JPS61151590A - Data writing 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 (a) Technical Field of the Invention The present invention relates to a data writing method for writing data into a display memory or the like.

('b) In the prior art, a bitmap display is used for graphical display, in which the problem display screen and the display memory correspond on a one-to-one basis. In such a display, display data (pattern data) such as characters and figures is assembled in a processing device, and this is sometimes written directly into a display memory. When writing character display data to the display memory using this method, if the write direction (address progression direction) to the memory is only one direction (for example, horizontal direction), the amount of data to be written will inevitably increase. In addition, there was a drawback that writing control was complicated.

(0) Purpose of the invention The present invention was made to solve the above-mentioned drawbacks.
The purpose of this invention is to provide a data writing method that makes it easy to write data to memory.

(d) Structure of the Invention The present invention provides a write method for writing data consisting of 2N bytes into a memory, which includes: a register in which a write address is set; a counter that counts the number of bytes of the data;
a first address counter that selects an address in a first direction of the memory; and a second address counter that selects an address in a second direction perpendicular to the first direction; The byte unit data is written in the first direction of the memory by incrementing the address counter, and when the number of written data reaches N, the second address counter is incremented by one and the data is written in the first direction of the memory. , the data in units of bytes is written in the first direction of the memory by initializing the first address counter and incrementing the first address counter again. This is an all-inclusive method. As described above, the present invention writes N (for example, 16) pieces of character display data consisting of 2N bytes in the vertical direction of the memory, and then writes data in bytes to the address position to the right of the character display data. By writing N (16) pieces of , a total of 2N (2X16
=32) bytes of data are written.

(e) Examples of the invention The present invention will be explained below with reference to the drawings. The drawing is a block diagram illustrating an embodiment of the present invention.

Display data C from the control unit (processing device) 1 in the drawing
B+-831) is written into the memory 3 in units of bytes (B) by driving the writing section 2 with the pulse P. It is assumed that display data for one character is composed of 16×16=256 bits, and the embodiment uses this display data (25
In this example, data (6 bits) is divided into 32 times in units of bytes (8 bits) and written to the memory 3. In the present invention, when writing a character into a display memory, one character is divided into two parts, and display data for the left half is written first, and then display data for the right half is written. As shown in the memory 3 in the drawings, 1
Of the 32 bytes of display data (B/-B) that make up the character, B/"B/6 is placed in the upper left (7)7')'L/s
Write downward from 1 to address el&, then to the upper right address 13/? Display data B/7 to B3) are written in byte units downward from address e3z. In the following figure, which describes the operation of this writing example, the switching units 4 and 5 are connected to the contacts (b) by a switching command C from the control unit 1. Next, control section 1
sends out display data B/-B3z sequentially in bytes to the writing section 2, and emits a pulse P every time this display data is sent out in bytes. The writing section 2 is driven by this pulse P, and display data B/ is written to the address et. On the other hand, the pulse P passes through the contact (b) of the switching section 5 and causes the address counter (for vertical address) 6 to increment by one.

Since the value of this address counter is set in the address register 8 via the OR circuit 7, the address e2 is selected and the writing position of the next display data B2 is determined. On the other hand, the pulse P is sent to a counter (hexadecimal) 9, and the number of pulses is counted. By repeating the above operation, when writing of display data B1-B1≦ is completed from address e to e/4, the count value of counter 9 reaches (16), so at this time pulse P2. is output. This pulse P/4 passes through the contact (b) of the switching section 4 and causes the address counter (for horizontal address) 10 to increment by one. The value of this address counter 1° is immediately transferred to address register 1.
1, so the horizontal address f2 of the memory 3 is selected. Also, register 12 address data is set in address counter 6 by pulse Pt6 (initialization)
Therefore, by repeating the above write operation, display data B // is written downward from address e7 in memory 3.
7 to Btx are written. The address data in the register 12 is set in the counter 6 by the pulse Pl& emitted when the counter 9 counts out, and the next character address is selected.As is clear from 0 or more, in the Greif ink display, When writing display data for characters directly into the display memory (memory 3) from the processing device, the above writing operation transfers data related to the required writing position and controls the writing. Just do it.

When the switching units 4 and 5 are switched to the contact point (A) by the control command C from the control unit 1, this is an example of writing display data in the horizontal direction. In this case, the pulse P from the control unit 1 passes through the contact (a) of the switching unit 4 and is output to the address counter 10.
, the addresses in the horizontal direction of the memory 3 are sequentially selected, and the display data from the control section 1 is sequentially written in the horizontal direction in byte units. The carry signal Hc issued when the address counter 10 counts out drives the address counter 6 via the contact (A) of the switching section 5, so that the next vertical address is selected.

Moreover, when switching parts 4 and 5 are switched to contacts (c), the address counter 6 is
In this example, the address counter 10 is incremented by one and the address counter 10 is incremented and written every time the carry signal Vc of the address counter 6 is output. According to this embodiment, there is an effect that the control for writing a multi-byte pattern such as an α·N pattern into the display memory is simplified.

(f) Effects of the Invention As described above, the present invention has the advantage of simplifying write control when directly writing data from a processing device to a memory.

[Brief explanation of drawings]

The drawing is a block diagram illustrating an embodiment of the present invention,
The symbols used in the figure are as follows. 1 is a control unit (processing device), 2 is a writing unit, 3 is a memory, 4
．． 5 is a switching section, 6 is an address counter (for vertical address >, a, 11.12 is an address register, 9 is a counter (for pulse counting), 13 is a display section, 14 is an AND circuit,
A is address data. B7. B, L, Btb, B/? , Btg+ BQ is display data (byte unit data), C is a switching command, e,. e/ri is the address, f7. f2 is a horizontal address, HC is a carry signal (horizontal), and P and P/4 are pulses. Vc indicates a carry signal (vertical).

Claims (1)

[Claims] In a write method for writing data consisting of 2N bytes into a memory, a counter counts the number of bytes of the data, and a first selector selects an address in a first direction of the memory.
and a second address counter that selects an address in a second direction perpendicular to the first direction, and by incrementing the first address counter, the byte unit data is read. writing in the first direction of the memory, and when the number of written data reaches N, incrementing the second address counter by one;
Data writing characterized in that after initializing the first address counter, the first address counter is incremented again to write the data in units of bytes in the first direction of the memory. method.