JPS645312B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Technical Field of the Invention The present invention relates to a method of displaying data recorded in a memory of a display device on a display screen.

(b) Background of the Technology In display devices with screen memory, the display area of the memory is fixed on the display screen, and data stored in a certain location in the memory cannot be displayed at any location on the display screen. requires a complicated procedure, and there is a desire for a display method that can be displayed at any position using simple means.

(c) Prior art and problems The data in the memory of a conventional display device is
The location where the data is displayed on the display screen is determined by the location in the memory where the data is recorded. That is, data recorded at a memory location, ie, an address, displayed at the center of the display screen is always displayed at the center of the display screen, and is not displayed at other locations. Therefore, if you want to display the data in another position, you have to move the data within the memory display area or link the row data. The former has a slow display speed, and the latter has the disadvantage that a part of the data recording area is rewritten.

(d) Object of the Invention An object of the present invention is to provide a display device capable of displaying data in a memory at an arbitrary position without making the memory and the display screen correspond to each other in order to eliminate the above-mentioned drawbacks.

(e) Structure of the Invention The structure of the present invention includes a plurality of display tables each specifying an address for reading display data from an arbitrary position in a display data expansion area of a memory, and an address for selecting the plurality of display tables. By providing a display table register to be set and setting the address of the desired display table in the display table register in advance, data in the memory can be read from the address specified by the display table selected by the set address. It is designed to be read out and displayed. Therefore, by simply rewriting the register that specifies the address of the display table, it is possible to quickly move the display area on a multi-screen (displaying data for multiple screens), vertical scrolling (displaying by sequentially moving each line), and horizontal scrolling ( This allows the rows to be displayed by sequentially moving them horizontally.

(f) Embodiment of the Invention FIG. 1 is a block diagram of a circuit showing an embodiment of the invention. A memory 2 and a display table register 3 are connected in parallel to the bus 9 of the microcomputer MPU1 and are controlled by the MPU1. Memory 2 is
It consists of a work area used by the MPU 1, a screen memory where data to be displayed on the screen is stored, and an area where the display table shown in FIG. 2 is stored.
The display table is as shown in Figure 2.
When configuring a line, the address on the screen memory where the first character to be displayed on each line from the first line to the nth line is stored is specified.

The display table register 3 stores the start address of the display table whose display is to be started by a program. In response to a display start command from the MPU 1, the display table register 3 transfers the start address of the display table to the display table counter 4, and displays the display table in the memory 2 on the first line of the display screen at the address specified by the display table counter 4. The start address of the line is set in character counter 5. Data for one line starting from the first character of the specified line in the memory 2 according to the address indicated by the character counter 5 is stored in the line buffer 6, and converted into a character pattern signal by the character generator 7.
The parallel signal is converted into a serial signal by the parallel/serial converter 8 and becomes a video signal. Display table counter 4
adds 1 to the address, sets the display start address of the next line in the character counter 5, displays all the tables for the number of lines to be displayed on the full screen, and then returns to the initial value. Therefore, if you create various display tables shown in Figure 2, you can use the display table register 3 by program.
You can switch screens just by rewriting .

(g) Effects of the Invention As explained above, in the present invention, by creating various display tables in the memory, by changing the display table register, data in the memory can be freely displayed without changing as in the prior art. Furthermore, since display lines and characters can be moved simply by changing the line start address in the display table, vertical and horizontal scrolling can be achieved at high speed. Furthermore, since the display can be moved anywhere in memory at high speed, it is easy to search for data in memory, and since the data columns in memory and display columns do not necessarily correspond, it is easier to insert data,
There is also the effect that the deletion can be displayed as if it were inserted into and deleted from the memory.

[Brief explanation of drawings]

FIG. 1 is a block diagram of a circuit showing one embodiment of the present invention, and FIG. 2 is a diagram showing an example of a display table. 1 is a microcomputer, 2 is a memory, 3
is a display table register, 4 is a display table counter, 5 is a character counter, 6 is a line buffer,
7 is a character generator, and 8 is a parallel/direct converter.

Claims (1)

[Scope of Claims] 1. In a display device that reads display data from a screen memory that stores data to be displayed and displays the data on a display screen, each address for reading the display data from an arbitrary position on the screen memory is provided. This can be achieved by providing a plurality of display tables to be specified and an address setting means in which an address for selecting the plurality of display tables is set, and setting the address of the desired display table in the address setting means in advance. A display device characterized in that display data in a screen memory is read from an address specified by a display table selected by a set address and displayed on a display screen.