JP2831691B2 - Graphic data processing device for mask ROM - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a graphic data processing apparatus for a mask ROM (Read Only Memory) for automatically generating layout data for a program from a bit pattern. It is.

(Prior art) Among read-only ROMs, mask ROMs are manufactured by manufacturers.
It is made by changing the mask (thin film having a different pattern depending on the stored data) used in the production of the device. In this mask ROM, information is written in a mask used in the manufacturing process and stored in the ROM, so rewriting is not possible. However, since a memory cell can be made with one transistor, integration is performed. High density and large capacity chips are possible.

FIG. 2 is a diagram showing a memory cell matrix of a general MOS type mask ROM. Memory cells are MOS transistors
If it is composed of 1,2 ..., for example, its MOS transistor
By changing the thickness of the oxide film in the gate portion of 1, 2,..., The presence or absence of the MOS transistor, that is, “1”, “0” (MOS transistor 1 is “1”, MOS transistor 2 is “0”) The storage content is determined by this pattern (ie, layout data).

FIG. 3 is a block diagram showing the configuration of a conventional mask ROM graphic data processing apparatus for generating such layout data.

This graphic data processing device has an input unit 9, an output side of the input unit 9 is connected to a processing unit body 10, and an output side of the processing unit body 10 is connected to an output unit 16 such as an external memory. ing. The processing device body 10 includes an additional data storage unit 11 including a memory, an operation unit 12 including a program storage memory, a counter and an operation circuit, a bit data storage unit 13 including a memory, a comparator 14, a memory An output data generation unit 15 having an arithmetic circuit and the like.

FIG. 4 is a flowchart of the graphic processing of FIG. 2, and the operation of FIG. 2 will be described with reference to FIG.

Generated graphic information A1 and graphic generation coordinate calculation formula from input unit 9
When A2 is input to the processing device main body 10, the generated graphic information A1 is sent to the additional data storage unit 11 (step 20).
The figure generation coordinate calculation formula A2 is stored in the memory in the calculation unit 12 (step 21). The graphic generation coordinate calculation formula A2 stored in the memory becomes an externally defined subroutine. Next, the bit pattern A3 is input from the input unit 9 for each word, and sent to the bit data storage unit 13. Bit pattern A3 is 1
Each time a word is input, the counter in the arithmetic unit 12 indicating the bit position is counted up through step 23 (steps 24 and 25), and the bit position is reduced until the bit position becomes smaller than the maximum value (step 26). The pattern A3 is input one word at a time.

The input bit pattern data for one word is sequentially compared and determined by the comparator 14 as to whether it is a graphic generation bit (“1” or “0”) (step 27). If the figure generation bit is "1", the comparator 14 accesses the operation unit 12 (step 28), and the operation unit 12 starts operation based on the information of the address and bit position stored in the bit data storage unit 13. Then, figure generation coordinate data A4 is calculated and sent to the output data generation unit 15 (steps 21, 29). Repeat this for all words through steps 22-29,
All figure generation coordinate data D is stored in the output data generation unit 15.

When the input of all the words is completed (step 23), the generated graphic information A1 stored in the additional data storage unit 11 and the all graphic generation coordinate data A4 are combined in the output data generation unit 15, and the graphic data with complete coordinates is obtained. Is generated. Thereafter, the graphic data is converted into layout data such as a standard format (hereinafter, referred to as GDS II) or the like used for mask processing by the output data generation unit 15 (step 30) and sent to the external output unit 16 (step 30). 31), a series of work is completed.

Then, a mask is created based on the layout data in the output unit 16, and writing to the memory cell matrix, that is, programming is performed using the mask, thereby obtaining a mask ROM as shown in FIG.

(Problems to be Solved by the Invention) However, in the apparatus having the above configuration, the layout data to be generated becomes enormous with the increase in the capacity of the mask ROM, and the memory of the output data generation unit 15 and the output unit 16 The hardware capacity becomes very large, and it is difficult to reduce the size of the device.

SUMMARY OF THE INVENTION The present invention solves the problem of the prior art that the mask ROM has a large memory capacity for storing processing data due to an increase in the amount of layout data due to an increase in the capacity of the mask ROM. The present invention provides a graphic data processing device.

(Means for Solving the Problems) In order to solve the above problems, the present invention provides a mask ROM graphic data processing apparatus for generating mask ROM program layout data from bit data by using at least bit data and an arithmetic expression. Based on the input unit to be input and the x and y coordinates of the figure to be generated based on the bit data, the width and height of a square (rectangular, that is, a rectangle, or a positive direction), the pitch in the x direction, and the figure in the y direction An arithmetic unit for calculating a pitch, an additional data processing unit, and an output data generating unit for converting an output of the additional data processing unit into a graphic format and outputting program layout data. Here, the additional data processing unit merges adjacent graphics having the same x-coordinate interval within the range of the x-direction graphic merging pitch into the same graphic between figures having the same y-coordinate rectangle height and y-direction graphic merging pitch. And a function of merging adjacent graphics whose intervals of the y coordinate are within the range of the y-direction graphic merging pitch between figures having the same x coordinate, rectangular width, and x-direction graphic merging pitch into the same graphic. I have.

(Operation) According to the present invention, since the graphic data processing device for a mask ROM is configured as described above, the arithmetic unit generates desired graphic data based on the input bit data and generates Give to the processing unit. The additional data processing unit merges adjacent graphics within the merge pitch and outputs graphic data to the output data generation unit. The output data generation unit converts the graphic data into program layout data and outputs the program layout data. As a result, a large amount of data is compressed, and the amount of memory hardware in the device for storing the data can be reduced. Therefore, the above problem can be solved.

(Embodiment) FIG. 1 is a block diagram showing a configuration of a mask ROM graphic data processing apparatus according to an embodiment of the present invention.

This graphic data processing device has an input unit 39 including a keyboard or the like for inputting a bit pattern B1, a graphic generation coordinate calculation formula B2, and the like, and a processing device main body 40 is connected to an output side of the input unit 19, Further, an output unit 46 such as an external memory or a display is connected to an output side of the processing device main body 40.

The processing device body 40 has bit data for each word, that is, a bit data storage unit 41 including a memory for storing the bit pattern B1, a program storage memory, a counter, an arithmetic circuit, and the like. And a calculation unit 43 for determining the bit data storage unit 41.
Is connected to a calculation unit 43 via a comparator 42 for judging figure generation bits. An output side of the operation unit 43 is connected to an additional data processing unit 44 having a memory, an operation circuit and the like and having a graphic merging function, and an output data generation unit 45 is connected to the output side. The output data generation unit 45 includes:
It has a format conversion function of converting the output of the additional data processing unit 44 into a graphic format such as GDS II to generate layout data, and is composed of a memory and an arithmetic circuit, and the output unit 46 is connected to the output side Have been.

FIG. 5 is a flowchart of the graphic processing of FIG. 1, FIG. 6 is a diagram showing the contents of graphic data processed by the arithmetic unit 43 of FIG. 1, and FIGS. FIG. 3 is an explanatory diagram showing a merging method (merging procedure), and the operation of FIG. 1 will be described with reference to these figures.

In the flowchart of FIG.
When the bit pattern B1 for one word and the graphic generation coordinate calculation formula B2 are input to the processing device body 40, the bit pattern B1 for one word is input to the bit data storage unit 41 (step 50). The graphic generation coordinate calculation formula B2 is stored in the memory in the calculation unit 43 (step 51). The graphic generation coordinate calculation formula B2 stored in this memory becomes an externally defined subroutine. Next, the bit pattern B1 for one word input to the bit data storage unit 41 is subjected to the input end determination step 52 for all words to determine whether or not the bit pattern B1 is graphic generation data by the comparator 42. The arithmetic unit 43 is accessed based on the. The operation unit 43 calls the external definition subroutine stored in the memory based on the result of the determination (step 53), and gives an address and a bit pattern to extract a graphic generation bit for each graphic (step 51-1). ), Calculation of figure generation coordinates (X, Y) (Step 5
1-2), for example, a rectangular width and height as a square (W, determination of H) (step 51-3), x-direction graphic merged pitch P _X and y directions graphic merging pitch is more graphic compression process data
A process for determining P _Y is performed (step 51-4). The graphic data output (X, Y, W, H, P _X , P _Y ) of the arithmetic unit 43 is sent to the additional data processing unit 44 (Step 54).

FIG. 6 shows graphic data processed by the arithmetic unit 43. In Figure 6, X is for example the lower left x coordinate of the graphic to be generated, Y is for example the lower left y coordinate of the graphic to be generated, W is the width of the rectangle, H is the height of the rectangle, P _X is the x-direction of the figure merging pitch, P _Y indicates the figure merging pitch in the y direction.

In the graphic processing flowchart of FIG. 5, when data input of all words is completed (step 52), the additional data processing unit 44 merges adjacent graphics within the merging pitch based on the graphic data output of the arithmetic unit 43 (step 52). Step 55),
After the merging process, the graphic data output (X, Y, W, H) is sent to the output data generator 45 (step 56). FIGS. 7 (a) and 7 (b) show the procedure for merging adjacent generated graphics in the additional data processing section 44. FIG.

As shown in FIGS. 7 (a) and 7 (b), the combined use of graphic data, ie, compression, is performed in two steps.
In step 1 shown in FIG. 7A, the generated graphics are merged in the x direction, and in step 2 shown in FIG.
The figures merged in the x direction are further merged in the y direction.

That is, in step 1 of FIG. 7 (a), the graphic data is sorted using, for example, the lower left y coordinate of the graphic generation as the first key and the lower left x coordinate of the graphic generation as the second key. When the following conditions (1) to (4) are satisfied for the figures, the two figures are merged to reduce the space between the figures in the x direction.

Y _i = Y _{i + 1} ... (1) H _i = H _{i + 1} ... (2) P _Yi = P _{Yi + 1} ... (3) X _i + P _Xi ≥X _{i + 1} ... (4) That is, adjacent figures whose Y, H, and P _Y are equal and whose _X interval is within the range of P _X are merged. After the merging, the figure generation coordinates (X _i , Y _i ) and the width and height of the rectangle (X _{i + 1} −X _i + W _{i + 1} , H _i )
The figure merging pitch in the x direction and the figure merging pitch in the y direction are (X _{i + 1}
−X _i + P _{Xi + 1} , P _Yi ), and the above-described merging operation is repeated with the next figure. FIG. 7 (a) shows four figures before merging on the left side, and these figures become two figures on the right side by merging.

In step 2 of FIG. 7 (b), the figure data merged in the x direction in step 1 is converted to a first key by, for example, a lower left x coordinate for generating a figure, and a second key is converted to a second y coordinate, for example, by lower left.
Sort again as key. When the conditions of the following equations (5) to (8) are satisfied for the j-th and j + 1-th graphics, the two graphics are merged to reduce the space between the graphics in the y direction.

X _j = X _{j + 1} (5) W _j = W _{j + 1} (6) P _Xj = P _{Xj + 1} (7) Y _j + P _Yj ≧ Y _{j + 1} (8) That is, adjacent graphics whose X, W, and P _X are equal and whose _Y interval is within the range of P _Y are merged. For the figure after merging, the figure generation coordinates are (X _j , Y _j ), and the width and height of the rectangle are (W _j , Y _{j + 1} −Y _j +
_{Hj + 1} ), the x-direction figure merging pitch and the y-direction figure merging pitch are set to (P _Xj , Y _{j + 1} −Y _j + P _{Yj + 1} ), and the above merging operation is repeated with the next figure. FIG. 7 (b) shows four figures before merging on the left side and two figures on the right side due to merging.

After the merging process as described above, when the graphic data output of the additional data processing unit 44 is sent to the output data generating unit 45, the output data generating unit 45 converts the graphic data into GDS data as shown in the flowchart of FIG. (Step 57), and the layout data is output to an external output unit.
Output to 46 (step 58). Thus, a series of operations is completed.

FIG. 8 is a diagram showing an example of a memory cell matrix in a mask ROM formed using the layout data of the present embodiment. Data "1" or "0" is written in each memory cell 60, and the area 61 adjacent to the memory cell (ie, MOS transistor) to which data "1" is written is set to 1
Is recognized as one processing pattern. In other words, the merged pattern area 61 of adjacent data “1” is regarded as having one layout data, and is processed. Therefore, the number of layout data is reduced, the amount of hardware of the memory in the output data generation unit 45, the output unit 46, and the like can be significantly reduced, and the device can be downsized.

Note that the present invention is not limited to the illustrated embodiment, and various modifications are possible. For example, there are the following modifications.

(I) In FIG. 7, the merging procedure may be configured to perform merging processing in the x direction after merging the generated graphics in the y direction.

(Ii) In FIGS. 6 and 7, the figure may be a square. Further, the coordinate origin (X, Y) of the generated graphic can be set at an arbitrary position on the upper left, upper right, or lower right of the graphic.

(Iii) The above embodiment can be applied to a mask ROM or the like using a bipolar transistor.

(Effects of the Invention) As described above in detail, according to the present invention, the individual mask ROM bit pattern data (graphic data) is merged by the additional data processing unit.
A large amount of data can be compressed, and the hardware amount of the memory in the device can be reduced.

[Brief description of the drawings]

FIG. 1 is a block diagram showing the configuration of a mask ROM graphic data processing apparatus according to an embodiment of the present invention, FIG. 2 is a view showing a memory cell matrix of a general MOS type mask ROM, and FIG. Configuration block diagram of a graphics data processing device,
4 is a flowchart of the graphic processing of FIG. 3, FIG. 5 is a flowchart of the graphic processing of FIG. 1, FIG. 6 is the graphic data of FIG. 1, and FIGS. 7 (a) and 7 (b) are those of FIG. FIG. 8 is a diagram showing a method of merging adjacent generated graphics, and FIG. 8 is a diagram showing a memory cell matrix of a mask ROM in an embodiment of the present invention. 39 ... input unit, 40 ... processing device body, 41 ... bit data storage unit, 42 ... comparator, 43 ... arithmetic unit, 44 ... additional data processing unit, 45 output data generation unit, 46 ... Output part, X ...
... Figure generation x coordinate, Y... Figure generation y coordinate, W... Rectangle width, H... Rectangle height, P _X ... X direction figure combination pitch, P _Y.

Claims (1)

(57) [Claims] 1. A mask ROM graphic data processing device for generating mask ROM program layout data from bit data, comprising: an input unit for inputting bit data and an arithmetic expression; an arithmetic unit for calculating xy coordinates, rectangle width and height, x direction figure merging pitch, and y direction figure merging pitch; and x between figures having the same y coordinate direction height and y direction figure merging pitch. Adjacent figures whose coordinate intervals are within the range of the x-direction figure merging pitch are merged into the same figure, and the y-coordinate distance between figures having the same x-coordinate, rectangle width, and x-direction figure merging pitch is the same as the y figure. An additional data processing unit for merging adjacent graphics within the range of the direction graphic merging pitch into the same graphic, and converting the output of the additional data processing unit into a graphic format and A graphic data processing device for a mask ROM, comprising: an output data generation unit that outputs program layout data.