JPS5831591B2 - Pattern display method at arbitrary position - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for displaying patterns at arbitrary positions, and in particular,
The present invention relates to a pattern display method in which characters can be displayed at any position beyond the display range allocated for displaying the characters.

When displaying kanji characters, the 1024×1024 dots that make up the CRT screen are appropriately illuminated to display characters, lines, and the like.

Now, the 1024x1024 dots above correspond to the internal screen memory (refresh memory), and 3 of them correspond to the internal screen memory (refresh memory).
One character is made up of 2x32 dots.

However, when displaying 32 characters in one line, the character delimiters and memory delimiters match.

The pattern from the character generator can be easily written into the refresh memory by specifying the address in units of words (32 bits).

That is, it is easy to display characters in a fixed format in a predetermined area.

Incidentally, there are cases where it is desired to display kanji characters in a fixed format in a flexible position, but such a request cannot be realized with the conventional method, ie, the method of writing data from CG directly into the refresh memory.

In view of the above, it is an object of the present invention to provide a display method that can display characters at any position. After that, in a display device that reads and displays the pattern, before writing the pattern to the screen memory, input the pattern to an n-to-one minute (n≧2) shift register, and then shift it by a predetermined bit. This is achieved by a pattern display method in which a pattern is written to the screen memory one word at a time at an arbitrary position.

Hereinafter, the present invention will be explained in detail with reference to the drawings.

FIG. 1 is a diagram explaining the present invention in detail, and 1 is a shift register (referred to as a processing register) for 2 words (32×2 bits).

The shaded area 2 is a pattern for one word (referred to as an update pattern) read out from a character generator (referred to as CG).
3 is the storage location of An, and 3 is the address of the refresh memory where the update pattern read from the CG is to be written.

When An+1, 4 is a 2-word shift register (hereinafter referred to as old register) that stores the pattern read from addresses An and An+1 of the refresh memory (hereinafter referred to as old pattern), and 4 is a 2-word mask. This is a register, and the shaded area 5 indicates the position where a new pattern is written.

The one word pattern read from the CG is first stored in bits 1 to 32 of the processing register 1.

Next, since the number of bits to be shifted is instructed as described later, the pattern is shifted by the specified number of bits (n bits) based on the instruction.

However, the position of the new pattern after the shift is as indicated by diagonal lines in figure b.

Next, the old patterns are read from the addresses An and An+1 of the refresh memory where the patterns are to be written and stored in the old register 3, respectively.

On the other hand, in the mask register 4, bits 1 to 32 are set in advance.
V'' has been written, and in synchronization with the shift of the pattern of the processing register 1, the at 1py is shifted to the right by n bits and becomes the state d.

After the above processing is performed, a new pattern is written to the screen memory or an old pattern and a new pattern are written in an overlapping manner.

(1) Update writing Update writing is to erase the old pattern at the position where the new pattern is written and write the new pattern at that position, which corresponds to the shaded part of the mask register 4 among the contents of the old register 3. The contents (contents of n+1 to 32+n bits) are cleared, and this and the contents of the processing register are □xed to address An, An+7n+7 of the refresh memory.

(2) Overwriting Overwriting is a method in which new and old patterns are mixed and written.The contents of processing register 1 and the contents of old register 3 are mixed, that is, the contents of processing register 1 and old register 3 are mixed. Mix the contents of the bits and put it at address An.
This is done by mixing the contents of 33 to 64 bits and storing them in An+1.

FIG. 2 shows an embodiment of the present invention, in which 1, 3, and 4 are the processing register, old register, and mask register shown in FIG. 8 is a refresh counter; 9 is a gate that sets the contents of either the address buffer or the refresh counter in the address register 10; 10 is an address register: 1
1 is a screen memory; 12 is a processing register, an old register, a mask register, and a control signal RW1 from the control unit 6;
A multiplexer that receives 0L sets a predetermined pattern in a register 13; 13 is a register.

A pattern write address, bit processing information, and update write/overwrite command information are input to the control circuit 6 from a controller (not shown).

child! The bit processing information indicates the number of bits to be shifted and is a signal for displaying a pattern at an arbitrary position.

On the other hand, 32-bit character patterns generated from CG are stored in processing registers 101-32 bits.

In this state, the control circuit 6 first sends the write address An to the address buffer 7.

When writing, gate 9 serves to pass through the contents An of the address buffer, so that the write address An is set in address register 10.

When the write address is set, the old pattern at address 110An of the screen memory 110 is read out under the control of the control circuit 6 and stored in bits 1 to 32 of the old register 3.

Next, the contents of the address register 10 are incremented by one step, and the old pattern at address An+1 is similarly read out and stored in the old register 3033-64 bits.

When the reading of the old pattern is completed, the control circuit 6 generates a shift signal SS based on the input bit processing information to shift the contents of the processing register 1 and the mask register 4 by a predetermined bit.

At the same time, in the case of update writing, update write signal RW,
In addition, in the case of overwriting, the overwriting signal OL is sent to multiplexer 1.
Based on the overwrite or update write signal, the contents of bits 1 to 32 of the processed register, old register, and mask register are mixed and a predetermined pattern is set in the register 12.

After that, the pattern set in the register is controlled by the control circuit 5.
The screen memo is written to address An of January 0 under the control of .

Subsequently, a 33- to 64-bit pattern is similarly set in the register 12 and written to the screen memory An, 1,01, thereby completing the writing of the character pattern to an arbitrary position.

As described above, according to the present invention, a character pattern can be written at any arbitrary position on the screen memory, and therefore a flexible display device can be provided, which can be displayed at any arbitrary position on the screen.

Incidentally, when there is no need to change the display position, the character pattern can be written into the screen memory in exactly the same way by supplying the update command and address signal to the control circuit 6 without supplying the bit processing information.

[Brief explanation of the drawing]

FIG. 1 is a principle diagram of the present invention, and FIG. 2 is a block diagram of one embodiment of the present invention. In the figure, 1 is a processing register, 3 is an old register, 4 is a mask register, 6 is a control circuit, and 10 is a screen memory.

Claims (1)

[Claims] 1. In a display device that writes a predetermined pattern to a specified address of a screen memory and then reads and displays the pattern, a first shift register of n to 1 for storing a power new pattern to be written to the screen memory; a second shift register of n to 1 for reading and storing the old pattern at the address of the screen memory where the new pattern is written; and a third shift register of n to 1 for indicating the range in which the new pattern is to be written. after shifting the first shift register by a predetermined bit, combining the contents of the first shift register with the contents outside the range specified by a third shift register of the second shift register, A pattern display method at an arbitrary position, characterized in that one word is written into the screen memory.