JPH11259544A - Wiring capacity calculation device and method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To calculate the wiring capacity at high speed with high accuracy by dividing an attentional wiring into partial wirings according to its ambient situation and calculating the electrostatic capacity of each partial wiring. SOLUTION: An attentional wiring is divided into partial wirings according to its ambient situation, and the electrostatic capacity of each partial wiring is calculated. In this wiring capacity calculation device, an attentional wiring is divided into two 1st type partial wirings and then into seven 2nd type partial wirings by a wiring dividing device 103. Then a partial wiring capacity calculator 104 calculates the wiring capacity of each 2nd type partial wiring based on the layout information on the 2nd type partial wirings which are received from the device 103 and then outputs its calculated results to a wiring capacity totalizer 105. When the capacity of all 2nd type partial wirings are calculated, the totalizer 105 totalizes the capacities of the 2nd type partial wirings and then calculates the capacity of the attentional wiring.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wiring capacitance calculating device and a wiring capacitance calculating method for calculating a capacitance of a wiring of a semiconductor integrated circuit.

[0002]

2. Description of the Related Art In designing a semiconductor integrated circuit, a capacitance to ground (hereinafter referred to as a wiring capacitance) may be calculated in order to know a propagation delay time of each wiring.

[0003] As a wiring capacitance calculating device which is a device for calculating a wiring capacitance, a detailed technique is described in, for example, Japanese Patent Application Laid-Open No. 5-181926. This Japanese Unexamined Patent Publication No.
In the conventional wiring capacitance calculation device disclosed in Japanese Patent Application Laid-Open No. 181926, a wiring whose calculated wiring capacitance is calculated (hereinafter referred to as a target wiring) is divided into predetermined lengths (hereinafter referred to as predetermined lengths).
For each wiring of a predetermined length, the surrounding state (here, the presence or absence of an adjacent wiring or an intersecting wiring) is coded.
Then, based on a coded correspondence table showing the relationship between the surrounding situation and the wiring capacity, the wiring capacity is obtained for each wiring of a predetermined length, and the sum is calculated to calculate the wiring capacity of the wiring of interest.

[0004]

The wiring capacitance is affected by the distance between adjacent wirings (hereinafter, referred to as adjacent wirings) and the inter-interval of the intersecting wirings (hereinafter, referred to as crossing wirings).
However, in the above-described conventional wiring capacity calculating apparatus, the wiring capacity is calculated by performing the classification based only on the presence or absence of the adjacent wiring or the cross wiring. Therefore, there is a problem that the calculation accuracy of the wiring capacitance is low because the distance between the adjacent wirings and the interval between the crossing wirings are not taken into consideration.

In the conventional wiring capacitance calculating apparatus, a target wiring is divided into predetermined lengths, and a wiring capacitance is obtained for each wiring having a predetermined length. Accordingly, even for a target wiring in which the same surrounding state continues for a plurality of wirings of a predetermined length, the same processing is repeated for each wiring of a predetermined length to calculate the wiring capacitance, and the processing time is reduced. There were also problems.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems of the prior art, and a wiring capacitance calculating apparatus and a wiring capacitance calculating apparatus capable of calculating wiring capacitance with high accuracy and at high speed. It is an object to provide a capacity calculation method.

[0007]

According to another aspect of the present invention, there is provided a wiring capacitance calculating apparatus for calculating a capacitance of a wiring, wherein the capacitance is a capacitance per unit length. A coefficient calculating device that calculates a coefficient in accordance with a plurality of surrounding situations classified according to a distance to an adjacent wiring and an intersection interval of an intersecting wiring; and a capacitance coefficient calculated by the capacitance coefficient calculating device. A capacitance coefficient table storage unit that stores a table corresponding to the surrounding situation, a wiring dividing apparatus that divides the target wiring, which is the calculated wiring of the capacitance, according to the surrounding situation, The capacitance coefficient of each of the partial wirings is determined by referring to the table, and the capacitance of each of the partial wirings is calculated by multiplying the capacitance coefficient by the wiring length. A feeder line capacity calculating device, and the total capacitance of each partial wiring calculated by the partial capacity calculating device, and has a wiring capacitance sum device for calculating the electrostatic capacitance of the target wiring.

At this time, the wiring dividing apparatus divides the wiring of interest into two when the wiring of interest is not in the middle layer of the substrate, and splits the wiring of wiring when the wiring of interest is in the middle layer of the substrate. In the width direction and 2 in the thickness direction.
The wiring may be divided, and the length of each of the divided wirings may be further divided at a portion facing an end of an adjacent wiring and a portion intersecting with another wiring, and may be further divided at an end of an adjacent wiring. The extension distance of the wiring corresponding to the capacitance existing between
An elongation distance calculation device that calculates each corresponding to a plurality of situations classified by the distance to the wiring and the wiring layer, and each elongation distance calculated by the elongation distance calculation device is stored as a table corresponding to the situation. An extension distance table storage unit for determining the extension distance of the wiring adjacent to the target wiring by referring to the table, and extending the layout information of the wiring by the extension distance. It may be.

Further, a wiring capacitance calculating method according to the present invention is a wiring capacitance calculating method for calculating a capacitance of a wiring, wherein a capacitance coefficient, which is a capacitance per unit length, is calculated with respect to an adjacent wiring. Capacitance coefficient calculation steps respectively calculated according to a plurality of surrounding situations classified according to distances and intersecting intervals of intersecting wirings, and each capacity coefficient calculated in the capacity coefficient calculating step is stored as a table corresponding to the surrounding situation. A capacitance coefficient table storing step, a wiring division step of dividing the wiring of interest, which is the calculated wiring of the capacitance, according to the surrounding situation, and a capacitance coefficient of a partial wiring that is the wiring divided in the wiring division step. A partial wiring capacitance calculation step for calculating the capacitance of each of the partial wirings by calculating the capacitance by multiplying the capacitance coefficient by the wiring length. And up to a total of the capacitances of each partial wiring calculated by the partial wiring capacitance calculation step, a wiring capacitance sum calculating a capacitance of the target wiring,
It is a method having.

At this time, in the wiring dividing step, if the wiring of interest is not in the intermediate layer of the substrate, the wiring of interest is divided into two in the width direction. If the wiring of interest is in the intermediate layer of the substrate, the wiring of interest is divided. Is divided into two parts in the width direction and two parts in the thickness direction, and the length of each divided wiring is further divided into a part facing an end of an adjacent wiring and a part intersecting with another wiring. The extension distance of the wiring corresponding to the capacitance existing between the end of the adjacent wiring and the distance between the wiring and the wiring layer may correspond to a plurality of situations classified according to the distance and the wiring layer. An extension distance calculation step to calculate, an extension distance table storing step of storing each extension distance calculated in the extension distance calculation step as a table corresponding to the situation, and an extension distance of a wiring adjacent to the wiring of interest. Determined with reference to the serial table, the adjacent wire extension step of extending the information of the layout of the wiring by 該伸 long distance component may further have a.

In the wiring capacitance calculating apparatus and the wiring capacitance calculating method configured as described above, the target wiring is divided according to the surrounding situation, and the capacitance is calculated for each of the divided partial wirings. Therefore, it is not necessary to calculate the capacitance for each wiring having a predetermined length, unlike the related art, so that the calculation of the capacitance can be performed efficiently.

Further, a capacitance coefficient, which is a capacitance per unit length, is calculated for each of a plurality of surrounding situations classified according to a distance between adjacent wirings and an intersecting interval of intersecting wirings. By storing the capacitance coefficient as a table corresponding to the surrounding situation, calculating the capacitance coefficient of the partial wiring by referring to the table, and multiplying the obtained capacitance coefficient by the wiring length to calculate the capacitance of the partial wiring, The capacitance of the wiring can be calculated in consideration of the distance between the adjacent wiring and the intersection distance of the crossing wiring.

Further, the extension distance of the wiring corresponding to the capacitance existing between the end of the adjacent wiring and the distance between the adjacent wiring and a plurality of situations classified according to the wiring layer is respectively determined. Calculate, store each calculated extension distance as a table corresponding to the situation, obtain the extension distance of the wiring adjacent to the target wiring by referring to the table, and extend the layout information of the adjacent wiring by the extension distance. so,
The wiring capacitance of the target wiring can be obtained in consideration of the influence of the end of the adjacent wiring.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be described with reference to the drawings.

(First Embodiment) FIG. 1 is a block diagram showing a configuration of a first embodiment of a wiring capacitance calculating apparatus according to the present invention.

Referring to FIG. 1, an apparatus for calculating a wiring capacity according to the present embodiment receives an information required for calculating a wiring capacity and outputs necessary information to each apparatus described later; And a capacitance coefficient calculating device 102 that calculates a capacitance coefficient corresponding to a plurality of surrounding situations classified by a distance from an adjacent wiring and an intersection interval of an intersection wiring based on the information received from Storage device 107 having a capacity coefficient table storage unit 108 for storing the respective capacity coefficients as a table (capacity coefficient table) corresponding to the surrounding situation.
And a wiring dividing device 103 that divides the wiring of interest according to the surrounding situation, and a wiring capacity of each wiring divided by the wiring dividing device 103 based on the capacitance coefficient and the wiring length stored in the capacitance coefficient table storage unit 108. A partial wiring capacity calculating device 104 for calculating, a wiring capacity totaling device 105 for summing the wiring capacities calculated by the partial capacity calculating device 104 to calculate the wiring capacity of the target wiring, and an output device for outputting a calculation result of the wiring capacity 106.

In such a configuration, the operation of the wiring capacitance calculating apparatus of the present embodiment will be described with reference to FIG.
This will be described with reference to FIG.

FIG. 2 is a flowchart showing a processing procedure of the wiring capacitance calculating apparatus shown in FIG. Note that the processing of step 201 described below is performed by the input device 101, the processing of steps 202 and 203 is performed by the capacitance coefficient calculator 102, the processing of step 204 is performed by the wiring dividing apparatus 103, and the processing of step 205 is performed by the partial wiring capacitance calculation. In the device 104, the processing of steps 206 and 207 is executed by the wiring capacity totaling apparatus 105, and the processing of step 208 is executed by the output device 106.

In FIG. 2, when a designer of a semiconductor integrated circuit inputs device information (information such as a substance constituting a semiconductor integrated circuit and a shape of a wiring cross section), an input device 101 inputs the device information. Is output to the capacity coefficient calculating device 102. Further, when layout information (wiring route information of each wiring) is input by the designer, the input device 101 converts the input layout information into the wiring dividing device 1.
03 (Step 201).

The capacity coefficient calculating device 102 includes the input device 10
Based on the device information received from No. 1, a capacitance coefficient (wiring capacity per unit length) is calculated using a device simulator or the like (step 2).
02), the calculated capacity coefficients are stored in the capacity coefficient table storage unit 108 (step 203). The capacity coefficient is, for example, a capacity coefficient table 3 as shown in FIG.
01, and is configured so that the capacitance coefficient can be obtained from the distance to the adjacent wiring and the crossing interval of the crossing wiring (C11 to C15, C21 to C25, C31 to C31 in FIG. 3).
C35, C41 to C45, and C51 to C55 each indicate a capacity coefficient. ). The type of the surrounding situation (combination of the distance to the adjacent wiring and the crossing interval of the crossing wiring) can be arbitrarily determined by the designer. The capacity coefficient table 301 can be created for each wiring layer.

The processing up to step 203 described above is a preparation stage for calculating the wiring capacity, and the wiring capacity of each wiring is calculated by performing the processing from step 204 described below.

First, the wiring dividing device 103 divides a target wiring according to the following procedure (step 204). The wiring dividing device 103 first divides the target wiring 401 into two parts in the width direction along the center line in the longitudinal direction, as shown in FIG. When the wiring of interest is in the middle layer of the substrate as shown in FIG. 5, they are further divided into two in the thickness direction. Therefore, the target wiring 5 in the intermediate layer of the substrate
01 is finally divided into four parts. Note that the intermediate layer of the substrate is defined by upper and lower wiring layers (upper wiring layer 505, lower wiring layer 50).
6) means a wiring layer. For example, in the case of a semiconductor integrated circuit using a three-layer substrate, the second layer (the second wiring layer from the bottom) corresponds to an intermediate layer. Each of the two or four divided wires is hereinafter referred to as a first type partial wire.

Subsequently, the wiring dividing device 103 further divides the first type partial wiring according to the surrounding situation. At this time the first
The seed partial wiring is divided into a part facing an end of an adjacent wiring and a part crossing another wiring. When dividing the type 1 partial wiring, it is not necessary to consider all the wirings surrounding the type 1 partial wiring, but only the wiring described below.

First, when the target wiring is located on a layer other than the intermediate layer of the substrate, the first type partial wiring in the left half of the target wiring is located on the left side of the target wiring and within a predetermined distance from the target wiring. , And all the intersecting wires that intersect the wire of interest. In the first type partial wiring in the right half of the target wiring, adjacent wirings existing on the right side of the target wiring and within a predetermined distance from the target wiring and all cross wirings intersecting with the target wiring are considered.

On the other hand, when the target wiring is in the middle layer of the substrate, the first type partial wiring in the upper left half of the target wiring is located on the left side of the target wiring and within a predetermined distance from the target wiring. In addition, all the intersecting wirings existing in the wiring layer above the wiring layer in which the noticed wiring exists and intersecting with the noticed wiring are considered.

In the first type partial wiring in the upper right half of the wiring of interest, the adjacent wiring existing on the right side of the wiring of interest and within a predetermined distance from the wiring of interest and the wiring layer on which the wiring of interest exists All crossing wirings existing in the wiring layer and intersecting with the target wiring are considered.

Further, in the first type partial wiring in the lower left half of the wiring of interest, the adjacent wiring existing on the left side of the wiring of interest and within a predetermined distance from the wiring of interest and the wiring below the wiring layer in which the wiring of interest exists All crossing wirings existing in the wiring layer and intersecting with the target wiring are considered.

In the first type partial wiring in the lower right half of the wiring of interest, the adjacent wiring existing to the right of the wiring of interest and within a predetermined distance from the wiring of interest and the wiring layer below the wiring layer where the wiring of interest exists All the intersecting wirings existing in the wiring layer and intersecting with the target wiring are considered.

The respective wirings obtained by further dividing the first type partial wiring in this manner are hereinafter referred to as second type partial wirings. The wiring dividing device 103 outputs the layout information of the target wiring divided into the second type partial wirings to the partial wiring capacitance calculating device 104.

Next, the partial wiring capacitance calculating device 104 calculates the wiring capacitance of the second type partial wiring based on the layout information of the second type partial wiring received from the wiring dividing device 103, and calculates the wiring result. The data is output to the total capacity device 104 (step 205). At this time, the calculation procedure of the wiring capacitance of the second type partial wiring is as follows.

First, the surrounding state of the noted type II partial wiring (hereinafter, referred to as the noted partial wiring) is determined based on the layout information received from the wiring dividing device 103. Here, the surrounding situation is the distance between the adjacent wiring and the intersection interval of the cross wiring. For example, in the situation around the noticed partial wiring (hatched portion in the figure) 611 shown in FIG. 6, the distance from the adjacent wiring 608 is 1 μm, and the intersection between the two cross wirings 609 and 610 is 2 μm.

Next, the capacitance coefficient corresponding to the surrounding state of the noticed partial wiring 611 is shown in the capacitance coefficient table 301 shown in FIG.
Ask for. When the capacitance coefficient table 301 is referred to and there is no corresponding value in the distance to the adjacent wiring 608 or the intersection interval between the cross wirings 609 and 610 (for example, referring to the capacitance coefficient table shown in FIG. When a capacitance coefficient is obtained when the distance from the wiring 608 is 1.5 μm), appropriate interpolation processing is performed. By multiplying the capacitance coefficient obtained as described above by the length of the target partial wiring, the wiring capacitance of the target partial wiring 611 is calculated.

Next, the wiring capacity totaling device 105 sums the wiring capacities of the respective second type partial wirings calculated by the partial wiring capacity calculating device 104 (step 206).

Finally, it is determined whether or not the wiring capacities of all the wirings have been calculated (step 207). If the wiring capacities of all the wirings have been calculated, the process proceeds to step 208 to calculate by the output device 208. Output the result. If the calculation of the wiring capacities of all the wirings has not been completed, the process returns to the step 204 and the processes of the steps 204 to 207 are repeated.

As described above, according to the wiring capacitance calculating apparatus of the present embodiment, the wiring of interest is divided according to the surrounding conditions, so that the capacitance is calculated for each wiring of a predetermined length as in the prior art. Therefore, the calculation of the capacitance can be performed efficiently. Therefore, the wiring capacitance can be calculated at high speed. Further, since the wiring capacitance can be calculated in consideration of the distance between the adjacent wiring and the intersection interval of the crossing wiring, the wiring capacitance can be calculated with high accuracy.

Next, the operation of the wiring capacitance calculating apparatus of this embodiment will be described using a specific wiring example. In the following, a case will be described in which the wiring capacitance of the wiring of interest 701 shown in FIG. 7 is obtained. The capacity coefficient is calculated in advance by the capacity coefficient calculation device 102 and is stored in the capacity coefficient table storage unit 108.

First, FIG.
8 is divided into two first-type partial wirings (a first first-type partial wiring 801 and a second first-type partial wiring 802) as shown in FIG. 8, and then shown in FIG. Like seven
It is divided into two second type partial wirings (first second type partial wiring 901 to seventh first type partial wiring 907).

Next, the wiring capacitance of each of the second type partial wirings is calculated by the partial wiring capacitance calculating device 104.
For example, the third type partial wiring 903 (the hatched portion in the drawing) shown in FIG. 9 has the capacitance shown in FIG. 3 because the distance between the adjacent wiring is 1 μm and the crossing distance between the crossing wirings is 2 μm. A capacity coefficient C12 is obtained from the coefficient table 301. Also,
Since the wiring length of the third type II partial wiring 713 is 2 μm, the wiring capacitance is C12 × 2 [μm]. Similarly, the wiring capacitances of the other second type partial wirings are obtained. When the wiring capacities of all the second type partial wirings are obtained,
The wiring capacity of each of the second type partial wirings is summed by the wiring capacity totaling device 105 to calculate the wiring capacity of the wiring of interest 701.

(Second Embodiment) Next, a second embodiment of the wiring capacitance calculating apparatus of the present invention will be described with reference to the drawings. It should be noted that the wiring capacitance calculating device of the present embodiment is the same as the first embodiment shown in FIG.
This is a configuration in which an extension distance calculation device and an adjacent wiring extension device are added to the wiring capacity calculation device of the embodiment, and an extension distance table storage unit is added to the storage device.

FIG. 10 shows a second example of the wiring capacitance calculating apparatus according to the present invention.
FIG. 3 is a block diagram illustrating a configuration of an example.

In FIG. 10, the wiring capacity calculating apparatus of the present embodiment receives an information necessary for calculating a wiring capacity and outputs necessary information to each of the devices described later, and an input device 1001. And a capacity coefficient calculator 1002 for calculating a capacity coefficient corresponding to a plurality of surrounding situations classified according to a distance to an adjacent wiring and an intersection interval of an intersection wiring based on information received from the input device 1001. Based on a plurality of situations classified according to the distance to the adjacent wiring and the wiring layer, the extension distance is calculated based on the distance between the adjacent wiring and the wiring layer, based on the extension distance of the adjacent wiring corresponding to the capacitance existing between the end of the adjacent wiring. A distance calculation device 1009 and a capacity coefficient table storage unit 100 for storing the capacity coefficient calculated by the capacity coefficient calculation device 1002
8, and an extension distance table storage unit 101 that stores the extension distance of the adjacent wiring calculated by the extension distance calculation device 1009.
1 and the extension distance between the target wiring and the adjacent wiring are obtained by referring to the extension distance table stored in the extension distance table storage unit 1011, and the layout information of the adjacent wiring is extended by the extension distance. Wiring extender 1
010, a layout dividing device 1003 that receives the layout information output from the adjacent wiring extending device 1010, and divides the wiring of interest according to the surrounding situation.
A partial wiring capacity calculation device 1004 that calculates the wiring capacity of each wiring divided by 3 from the capacity coefficient and the wiring length recorded in the capacity coefficient table storage unit 1008;
It is composed of a wiring capacitance totaling device 1005 that totals the wiring capacitances calculated by the partial capacitance calculating device 1004 to calculate the wiring capacitance of the wiring of interest, and an output device 1006 that outputs the calculation result of the wiring capacitance.

As shown in FIG. 11, there is a wiring capacitance C between the target wiring 1101 and the end of the adjacent wiring 1102, and the closer the distance between the target wiring 1101 and the adjacent wiring 1102 is, the larger this wiring capacitance C becomes. Becomes larger. The extension distance calculating apparatus 1009 replaces the wiring capacitance C between the end of the adjacent wiring 1102 and the wiring of interest 1101 with an adjacent wiring equivalent thereto (equivalent adjacent wiring 1201) as shown in FIG. The extension distance is calculated and stored in the extension distance table storage unit 1011. When calculating the extension distance, a device simulator or the like is used.

The adjacent wire extension device 1010 refers to the extension distance table storage unit 1011 and stores layout information of the adjacent wires extended from the actual wires in the wire dividing device 1003.
Output to

In such a configuration, the operation of the wiring capacitance calculating apparatus of the present embodiment will be described next with reference to FIG. 10 and FIG.

FIG. 13 is a flowchart showing a processing procedure of the wiring capacitance calculating device shown in FIG. In addition, the capacitance coefficient calculating device 10 included in the wiring capacitance calculating device of the present embodiment.
02, wiring dividing device 1003, partial wiring capacitance calculating device 1
004, total wiring capacity device 1005, and output device 10
Operation 06 is the same as in the first embodiment.
Detailed description is omitted.

In FIG. 13, first, when device information is input to the wiring capacitance calculating device by the designer of the semiconductor integrated circuit, the input device 1001 transmits the received device information to the capacitance coefficient calculating device 1002 and the extension distance calculating device. 1009 respectively. When the designer of the semiconductor integrated circuit inputs the layout design information to the wiring capacitance calculating device, the input device 1001 outputs the received layout information to the adjacent wiring extending device 1010 (step 1301).

The capacity coefficient detecting device 1002 is the input device 1
Based on the device information received from 001, a capacity coefficient corresponding to the surrounding situation is calculated (step 130).
2) The respective capacity coefficients calculated in step 1302 are stored in the capacity coefficient table storage unit 1008 (step 1303).

The extension distance calculation apparatus 1009 uses a device simulator or the like to calculate the wiring capacitance C with the end of the adjacent wiring.
Is calculated, and the elongation distance of the adjacent wiring equivalent thereto is calculated (step 1304).
3 (step 1305). The extension distance is, for example, as shown in FIG.
01, and the extension distance is obtained from the distance between the wiring layer where the target wiring exists and the adjacent wiring.

Next, the adjoining wiring extension apparatus 1010 that has received the layout information sets the extension distance table storage unit 101
With reference to the extension distance stored in No. 1, the layout information of the adjacent wiring extended by the obtained extension distance is output to the wiring dividing device 1003. The other layout information is output to the wiring division device 1003 without any change (step 1306).

Thereafter, as in the first embodiment, the wiring of interest is divided by the wiring dividing device 1003 (step 130).
7) The wiring capacitance of the second type partial wiring is calculated by the partial wiring capacitance calculation device 1004 (step 130).
8). Further, the wiring capacity of the target wiring is calculated by adding the wiring capacities of the second type partial wirings by the wiring capacity totaling device 1005 (step 1309). Then, it is determined whether or not the wiring capacities of all the wirings have been calculated (step 131).
0), when the wiring capacities of all the wirings have been calculated, the process proceeds to step 1311 and the output device 1006 outputs the calculation results. If the calculation of the wiring capacities of all the wirings has not been completed, the process returns to the step 1306 to repeat the processing of the steps 1306 to 1310.

As described above, according to the wiring capacitance calculating apparatus of the present embodiment, in addition to the effect of the wiring capacitance calculating apparatus of the first embodiment, the influence of the end of the adjacent wiring on the target wiring is also considered. Since the wiring capacitance of the wiring of interest can be obtained in consideration of the above, a more accurate calculation result of the wiring capacitance can be obtained.

Next, the operation of the wiring capacitance calculating apparatus of this embodiment will be described using a specific wiring example. In the following, a case will be described in which the wiring capacitance of the noticed partial wiring 1501 (hatched portion in the drawing) existing in the third layer shown in FIG. 15 is obtained. The capacity coefficient is determined in advance by the capacity coefficient calculation device 10.
02, and is calculated by the capacity coefficient table storage unit 1008.
Is stored. The extension distance is also calculated in advance by the extension distance calculation device 1009,
It is assumed that it is stored in the extension distance table storage unit 1011.

First, the extension distance calculation device 1009 calculates the extension distance of the adjacent wiring based on the layout information received from the input device 1001, and outputs the extended layout information of the adjacent wiring to the wiring division device 1003. The extension distance of the adjacent wiring is shown in the extension distance table 140 shown in FIG.
Determine with reference to 1.

Here, as shown in FIG. 15, since the distance between the noticed partial wiring 1501 and the adjacent wiring 1502 is 1 μm, the extension distance is D31 as shown in the extension distance table 1401. Therefore, as shown in FIG. 16, the adjacent wiring 1502 is output to the wiring dividing device 1003 as layout information in a shape extended by D31.

Thereafter, the processing executed by the wiring dividing device 1003, the partial wiring capacitance calculating device 1004, the wiring capacitance totaling device 1005, and the output device 1006 is the same as that of the first embodiment, and the description thereof will be omitted.

[0056]

Since the present invention is configured as described above, the following effects can be obtained.

Since the wiring of interest is divided according to the surrounding conditions and the capacitance is calculated for each of the divided partial wirings, it is not necessary to calculate the capacitance for each wiring of a predetermined length as in the prior art. The calculation of the capacitance can be performed efficiently. Therefore, the calculation of the capacitance can be performed at high speed.

The capacitance coefficient, which is the capacitance per unit length, is calculated for each of a plurality of surrounding situations classified by the distance to the adjacent wiring and the intersection interval of the intersecting wiring. Each capacitance coefficient calculated by the device is stored as a table corresponding to the surrounding situation, the capacitance coefficient of the partial wiring is obtained by referring to the table, and the obtained capacitance coefficient is multiplied by the wiring length to obtain the capacitance of the partial wiring. By calculating, the capacitance of the wiring can be calculated in consideration of the distance between the adjacent wiring and the intersection interval of the crossing wiring, so that the calculation of the capacitance can be performed with high accuracy.

Further, the extension distance of the wiring corresponding to the capacitance existing between the end of the adjacent wiring and the distance between the adjacent wiring and the plurality of situations classified by the wiring layer is respectively determined. Calculate, store each calculated extension distance as a table corresponding to the situation, obtain the extension distance of the wiring adjacent to the target wiring by referring to the table, and extend the layout information of the adjacent wiring by the extension distance. so,
Since the wiring capacitance of the wiring of interest can be obtained in consideration of the influence of the end of the adjacent wiring, the calculation of the capacitance can be performed with higher accuracy.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a first embodiment of a wiring capacitance calculating device according to the present invention.

FIG. 2 is a flowchart illustrating a processing procedure of the wiring capacitance calculation device illustrated in FIG. 1;

FIG. 3 is a table diagram showing a configuration example of a capacity coefficient table stored in a capacity coefficient table storage unit shown in FIG. 1;

FIG. 4 is a diagram illustrating a process of the wiring dividing device illustrated in FIG. 1, and is a schematic diagram illustrating a wiring dividing method when a target wiring is not in an intermediate layer.

FIG. 5 is a diagram showing a process of the wiring dividing device shown in FIG. 1, and is a schematic diagram showing a wiring dividing method when a target wiring is present in an intermediate layer.

FIG. 6 is a schematic diagram showing an example of a situation around a noticed partial wiring.

FIG. 7 is a schematic diagram showing a specific example of a target wiring for calculating a wiring capacitance by the wiring dividing device shown in FIG. 1;

8 is a schematic diagram illustrating an example of a process performed by the wiring dividing device on the wiring of interest illustrated in FIG. 7;

9 is a schematic diagram illustrating an example of a process performed by the wiring division device and the partial wiring capacitance calculation device for the wiring of interest illustrated in FIG. 7;

FIG. 10 is a block diagram showing a configuration of a second embodiment of the wiring capacitance calculation device of the present invention.

11 is a schematic diagram illustrating a state of a wiring capacitance existing between a noticed wiring and an end of an adjacent wiring to be considered in the wiring capacitance calculating device illustrated in FIG. 10;

FIG. 12 is a schematic diagram showing processing contents of the wiring capacitance calculating device shown in FIG.

FIG. 13 is a flowchart illustrating a processing procedure of the wiring capacitance calculation device illustrated in FIG. 10;

FIG. 14 is a table diagram showing a configuration example of an extension distance table stored in an extension distance table storage unit shown in FIG.

FIG. 15 is a schematic diagram showing a specific example of a target partial wiring for calculating a wiring capacitance by the wiring dividing device shown in FIG. 10;

FIG. 16 is a schematic diagram illustrating an example of a process performed by the adjacent wiring extending device for the noticed partial wiring illustrated in FIG. 15;

[Explanation of symbols]

 101, 1001 Input device 102, 1002 Capacity coefficient calculating device 103, 1003 Wiring dividing device 104, 1004 Partial wiring capacity calculating device 105, 1005 Wiring capacity total device 106, 1006 Output device 107, 1007 Storage device 108, 1008 Capacity coefficient table storage Part 301 Capacitance coefficient table 401, 501, 701, 1101 Target wiring 505 Upper wiring layer 506 Lower wiring layer 608, 1102, 1502 Adjacent wiring 609, 610 Cross wiring 611 Target partial wiring 801 First type 1 partial wiring 802 First 2nd type 1 partial wiring 901 1st 2nd type partial wiring 902 2nd 2nd type partial wiring 903 3rd 2nd type partial wiring 904 4th 2nd type partial wiring 905 5th 2nd type Partial wiring 906 Sixth second kind partial wiring 907 Seventh second kind part Wiring 1009 extended distance calculating apparatus 1010 adjacent wire extension device 1011 extended distance table storing unit 1201 equivalent adjacent wire 1401 extended distance table 1501 target portion wirings

Claims (6)

[Claims] 1. A wiring capacitance calculating device for calculating a capacitance of a wiring, wherein a capacitance coefficient, which is a capacitance per unit length, is classified according to a distance between adjacent wirings and an intersecting interval of intersecting wirings. A capacity coefficient calculating device that calculates each of the capacity factors corresponding to the plurality of surrounding conditions, a capacity coefficient table storage unit that stores each capacity coefficient calculated by the capacity coefficient calculating device as a table corresponding to the surrounding conditions, A wiring dividing device that divides the target wiring that is the calculated wiring of the capacitance according to the surrounding situation, and obtains the capacitance coefficient of the partial wiring that is the wiring divided by the wiring dividing device with reference to the table,
A partial wiring capacitance calculating device for calculating the capacitance of each of the partial wirings by multiplying the capacitance coefficient by a wiring length; and a capacitance of each partial wiring calculated by the partial capacitance calculating device, and A wiring capacitance calculating device comprising: a wiring capacitance total device for calculating a capacitance of a wiring. 2. The wiring dividing device according to claim 1, wherein the wiring of interest is divided into two in the width direction when the wiring of interest is not in an intermediate layer of the substrate, and the wiring of interest is divided when the wiring of interest is in an intermediate layer of the substrate. The wiring is divided into two parts in the width direction and two parts in the thickness direction, and the length of each divided wiring is further divided into a part facing an end of an adjacent wiring and a part intersecting with another wiring. The wiring capacity calculation device according to claim 1. 3. An extension distance of the wiring corresponding to a capacitance existing between an end of an adjacent wiring and a distance between the wiring and a plurality of situations classified by a wiring layer. An elongation distance calculation device to calculate, an elongation distance table storage unit that stores each elongation distance calculated by the elongation distance calculation device as a table corresponding to the situation, and an elongation distance of a wiring adjacent to the wiring of interest. 3. The wiring capacity calculating device according to claim 1, further comprising: an adjacent wiring extending device that obtains the layout information of the wiring by the extension distance, obtained by referring to a table. 4. A wiring capacitance calculating method for calculating a capacitance of a wiring, wherein a capacitance coefficient, which is a capacitance per unit length, is determined by a distance between an adjacent wiring and an intersection interval of the intersecting wiring. A capacity coefficient calculating step of calculating each of the plurality of classified surrounding conditions, and a capacity coefficient table storing step of storing each of the capacity coefficients calculated in the capacity coefficient calculating step as a table corresponding to the surrounding conditions; A wiring dividing step of dividing the wiring of interest, which is a calculated wiring of the capacitance, according to the surrounding condition; and obtaining a capacitance coefficient of a partial wiring, which is the wiring divided in the wiring dividing step, by referring to the table, A step of calculating the capacitance of each of the partial wirings by multiplying the capacitance coefficient by a wiring length; and a step of calculating the partial wiring capacitance. Tsu summing the capacitance of each partial wiring calculated in flops, wiring capacity calculating method having a wiring capacitance sum calculating a capacitance of the target wiring. 5. In the wiring dividing step, if the wiring of interest is not in the middle layer of the substrate, the wiring of interest is divided into two in the width direction. If the wiring of interest is in the middle layer of the substrate, the wiring of interest is divided. The wiring is divided into two parts in the width direction and two parts in the thickness direction, and the length of each divided wiring is further divided into a part facing an end of an adjacent wiring and a part intersecting with another wiring. The method according to claim 4. 6. An extension distance of an interconnect corresponding to a capacitance existing between an end portion of an adjacent interconnect and an extension distance of the interconnect corresponding to a plurality of situations classified by a distance from the interconnect and an interconnect layer. Elongation distance calculation step to calculate, and each elongation distance calculated in the elongation distance calculation step,
An extension distance table storing step of storing the table as a table corresponding to the situation; determining an extension distance of the wiring adjacent to the wiring of interest with reference to the table; 6. The wiring capacitance calculating method according to claim 4, further comprising a wiring extending step.