JP3199832B2 - Data library generator for CAD for LSI design - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for generating a data library for a CAD for LSI design, and more particularly to an apparatus for generating a data library for each component used in a CAD tool for performing an ASIC design.

[0002]

2. Description of the Related Art In general, an LSI design process is performed by sequentially passing through a functional design stage, a logic design stage, a circuit design stage, and a layout design stage. And 1
In one design stage, design processing is performed using design component data created in the previous design stage. Normally,
In order to support the design at each stage, separate CAD tools are prepared, and the design is performed by these CAD tools. For this reason, the design component data of the LSI is separately managed for each CAD tool.

[0003] In recent years, the use of LSIs has been expanding more and more, and so-called ASICs (application-specific integrated circuits) have been developed.
Is increasing year by year. In the ASIC, it is necessary to design a relatively large-scale circuit in a short time according to the requirements of each user. For this reason, a semiconductor maker provides a user with a large number of LSI design component data for each CAD tool as a library, and the user combines desired design component data in the provided library to create a desired LSI design. A system to do this is adopted.
In other words, a semiconductor maker prepares a large number of LSI design parts data as individual parts in advance, and the user can use the necessary parts from among them to obtain a desired LSI.
The work of assembling I will be performed.

[0004]

The LSI manufacturing process has made technological progress year by year, and high performance and miniaturization of integrated circuits have been achieved. Each time such high performance and miniaturization are achieved, it is necessary to update individual components for assembling the ASIC, that is, LSI design component data. That is, it is necessary to update the data library prepared for each CAD tool.

However, since the plurality of design component data constituting the data library have a complicated relationship with each other, the work of updating the data library is extremely complicated. In addition, it is necessary to update the library for each CAD tool.

Accordingly, the present invention provides various LSI design CAs.
It is an object of the present invention to provide an apparatus that can easily update a data library supplied to a D tool.

[0007]

Means for Solving the Problems (1) The first invention of the present application is a device for generating a data library of various components used in a CAD tool for performing LSI design, by converting desired component data to the component data. An element extracting unit for extracting a specific internal element, a component synthesizing unit for synthesizing a new component data by synthesizing an element existing in the desired component data or an element input from the outside, and a synthesized component A design component data storage unit for storing data, a process data storage unit for storing a process of an extraction process performed by the element extraction unit and a synthesis process performed by the component synthesis unit, and a search tool based on search information from the CAD tool. Data search means for searching for specific data from the data in the design part data storage means, and the data search means Format conversion means for converting the data retrieved by the method so as to conform to the format of the CAD tool; input means for inputting data or instructions to the element extracting means and the component synthesizing means;
Is provided.

(2) The second invention of the present application is the device according to the first invention, wherein the expression conversion means for generating another element by converting the expression of an element existing in the desired part data. Further, a process of the expression conversion processing by the expression conversion means is stored in the process data storage means.

[0009]

In the apparatus of the present invention, when the extraction processing is performed by the element extracting means or when the combining processing is performed by the component combining means, the processing of these processings is stored as process data. That is, by using the elements extracted from which component data and how to perform the synthesis, information indicating which component is synthesized remains as process data. By leaving such process data, in the future,
When specific component data is updated, it is possible to obtain information about which other component data this update will affect, and this process data can be used to easily update other component data. It can be carried out. Further, the data search means is based on search information from the CAD tool,
The data required by the CAD tool can be searched. This data is prepared in a common format that does not depend on a specific CAD tool, and is supplied to each CAD tool after the format is converted by a format conversion unit so as to be compatible with the CAD tool. Therefore,
Parts data can be managed centrally.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS §1 Overall Configuration of Apparatus Hereinafter, the present invention will be described based on an embodiment illustrating the present invention. FIG. 1 is a block diagram showing a basic configuration of an LSI design CAD data library generation apparatus according to an embodiment of the present invention. This device comprises a storage means 10, an element extraction means 20,
Component synthesizing means 30, expression converting means 40, input means 50,
It comprises a data search means 60 and a format conversion means 70, and has a function of providing data libraries 91 and 92 to a plurality of CAD tools 81 and 82.
Each of these components is specifically realized by a computer and its software. The basic function of this device is to generate and manage LSI design component data. That is, the LSI design part data is stored as a database in a design part data area in the storage means 10, and this device generates new LSI design part data based on this database,
It has a function to upgrade SI design parts data.

§2 LSI Design Parts Data Here, before describing the operation of this device, a brief description of what specific LSI design parts data prepared as a database is will be given. FIG. 2 is a diagram showing each stage of a general LSI design work. First, in a function design stage 1, a design is performed in which an LSI to be designed is represented by a combination of several function blocks. In the subsequent logic design stage 2, design is performed in which each functional block is represented by a combination of several logic elements (AND gate, OR gate, inverter, etc.). Further, in the circuit design stage 3, design is performed in which each logic element is represented by a circuit diagram in which a transistor element, a resistance element, a capacitance element, and the like are combined. Then, in the layout design stage 4, a mask pattern corresponding to each element in the circuit diagram is designed. Generally, the design work in each of these stages is performed by using a dedicated CAD tool. This each C
The AD tool has component data necessary for each design work. That is, functional design component data is prepared in the function design stage 1, logical design component data is prepared in the logic design stage 2, circuit design component data is prepared in the circuit design stage 3, and layout design component data is prepared in the layout design stage 4. Is prepared.

FIG. 3 shows some specific examples of these design part data. The component data A is component data used in the logic design stage 2, and in this example, an element formed by connecting three inverter elements I1, I2, and I3 in series forms one component. Actually, there are many components including only one inverter, components including other logic elements such as an AND gate and an OR gate, and components combining these components. Further, even if the components are formed by combining the same logic elements, they are different components having different operation characteristics and sizes. For example, component data A is functionally formed by connecting three inverter elements in series, but the operation characteristics of the component (for example, the delay from when an input signal is applied to when an output signal is obtained) are obtained. The time) and the size (the area occupied on the semiconductor chip) are also determined in advance. Therefore, even a component having the same function as “three inverter elements are connected in series” is a component separate from component data A if the delay time and the occupied area are different. As described above, the “parts data” in the present invention refers to functional information (information indicating that three inverter elements I1, I2, and I3 are connected in series in the part data A) and characteristic information for a target part. This means data including information (delay time and other electrical characteristic information) and structural information (information such as size, shape, and positions of input / output terminals).

The component data B is component data used in the circuit design stage 3, and in this example, two transistors T
An element formed by connecting T1 and T2 in parallel constitutes one component. As components used in the circuit design stage 3, many components including not only such transistors but also resistors and capacitors are prepared. After all, this part data B
In addition to the functional information that the two transistors T1 and T2 are connected in parallel, the characteristic information and the structural information of each transistor are included. On the other hand, the component data C is
This is component data used in the layout design stage 4. In this example, a mask pattern in which the diffusion layer F1 and the polysilicon layer F2 intersect constitutes one component. Again, this component data C also includes the diffusion layer F1 and the polysilicon layer F2.
In addition to the functional information that the mask pattern intersects the characteristic information, characteristic information (such as conductivity in each layer) and structural information (such as the area of each layer) are included.

§3 In the ASIC for interconnecting LSI design component data, it is necessary to design a relatively large-scale circuit in a short time according to the requirements of individual users. It is necessary to provide the user with the LSI design part data as a library. That is, it is necessary to prepare an enormous number of component data for all stages 1 to 4 shown in FIG. In addition, this enormous number of component data have some relation to each other, and one component data is generally generated by synthesizing an element inherent in another component data and an element provided from the outside. It is.

The relationship between the component data will be briefly described with reference to FIG. As described above, various information is inherent in one component data, and only certain information can be extracted as one element. In LSI design part data, generally, functional elements, characteristic elements,
Extraction of structural elements is possible. For example, consider layout design component data D as shown in FIG. The layout design component data expresses a part of the LSI as a set of figures, as shown in component data C of FIG. In the example shown in FIG. 4, from the layout design component data D, the type of element and the connection information of the element are extracted as the functional element d1, and the characteristic value of the element is extracted as the characteristic element d2. The size, shape, position and name of input / output terminals of each figure are extracted as the target element d3. In other words, the layout design component data D
The information inherent in is a functional element d1, a characteristic element d
2, it is decomposed into three elements of structural element d3.

Considering the generation process of the layout design component data D, in the example of FIG. 4, the component data D is generated by combining the element e and the element b1.
Here, the element b1 is a functional element (specifically, a circuit diagram) obtained by decomposing another part, that is, the circuit design part data B ′, and the element e is a design rule (for example, , Spacing between wiring layers, etc.). After all, the layout design component data D is data generated by combining the element b1 obtained by decomposing another component and the element e provided from the outside.

The relationship between the component data will be described with reference to a specific example. For example, the component data A shown in FIG.
If it is attempted to generate circuit design component data corresponding to (logic design component data), one inverter is composed of two transistors.
Are generated in such a manner that component data B '(not shown) are connected in a three-stage series. In this case, the component data B ′ is a functional element a1 inherent in the component data A.
(That is, information that the inverter elements are components connected in series in three stages). Further, in order to generate the layout design component data D corresponding to the component data B ', a functional element b1 included in the component data B' (that is, a circuit diagram showing that a pair of parallel transistors are connected in three stages in series). ) And an externally applied design rule e.

As a result, a large number of LSI design component data are an aggregate having a complicated relationship with each other. FIG.
It is a simple model showing an example of this mutual relation. When the component data A is decomposed, elements a1, a2, and a3 are extracted,
When the component data B is decomposed, elements b1, b2, and b3 are extracted, and when the component data C is decomposed, elements c1 and c2 are extracted. The component data C is generated by combining the element a3 and the element b3, and the component data D
Is generated by synthesizing the element b2 and a design rule e which is an element given from the outside (this model is slightly different from the example of FIG. 4). From the above description, it can be understood that the component data used in each stage shown in FIG. 2 has a complicated relationship with each other.

§4 LSI design parts data generation management machine
Ability Well, here back to FIG. 1 again, the operation of the device according to the present invention. The element extracting means 20 is a means having a function of extracting a specific element included in the desired component data from the desired component data. That is, when the layout design component data D in FIG. 4 is given, a process of extracting the functional element d1, the characteristic element d2, and the structural element d3 from this is performed. Means for performing such processing is known. For example, as a means for extracting the functional element d1, various circuit network extraction software is known.
Various electrical parameter extraction software are known as means for extracting the characteristic element d2, and various graphic operation software are known as means for extracting the structural element d3. On the other hand, the component synthesizing means 30
Is a unit having a function of synthesizing new component data by synthesizing an element inherent in desired component data or an element input from the outside. That is, FIG.
, A process of synthesizing new component data D by synthesizing the component b1 inherent in the component data B ′ and the element e input from the outside. Means for performing such processing are also known. That is, individual LSI design component data is generally generated by combining several elements, and such component data generation processing has conventionally been performed by various software. The expression conversion unit 40 is a unit having a function of generating another element by converting the expression of an element included in desired component data. For example, when an element called an inverter is expressed as logical design part data, it is expressed by a so-called inverter symbol mark in which a triangle is circled. If it is expressed by a transistor and further expressed as layout design component data, it is expressed as a complicated figure pattern.
However, each of these components must be a logic element called an inverter that performs the same function. The expression conversion means 40 is a means for converting the expression of substantially the same parts. The model of FIG. 5 shows an example in which the element x1 is obtained by performing the expression conversion of the element a2. Means for performing such expression conversion processing are also known, and various software have been conventionally used.

The feature of this apparatus is that when the element extraction processing is performed by the element extraction means 20, when the component synthesis processing is performed by the component synthesis means 30, and when the expression conversion processing is performed by the expression conversion means 40, That is, the process of each processing is stored as process data. That is, in FIG.
A design component data area 11 and a process data area 12 are provided in the inside, and each generated component data A,
B, C,... Are stored in the design component data area 11, and process data P1, P2, P
Are stored in the process data area 12. Here, the process data is information indicating a processing process of what kind of component or element has been obtained by what kind of processing. For example, in the example shown in FIG. 4, element extraction processing (disassembly processing) is performed on layout design part data D.
Is performed, the functional element d1, the characteristic element d2,
When the structural element d3 is obtained, information specifying software used for each element extraction processing is stored as process data. For example, information that “the element d1 is obtained as a result of performing a process of extracting a functional element from the component data D using the circuit network extraction software” is recorded as the process data. In the embodiment shown in FIG. 4, information indicating a related element of each element is further included in a part of the process data. For example, regarding the process of extracting the functional element d1, this element d1 is the functional element b of the component data B '.
1 is recorded as process data, and for the process of extracting the structural element d3, information indicating that the element d3 is related to the design rule e is recorded as process data. Has been recorded. Information indicating such related elements can be input by an operator when each process is executed, or can be automatically generated by software for executing each process.

The operation of the apparatus of FIG. 1 for the model shown in FIG. 5 is as follows. First, design part data area 1
1, it is assumed that component data A and B are stored in advance. Here, using the specific software in the element extracting means 20, the component data A is decomposed and the components a1, a
2, a process P1 for extracting the component data B and a process P2 for extracting the components b1, b2, and b3 by using the specific software in the component synthesizing means 30. It is assumed that a process P3 of generating new component data C by combining a3 and element b3 has been executed. In this case, new component data C is added in the design component data area 11, but at the same time, process data P1, P2, and P3 are recorded in the process data area 12. Subsequently, the element extracting means 20
Using the specific software in the above, a process P4 of decomposing the component data C and extracting the elements c1 and c2 is executed,
Furthermore, it is assumed that a process P5 of generating new component data D by synthesizing the elements b2 and c1 and the external element e using specific software in the component synthesizing means 30 is assumed. In this case, new component data D is added in the design component data area 11, and at the same time, process data P4 and P5 are recorded in the process data area 12. Further, when the expression conversion processing for converting the expression of the element a2 to obtain the element x1 by using the specific software in the expression conversion means 40, the process P6 is further performed.
Will be additionally recorded.

When various processes are performed using the respective units in the apparatus shown in FIG. 1, the processing process is sequentially recorded in the process data area 12 as process data. By the way, in order to create an LSI design data sheet, it is only necessary to provide each component data in the design component data area 11, and the process data area 1
The process data in 2 is not directly needed. Therefore, the merit of recording such process data will be described below.

The progress of the semiconductor process is constantly evolving,
The degree of integration of devices formed on a semiconductor wafer is improving year by year. Therefore, each component data is appropriately updated, and so-called version upgrade is performed.
For example, in the case where a technology that can design the spacing between wiring layers to be shorter due to the improvement in insulation is developed, the design rules are updated, and as a result, the layout design component data is upgraded. For example, when the component data C shown in FIG. 3 is upgraded, new component data C in which each figure is reduced by one size
N can be generated. At this time, the component data C and CN are
Comparing each element extracted from each element, the functional element is the same (for example, a mask pattern for an inverter element remains the same even if the design rule is updated even if the design rule is updated). However, characteristic elements (for example, operation time) and structural elements (size, shape, input / output terminal positions) will change. Therefore, it is necessary to update other component data generated based on the characteristic element and the structural element to generate new component data. When such a version upgrade is performed, the process data area 1
2 is extremely effective. That is, when the content of one component or element is upgraded, it can be easily recognized from the process data whether the upgrade affects another component or element. , It is possible to easily perform the version-up process of another component or element that has an influence.

This will be described with reference to the model shown in FIG. Now, consider a case where the contents of the component data A are upgraded and a new component data AN is generated due to some technical progress. In this case, the process data area 1
2, the fact that the component data A has been decomposed into elements a1, a2, and a3 is recorded in the past, and if the process data P3 is read, the elements a3 and The fact that the component data C has been synthesized by b3 is recorded. Therefore,
When the element a3 is upgraded, it can be recognized that the component data C also needs to be upgraded. For example, if the component data A has been upgraded to AN and the element a3 has been upgraded to the element a3n, it is necessary to generate new component data CN by combining the element a3n and the element b3. In other words, because the component data A has been upgraded to AN, the component data C needs to be upgraded to CN. In the device according to the present invention, this version upgrade process can also be easily performed. The reason is that the process data P3 records the past processing process as to which component data C was generated by performing what kind of software and what kind of synthesis processing was performed on the element a3 and the element b3. Therefore, if completely the same processing is performed using the element a3n instead of the element a3, the upgraded part data CN is automatically obtained.

In this way, when the component data C is upgraded to CN, it is possible to easily recognize whether or not the content of the element c1 obtained by performing the process P4 changes. For example, when the element c1 is upgraded to the element c1n, if the process P5 is executed for the element c1n, the element b2, and the design rule e, it is easy to upgrade the component data D to DN. You can do it.

In short, in the process data area 12,
By keeping a record of each executed process, it is possible to automatically recognize which other parts or elements will be affected when a certain part or element is upgraded, and By re-executing the same process as the past process, it is possible to automatically upgrade the affected parts.

§5 Library providing machine for CAD tools
Ability has been described the operation for generating the management functions of LSI design part data in the apparatus shown in FIG. If this function is used, it is possible to easily maintain the latest component data as a database in the design component data area 11 in addition to the existing data. A feature of the present invention is that a data search unit 60 and a format conversion unit 70 are further connected to a part for performing the generation management function of the LSI design part data, and a database prepared in the design part data area 11 On the basis of the above, there is provided a data library for each of a plurality of CADs. Hereinafter, this CA
The function of providing a library to the D tool will be described.

Now, the user enters the first CAD tool 8
Let us consider a case where a specific ASIC design is performed using No. 1. In this case, the user performs an operation of assembling a specific ASIC by using a part that can be used with the first CAD tool among a large number of parts prepared in the design part data area 11. For example, assuming that the first CAD tool 81 is a tool for executing the layout design stage 4 shown in FIG. 2, this tool uses layout design part data. When the user specifies a certain condition, the first CAD tool 81 transmits search information indicating this condition to the data search means 60. The data search means 60, based on the search information,
A part corresponding to the condition is searched from the database in the design part data area 11. When the corresponding component data is retrieved, the component extracting unit 20 extracts necessary component data from the component data, and the extracted component data is provided to the format conversion unit 70. Format conversion means 70
Inside, format information on the first CAD tool 81,
Format information on the second CAD tool 82 is prepared. In the case of the above example, the format conversion means 70 converts the extracted element data into a format compatible with the first CAD tool 81 and provides this to the first CAD tool 81. In this way, the first CAD tool 81 can obtain necessary data in a predetermined format, and can save this as the data library 91.

The function of the format conversion means 70 is to supply data to each CAD tool in a format suitable for each. For example, suppose that the data of a mask pattern as shown in FIG. 6 is extracted as element data by the element extracting means 20 and this data is given to the format converting means 70. In this case, one CAD tool may need all of the data shown in FIG.
The D tool may need only the positions and names of the input / output terminals, as shown in FIG. Further, even if the data has the same contents, the data structure differs depending on each CAD tool. In such a case, the format conversion unit 70 performs a process of converting the data into a format suitable for each CAD tool and supplying the data. As described above, the database in the design component data area 11 is centrally managed in a common format without depending on each CAD tool at all, and is converted into a format suitable for each CAD tool by the format conversion means 70. Data supply is one of the features of the present invention. With such a configuration, even if the component data is updated, it is only necessary to perform the update process on the database in the design component data area 11. Further, even when a new CAD tool is added, a data library for the new CAD tool can be provided only by adding format information on the new CAD tool in the format conversion means 70.

Further, according to this device, the data search means 60 can perform data search using the process data in the process data area 12. For example, consider a case where a user performs a logic design using the second CAD tool 82 and performs a design using various logic gates as components. Here, for convenience of explanation,
The description will be made assuming that each of the component data A to D of the model in FIG. 5 constitutes a component data group including a plurality of component data. For example, element a3 of component data A-1
The component data C-1 is synthesized using -1 and the component data C-2 is synthesized using the element a3-2 of the component data A-2. Here, it is assumed that the user desires to select and use a logic gate having a specific power consumption from the component data group C. In this case, if the elements a3-1, a3-2,... Are elements indicating “power consumption”, the respective component data C-1, C-2,.
, The processes P3-1, P3-2,.
, The elements a3-1, a3-2,... Can be obtained. Therefore, these elements a3-1 and a3-
It is sufficient to search from 2... Those corresponding to the desired power consumption. For example, if the element a3-2 corresponds to a desired power consumption, the component data C
You just have to choose -2. As described above, each component in the design component data area 11 is generated by intertwining elements of other components in a complicated manner, and the generation process is recorded as process data in the process data area 12. ing. Therefore, by referring to the process data, it is possible to easily search for a component having a specific “power consumption”. As described above, when the user inputs a predetermined condition (for example, “power consumption”) as search information, the data search unit 60 refers to the process data in the process data area 12 to search for a part that meets this condition. Is also one of the features of the present invention.

Although the present invention has been described with reference to a simple embodiment, the present invention is not limited to this embodiment but can be implemented in various other modes. For example,
Each unit shown in FIG. 1 may be configured by a single computer, or may be configured by a plurality of computers. Further, a configuration may be adopted in which a part is installed on the semiconductor manufacturer side, another part is set on the user side, and the two are connected via a communication line. Further, the elements themselves extracted by the element extracting means 20 can be stored in the design part data area 11 as one part data.

[0032]

As described above, according to the CAD data library generating apparatus for LSI design according to the present invention,
Since the design part data is prepared as a database, the data required by the CAD tool is searched based on the search information from the CAD tool, and the data is converted into a format suitable for the CAD tool and supplied. Data can be centrally managed. Further, since the process when the database was created is left, when predetermined component data is updated in the future, it is possible to obtain information as to which other component data is affected by the update, The database can be easily updated.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a basic configuration of a data library generation device for a CAD for LSI design according to the present invention.

FIG. 2 is a diagram showing each stage of a general LSI design work.

FIG. 3 is a diagram showing a specific example of general LSI design component data.

FIG. 4 is a diagram illustrating an example of an element extraction process and a component synthesis process for LSI design component data.

FIG. 5 is a diagram showing a simple model for explaining the interrelation of LSI design part data.

FIG. 6 is a diagram showing an example of mask pattern data extracted by the apparatus shown in FIG.

FIG. 7 is a diagram showing an example in which the format of the mask pattern data shown in FIG. 6 is converted.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Function design stage 2 ... Logic design stage 3 ... Circuit design stage 4 ... Layout design stage 10 ... Storage means 11 ... Design part data area 12 ... Process data area 20 ... Element extraction means 30 ... Component synthesis means 40 ... Expression conversion means 50 input means 60 data search means 70 format conversion means 81 first CAD tool 82 second CAD tool 91, 92 data libraries A to D part data F1 polysilicon layer F2 diffusion layer a1 ... a3, b1 to b3, c1 to c2, d1 to d3 ... elements e ... external elements (design rules) I1 to I3 ... inverters T1, T2 ... transistors P1 to P6 ... processing process / process data

────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Yuji Machiya 1-1-1, Ichigaya-Kaga-cho, Shinjuku-ku, Tokyo Dai Nippon Printing Co., Ltd. (56) References Patent 3145778 (JP, B2) Patent 3145779 (JP, B2) Patent 3145780 (JP, B2) (58) Fields investigated (Int. Cl. ⁷ , DB name) H01L 21/82 H01L 27/118 G06F 17/50

Claims (2)

(57) [Claims] 1. A device for generating various parts data library used in the CAD tool for LSI design, the desired part data, thus shown in this part data
Elements that indicate the function of the parts that are
Elements, structural elements that indicate the structure
That the element extracting means for extracting a specific element, by combining the input from the element or outside the element about the desired component data, a component combining means for combining new part data, the synthesized parts A design component data storage unit for storing data; a process data storage unit for storing a process of an extraction process performed by the element extraction unit and a synthesis process performed by the component synthesis unit; A data retrieval unit for retrieving specific data from the data in the design part data storage unit, based on the data, and a format for converting the data retrieved by the data retrieval unit so as to conform to the format of the CAD tool. Inputting data or an instruction to the converting means, the element extracting means and the component synthesizing means; Data library generation device for CAD LSI design, characterized in that it comprises input means, a. 2. The apparatus according to claim 1, wherein the function design part data, the logic design part data, and the circuit design part are provided.
Product data or layout design component data
For the desired part data expressed in data format,
Function indicating the function of the part indicated by the desired part data
Characteristic element, characteristic element showing electrical characteristics, or structure
Data that the desired component data has
To convert to a representation in a data format different from the format
Further provided, the data library generation device for CAD LSI design, characterized in that so as to store the process representation conversion process by the representation conversion unit to process data storage means a representation converting means to generate more separate elements.