JPS61107290A - Drawing controller - 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] [Technical field of invention] The present invention relates to a drawing control device for a bitmap memory.

[Technical background of the invention and its problems] In a display device having a bitmap memory, when drawing a dot font of a character and image data in the bitmap memory, an arbitrary number of dots are drawn from an arbitrary position. A means is needed to do so.

Conventionally, when such a drawing means is implemented, the drawing control is performed on a dot-by-dot basis, resulting in a problem that the drawing speed is slow.

Therefore, by performing the above-mentioned drawing control on a word-by-word basis, the drawing speed can be significantly increased. However, in the conventional technology, when the function is configured to draw in units of words, there is a drawback that it is not possible to draw an arbitrary number of dots from an arbitrary position.

[Object of the Invention] The present invention has been made in view of the above-mentioned circumstances, and it is an object of the present invention to provide a drawing control device that can draw a dot image by an arbitrary number of dots from an arbitrary dot position in word units on a bitmap memory. purpose.

[Summary of the Invention] The present invention uses a mask circuit to enable drawing in units of words when it is desired to draw an arbitrary number of dots from an arbitrary dot position in a bitmap memory, thereby increasing the drawing speed. can be significantly improved.

[Embodiments of the invention] An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing an embodiment of the present invention. In the figure, 11 is a microprocessor (μP) that controls the entire device. 12 is a start flag set signal (STA: This is a mask mode file that is latched by the end flag set signal (END: set when it is at the left end in the X direction) and the end flag set signal (END: set when it is at the right end in the X direction). The mask mode designation data (MK-MOD) stored in this mask mode file 12 is '1”H.
1 bit valid at 72''H, 1 bit valid at F''H
5 bits are valid, 'O''H indicates 16 bits are valid.

Reference numeral 13 denotes a character font ROM that sequentially outputs a character font of 24×24 dots per character in units of slices according to a character designation address (CH-ADD).

14 stores the character font data (CH-DOT) output from the character font ROM 13, and stores the shift value (SFT
-DT) is a barrel shifter that performs an O-tate shift. 15 converts the 8MM write data (BMM-WTDT) output from the barrel shifter 14 into the two-dimensional address (BMM-ADD) and the BMM mask signal ($CA
This is a bit map memory (BMM) that stores data according to the S.0F-00/1F to 10).

A mask register 16 outputs mask information (MK-DOT.OF~00/1F~10) according to the drawing start dot position designation information (DOT-AD) and the drawing dot unit designation information (MK-MOD).

17 is a two-dimensional DMA device that directly accesses and controls the bitmap memory 15; 18 is mask information (MK-D) output from the mask register 16;

BMM based on T-OF-00/IF~10) and CAS C column address strobe) signal ($CAS)
This is a Nant gate that generates a mask signal ($CAS・OF~00/1F~10).

19 is display output data from the bitmap memory 15 (
This is a shift register (P-8) that outputs 8MM-D15P) as a bit serial video signal. 20 is a CR7 display section that displays characters, graphics, etc. 21 is a mask dot file that stores a drawing start dot address (MKD-ADD). 22 is a DMA address (DMA-ADD) output from the two-dimensional DMA device 17
and the drawing start dot address (MKD-ADD) output from the mask dot file 21, and one of them is used as the drawing start dot position designation information (DOT-AD).
), and when the start flag set signal (STA) is valid (when the flag is set)
At this point, the drawing start dot address (MKD-ADD) output from the mask dot file 21 is selected.

2 to 5 are for explaining the operation of the above embodiment, and FIG. 2 shows an example of character font R.
An operation explanatory diagram showing the character font when the character (large) output from the OM 13 is shifted by 4 bits and drawn on the bitmap memory 15. Figure 3 shows the relationship between the mask information and the shift value at the time of drawing. Figure 4(a), (
b) is a diagram showing the contents of the mask register 16 at the time of the same drawing, and FIG. 5 is a diagram showing an example of the data set of the mask mode file 12 and the mask dot file 21 at the time of the same drawing.

Here, the operation of one embodiment will be explained with reference to the above-mentioned FIGS. 1 to 5. Here, as shown in FIG. 2, a case will be taken as an example in which a "large" character font (24×24 dots) output from the character font ROM 13 is shifted by 4 pits and drawn in the bitmap memory 15.

First, the microprocessor 11 operates as a two-dimensional DMA device 1.
Parameters for generating an address (CH-ADD) specifying a "large" character to be displayed and output are set on the source side of No. 7. Next, an 8MM address (BMM-ADD) and a DMA address (DMA
-ADD: Here, the parameter (address for drawing from the 4th bit) is set. Also, shift l to barrel shifter 14! (SFT-DT: Here “
4)).

1 Next, the drawing dot unit designation information (MK-MOD) is set in the mask mode file 12.

Here, as shown in FIG.
Set the drawing dot unit specification information (MK-MOD-“O”H) that makes 16 bits valid at address 01 of 2, and set the drawing dot unit specification information that makes 8 bits valid at address 02 of the same file (MK-MOD-“O”H). MOD-8"H).Here, address 01 of the mask mode file 12 is set when the start flag set signal (STA) in the X direction is set (set at the right end in the X direction), and address 02 of the mask mode file 12 is set. The address is accessed when the end flag set signal (END) is set (set when the end flag is set at the right end in the X direction).

Additionally, address 01 of the mask dot file 21 contains a drawing start dot address (MKD-ADD; here, 4 of 1 word) that indicates from which dot drawing should start.
"04"n) is set to instruct drawing from the number.

In this way, after setting each of the above parameters, Yukae. MA1i1171C Yu, -88ka19,6. □21・
As shown in □ and FIG. 3, first, the 16 pits to the left of the character "large" are shifted by the barrel shifter 14. This data is then stored as mask information (MK-DOT・OF ~00.MK
-DOT-IF~10) J: is drawn at the valid pit position (■). That is, in this case, address 01 of the mask mode file 12 and mask dot file 21 shown in FIG. The contents of the address (*1) are output, and this “
Bit mask information 1 that enables each bit of OB"H-OO"H, "IF"H to "10"H
BMM'? generated from the contents of (MK-DOT-OF~00/1 F~10) and the CAS signal ($CAS>)?
The write data (BMM-WTDT) of the bit map memory 15 as shown in FIG. 3 is masked by mask signals ($CAS.OF to Oo/1F to 10).

In the next word, the eight bits to the right of the character "large" are shifted by four bits by the barrel shifter 14.

This data is stored in the third bitmap memory 15.
Mask information shown in the figure (MK-DOT・OF~00, MK
-DOT-IF~10) is drawn at the bit position (■) that has become valid. That is, at this time, address 02 of the mask mode file 12 and mask dot file 21 shown in FIG. Since the drawing start dot address (MKD-ADD) output from the mask dot file 21 is not received, the address DMA address (DM
A-ADD) is selected, and this is mask register 1.
6, the contents (*2) of address 14 of the mask table shown in Figure 4(b) are output, and this jl
BMM generated from the contents of bit mask information (MK-DOT-OF~00/IF~10) and CAS signal ($CAs) to enable B ” H-14” H pit.
The mask signal ($CAS-oF~00/1F~10) performs mask control on the write data (BMM-WTDT) of the bitmap memory 15 as shown in FIG. 3.

When the writing in the X direction of the bitmap memory 15 is completed in this way, the two-dimensional DMA device 11 increments the Y direction address and controls the drawing of the next raster (slice line) in the X direction in the same manner as described above. .

Such drawing processing is performed sequentially, and the drawing processing for one character is completed by drawing 24 rasters.

As described above, by setting the mask information once through one data transfer, when it is desired to draw an arbitrary number of dots from an arbitrary dot position in the bitmap memory, the drawing speed can be greatly improved.

[Effects of the Invention] As described in detail above, the drawing control device of the present invention includes a barrel shifter for storing and rotating image information written in a bitmap memory, a means for specifying a dot shift value of the barrel shifter, and a means for specifying a dot shift value of the barrel shifter; A two-dimensional DMA device that controls access to a bitmap memory, a mask dot file that specifies a starting position for drawing image information stored in the barrel shifter into the bitmap memory, and a mask mode file that specifies dot units for the drawing. and a mask circuit that masks the information written to the bitmap memory in units of dots based on the contents of the mask dot file and the mask mode file. By configuring the image information to be drawn from any dot position specified in the file in units of any number of dots specified in the mask mode file, any number of dots can be drawn from any dot position in the bitmap memory. When desired, the mask circuit can be used to perform high-speed drawing on a word-by-word basis, greatly increasing the drawing speed.

[Brief explanation of drawings]

;1 FIG. 1 is a block diagram showing an embodiment of the present invention;
1. Figures 2 to 5 are for explaining the operation of the above embodiment, respectively. Figure 2 shows the character font when the characters output from the character font R0M are shifted by 4 points and drawn in the bitmap memory. FIG. 3 is a diagram showing the relationship between mask information and shift values at the time of drawing,
Figure 4(a). (b) is a diagram showing the contents of the mask register at the time of the same drawing, and the fifth figure is a diagram showing an example of the data set of the mask mode file and the mask dot file at the time of the same drawing. 11...Microprocessor (μp), 12...Mask mode file, 13...Character font ROM,
14...Barrel shifter, 15...Bit map memory (BMM), 16...Mask register, 17...
Two-dimensional DMA device, 18... Nantes Gate, 19...
・Shift register, 20...CR7 display section, 21...
・Mask dot file, 22...Selector, STA
...Start flag set signal, END...End flag set signal, MK-MOD...Mask mode specification data, CH-DOT...Character font data, B
M M -W T D T-...8MM write data, CH-ADD...Character specification address, BMM-AD
D...8MM address, MK-DOT・0F~00/
IF~10...Mask information, $CAS...Column address strobe signal, $CAS-OF~00/I
F~10...BMM mask signal, BMM-DISP・
...Display output data. Applicant's representative Patent attorney Takehiko Suzue Figure 1 Figure 2 Figure 4 Figure 5 Square 2 mode 1 square 2 dots

Claims (1)

[Claims] a bitmap memory; a barrel shifter for storing and rotating image information written in the bitmap memory; means for specifying a dot shift value of the barrel shifter; a two-dimensional DMA device for controlling access to the bitmap memory; A mask dot file that specifies the drawing start position of the image information stored in the barrel shifter in the bitmap memory, a mask mode file that specifies the dot unit of the drawing, and the contents of the mask dot file and the mask mode file. It also has a mask circuit that masks information written to the bitmap memory in units of dots, and the information specified by the mask mode file starts from any dot position specified by the mask dot file on the bitmap memory. A drawing control device that draws image information in arbitrary dot units.