JPS6139675B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a display control device, and specifically to a peripheral device for a display monitor that does not require a decoder for input data.

Generally, a control device for a CRT display is constructed as shown in FIG.

That is, when display data is input as input data, that data is written into the refresh memory RM1 corresponding to the specified line/column address. The display is the output of the coincidence detection circuit EOR4 between the line/column address register L/CAR2 and the display counter DC3 for generating vertical/horizontal/video signals, the display data from the refresh memory RM1, and the display counter DC3. Vertical and
It generated a horizontal video signal.

If data unrelated to the display data, for example data that only instructs cursor movement, is input, it is decoded by the decoder DEC5 and the line/
The contents of column address register L/CAR2 were changed.

Although not included in the above description, 6 is a character generator CG, a vertical/horizontal/video signal generator SG, and the above-mentioned refresh memory
It is used to generate vertical synchronization signals, horizontal synchronization signals, video signals, etc. for the CRT monitor 7 using signals from the RM1, the coincidence detection circuit EOR4, and the display counter DC3.

However, as the types of data unrelated to the display data increase, the decoder DEC
5 has a large capacity.

Therefore, in today's world where special symbols and screen operation functions are increasing and devices are becoming more compact, the above-mentioned drawbacks cannot be ignored.

The present invention was made in view of the above-mentioned drawbacks, and by making the registers used for character display and control other than character display independent of the CRT, the capacity of the decoder can be reduced, and the capacity can be used for control other than character display. The purpose of the present invention is to provide a display control device that provides a display control device.

Hereinafter, the display control device of the present invention will be explained in detail using FIG. 2 and subsequent figures.

FIG. 2 shows an embodiment of the storage control device according to the present invention. In the figure, 11 and 12 are CRTs, respectively.
These are input data registers IDR and IDR used for character display and control other than character display. or,
13 is a refresh memory RM for refreshing the data displayed on the CRT monitor screen; 1
4 is a line/column address register L/C which has a count function to provide the display position of the CRT monitor, the write/read address of the refresh memory RM13, and the display position of the cursor.
AR, 15 is line/column address register L/C to display the cursor on the CRT monitor.
A coincidence detection circuit EOR compares AR, 14 with a display counter DC to be described later, 16 a display counter DC for creating a raster, 17
are various generators CG/SG (Character generator CG, vertical/horizontal/video signal generator SG) and the refresh memory RM1.
3. The coincidence detection circuit EOR15 and display counter DC16 generate vertical synchronization signals, horizontal synchronization signals, video signals, etc. for the CRT monitor.

Also, 18 is a CRT monitor that displays the screen, 19
is an input data signal line from the outside to the CRT device, 20 is a write signal line of input data register IDR11 that receives data for displaying the CRT screen, and 21 is an input data register IDR that receives data not directly related to the CRT screen.
11 to the refresh memory RM13, and a write signal line 23 to the input data register IDR12, when, for example, data instructing cursor movement is input, the line/column address register L/23 is connected to the line/column address register L/column address register L/23 depending on its contents. C
A control signal line 24 is used to update the contents of the AR14, a control signal line 24 is used when data instructing an operation other than cursor movement is input to the input data register IDRR, and a line 25 is a line for writing/writing to the refresh memory RM13. A signal line 26 indicating a read address is a clock signal line for the line/column address register L/CAR 14 and display counter DC 16.
27 is a read data signal line of the refresh memory RM13, 28 is a cursor address signal line for indicating the position of the cursor display, and 29 is a line when the value of the display counter DC16 matches the value of the line/column address register L/CAR14. Video signal generator CG/SG1
7, control signal lines 30 and 31 are control signal lines for generating vertical synchronization, horizontal synchronization and video signals, and 32 is a vertical synchronization and horizontal synchronization video signal line for the CRT monitor 18.

The operation will be explained in detail below using the timing chart shown in FIG. In addition, in FIG. 3, the signal lines 19, which are directly related to the present invention,
Only the timings of 20, 21, 22, 23, and 24 are described, and the operations related to the screen display of the CRT monitor are well known and are not directly related to the present invention, so they will be omitted.

First, data to be displayed on the screen is sent from the outside via line 19.

Furthermore, upon arrival of the write signal 20, the input data register IDR11 sets data and outputs it to the signal line 22.

Similarly, if the data is unrelated to the display on the screen, such as moving the cursor one character, the data is on line 19.
When the write signal of line 21, which is different from line 20, is input, a control signal 23 is generated to move the cursor by one character. (For example, operation instruction signal) 23 moves the cursor to 1
This is a control signal to move by a character, but line 22
There is no need to limit the data input to line 22, and any data can be used as long as it has a purpose below line 22.

24 shows the operation.

As described above, according to the present invention, there is no need for a decoder for input data, the amount of hardware is reduced, and control becomes more efficient. Therefore, in today's world where display devices are becoming more compact and the number of special symbols and screen operation functions are increasing, the present invention becomes an effective means.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a conventional display control device, FIG. 2 is an embodiment of the display control device according to the present invention, and FIG. 3 is a timing chart for explaining its operation. 11・12...Input data register (IDR),
13... Refresh memory (RM), 14...
Line/column address register (R/CAR),
15... Match detection circuit (EOR), 16... Display counter (DC), 17... Generator (CG/SG), 18... CRT.

Claims (1)

[Claims] 1 A first register that sets the data according to the arrival of data to be displayed on the screen from the outside and a write signal thereof, and a first register that sets the data according to the arrival of data unrelated to the screen display and a write signal thereof. 2 data registers, and the second data register.
1. A display control device comprising a display monitor and a line/column address register for providing a display position of a cursor based on the output of a data register.