JPS6032092A - Attribute 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] The present invention relates to an L tributary control system.

Generally, when displaying characters on a CRT display, a bitmap method is used, in which the dot composition of the characters is stored in memory as is, and then read out and displayed in accordance with the raster movement.
There is a code reche method in which a character code is stored in a memory, the memory is read out in response to raster operations, and the output of a character generator that stores character dots is displayed.

In these cases, an tribute code is required to define the attributes of a series of data on the screen.

As a conventional A) +7-bit control method, there is a method in which a part of the display character area is collapsed to provide a secondary code to the tributary code. A simple illustration of this is shown in Fig. This means that the attributive code 1 is always inserted at the location where the attribute of a character changes, and in this way, the attributive code occupies the area of one character.

In the above method, when the changing point of an attribute is changed, the previous behavior remains valid until the next changing point, and if this is an attribute such as inversion or blinking highlight, it will flicker when viewed. Figure 2 is a diagram explaining this phenomenon, with 3-line inverted characters, 4. 5. 6゜7 is the attribute code, 2
is a highlighted character.

Here, when attempting to shift the inversion position from 5 to 5' by one character, the device 5 is set to τ6 and the inversion end degree is written in the next position 5'. At this time, the inversion is instantaneously performed to the next highlight start position during the time between erasing and next writing. This is possible because the attribute code is attached at the change point.

As a way to remove such flickering, you can add one attribute code to each character, thereby reducing the range affected by the attribute code by one.
One idea is to limit the rewriting to characters so that the effects of rewriting do not spread over a wide area.

Generally, the display and display is controlled by a microcomputer, and the bit width that can be read and written to 6D and -[ is generally 8 bits or 16 bits.

Therefore, the refresh memory is often composed of 8 pits. As shown in Figure 3, if you have an 8-bit attribute code memory 31 for a pair of 8-bit character code memories 32, it would be easier if you had a 16-bit CPU because you could read and write at the same time. )
In the CPU, the data must be divided into two parts and read/written every 8 pits.

In such a case, the present invention provides a character code memory and an attribute code memory that are divided into separate areas of the memory, and are accessed completely separately from the CPU. The number of meaningful bits has been increased to eliminate flickering on the screen.

According to the present invention, in a CRT display device that performs display by storing character codes and refreshing them, the code memory for character codes and the code memory for attributive codes for determining their attributes are separated into separate areas of the memory. , one attribute code corresponds to one character, the character code memory and attribute code are accessed separately when UPLI is serially read/write, and the code is set when -@-1#=@- screen display. An attribute control method is obtained that is characterized by accessing memory and attribute memory simultaneously.

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 4 is a diagram showing an example of a memory map used in the present invention. In this example, the first 400 addresses are used as a character code memory 41 to store character codes. Later 800
The attribute code is stored as an attribute code memory 42 up to the address.

FIG. 5 shows a block diagram of an embodiment of the present invention. In FIG. 5, a CRT controller 51 gives addresses of characters to be displayed to an attribute code memory 52 and a character code memory 53 in accordance with the operation of a display raster. It is something. Character code memory 53 is a memory in which character codes are stored for characters to be displayed. The attribute code memory 52 is a memory for attribute codes indicating attributes of characters to be displayed, and is generally given meaning in bit correspondence. CG55 is a ROM that stores the character DRA) 1ris configuration. The latch 54 is a temporary storage register that is used to match the delay between character display and attribute code. 56 is a Fi attribute control circuit, and 57 is a shift register.

In this way, the character code memory 5-3 and the attribute code memory 52 are provided in separate memory areas 1 (divided), and during display operation, both memories are accessed simultaneously, and the CPU
They are accessed separately when reading and writing from.

Here, the lower 10 bits are common, and if the upper 11th bit is 0, the character code 1 becomes an attribute code.

Therefore, during display operation, the 11th bit is ignored, and when accessed by the CPU, the 11th bit is treated as valid and separated, so that it can be accessed separately.

According to the present invention, as described above, there is a young fruit h which can prevent screen flickering and expand the bit width of the attribute code.

[Brief explanation of drawings]

Figures 1 and 2 are diagrams explaining the arrangement of conventional attribute codes, Figure 3 is a diagram showing an example of the arrangement of the attribute code memory and character code memory, and Figure 4 is the diagram illustrating the arrangement of attribute codes in the present invention. FIG. 5, which is a diagram showing an example of the arrangement of the code memory and character code memory, is a block diagram of an embodiment of the present invention. 51...CRT controller, 52...
・Attribute code memory, 53...1 character code memory, 54...Latch, 55...
...CG, 56... Attribute control circuit, 57... Shift register, 58...
C.R.T. vr Figure z 2 Figure cod 3 ■ Memory?・Knob Y 4 Figure L 5 Figure

Claims (1)

[Claims] In a CRT display device that performs display by storing and refreshing character codes, a code memory for the character code and a code memory for the tributary code that determines its consistency are provided in separate areas of the memory. 1. Attribute code memory is accessed separately when reading/writing from the central control unit, and code memory and attribute code memory are accessed simultaneously when displaying on screen. An attribute control method characterized by: