, scroll, etc. the figures on the screen by simply changing the code table, and the l&field speed is extremely high. , is abbreviated.

Also, if you make the all-white area where no figure exists represented by one specific cell, and repeatedly specify that specific cell in the code table for the all-white area on the screen,
The memory capacity can be reduced to a large number, and image information can be handled while taking advantage of the characteristics of the character display method.

[Brief explanation of the drawing]

FIGS. 1(a) and 1(b) are illustrations of a conventional memory for storing image information, and FIG. ) is the cell mode address of the embodiment of the present invention! 51! Mingzu, No. 5
This figure shows the correspondence between the scan mode address, the cell mode address, and the physical address of the memory, and FIG. 4 is a diagram showing the configuration of an embodiment of the present invention. Figure 1 (a) (b) 2nd
Figure (lr) Figure 3 Figure 4

Claims (1)

[Claims] In a memory for storing video information of a display device that displays images in a scanning manner, the memory has a logical address according to the scanning order, and the memory is divided into a plurality of cells and consecutive logical addresses within the cell are stored. and a decoder that converts both or one of the two logical addresses into a physical address of the memory, making it possible to access the memory using either of the two logical addresses. Memory control method