JPH0765043A - Layout verifying device - Google Patents

Abstract

PURPOSE:To provide a layout verifying device which can verify the connection state and the size of a surge protecting element based on a layout pattern diagram. CONSTITUTION:A layout verifying device is provided with a means which stores the size of a surge protecting element prepared for each pad as well as the correct connection state between the surge protecting element and its peripheral element as the surge protecting element connection data 11, and a means which extracts the elements connected to the pad, a power supply and a GND out of the net list data 6b produced based on a layout pattern diagram data 3. Furthermore a means is added to extract the element connected to the power supply or the GND as a surge protecting element for each pad among those extracted elements, together with a means which retrieves the peripheral element connected to the extracted surge protecting element, and a means 10 which carries out the comparison and verification of the connection state and the size of the retrieved surge protecting element against the data 11.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a layout verification device, and more particularly to a method for verifying the connection relationship of surge protection elements.

[0002]

2. Description of the Related Art FIG. 4 is a block diagram showing a conventional layout verification apparatus. In the figure, 1 is a means for creating layout pattern diagram data 3 from circuit diagram data 2 and 4a
Is an element recognition means for extracting each element from the circuit diagram data 2,
Reference numeral 5a is a netlist extracting means for creating netlist data 6a based on the elements extracted by the element recognizing means 4a, 4b is an element recognizing means for extracting each element from the layout pattern diagram data 3, and 5b is an element recognizing means. 4b
Netlist data 6b based on the elements extracted by
Is a netlist extraction means for creating. 7 compares the netlist 6a created from the circuit diagram data 2 with the netlist 6b created from the layout pattern diagram data 3 to verify whether or not the layout pattern diagram is drawn according to the circuit diagram. It is a netlist comparison unit that outputs the comparison result to the result display unit 8 and the result list 9.

Next, the operation will be described. Normally, the layout pattern diagram creating means 1 inputs the simulated circuit diagram data 2 by using an editor on the EWS to manually create the layout pattern diagram data. The layout verification device verifies whether or not the layout pattern diagram data 3 is drawn as the circuit diagram data 2. Then, the connection state of the surge protection element for protecting the element breakdown due to a steep surge current or voltage is similarly verified by comparing the circuit diagram data 2 and the layout pattern diagram data 3. First, the element recognition means 4a extracts each element from the circuit diagram data 2,
Based on this, the netlist extracting means 5a creates the netlist data 6a. On the other hand, the element recognition means 4b extracts each element from the layout pattern diagram data 3, and the netlist extraction means 5b creates the netlist data 6b based on the extracted elements. Next, the netlist comparing means 7 creates a netlist 6a created from the circuit diagram data 2 and a netlist 6 created from the layout pattern diagram data 3.
b is compared, and the result is output to the result display means 8 and the result list 9 by treating the different portion as an error.

[0004]

Since the conventional layout verification device is constructed as described above, it is necessary to draw the surge protection element in the circuit diagram data in order to verify the connection relationship of the surge protection element. is there. However, since the surge protection element does not affect the operation in circuit simulation, it is often not drawn in the circuit diagram data,
In that case, there is a problem that the connection relation of the surge protection element cannot be verified.

The present invention has been made to solve the above problems, and an object thereof is to obtain a layout verification apparatus capable of verifying the connection state and size of a surge protection element from a layout pattern diagram.

[0006]

A layout verification apparatus according to the present invention is based on a layout pattern diagram data and a means for holding connection information which is a correct connection relationship between a surge protection element and peripheral elements for each pad. A means for extracting the elements connected to the pad, the power supply and the GND from the created netlist, a means for extracting the element connected to the power supply or the GND among the extracted elements as a surge protection element for each pad, the extraction Means for retrieving peripheral elements connected to the surge protection element, and means for comparing and verifying the connection relationship between each pad and the surge protection element and its peripheral elements extracted for each pad with the above connection information. There is.

Further, there is provided means for detecting whether or not the size of the element extracted as the protection element is equal to or larger than a predetermined value.

[0008]

According to the present invention, the connection relationship between each pad, the surge protection element connected to it, and the peripheral elements extracted from the netlist created from the layout pattern diagram data is separately maintained. It is compared with the correct connection information that exists, and if they do not match, an error occurs.

If the size of the extracted surge protection element is smaller than a predetermined value, it is judged as an error.

[0010]

【Example】

Example 1. An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram 1 showing a portion of a layout verification device for verifying a surge protection element. 10
Is a surge protection element verification means for extracting a surge protection element from the netlist data 6b and performing comparison verification based on the stored surge protection element connection data 11.

Next, the operation will be described with reference to the flowchart of FIG. First, the netlist data 6b created from the layout pattern diagram data 3 is read, and the elements connected to each pad, the power supply, and the GND and the peripheral elements are extracted (S1). Next, among the extracted elements, the one connected to the power supply or the GND is used as a surge protection element to search the connection relation for each pad (S2). The retrieved connection relation is compared with the surge protection element connection data 11 held in advance (S3), and if they do not match (NO in S3), an error result is output (S5), and the process ends. If they match (Y in S3
At the time of ES), it is checked whether the diffusion area or resistance of the diode as the surge protection element is equal to or more than a certain value (S4). If the value is equal to or more than the certain value (YES in S4), the verification is finished as OK. If it is smaller than the fixed value (NO in S4), the result is output as an error (S5) and the verification is completed.

The above operation will be described in detail with reference to an example of the netlist data 6b shown in FIG. For example, since the net number 2 is connected to the pad PADA, the elements dio (0), dio (1) and res (0) are extracted. Further, since the element dio (0) is also connected to the net number 1, it is searched that it is also connected to VCC (power supply). Since the element dio (1) is also connected to the net number 0, it is searched that it is also connected to GND. From the above, the elements dio (0) and dio (1) are used as surge protection elements and the pad PAD
The connection relation between the surge protection element and the peripheral element for A is extracted. Next, the extracted connection relationship is compared and verified with the surge protection element connection data 11. FIG. 4 shows an example of the surge protection element connection data 11, in which four correct connection relationships are stored. It is examined whether or not the extracted connection relation matches any of these four patterns. Since the connection example of FIG. 3 corresponds to FIG. 4A, the connection relationship can be determined to be OK. Further, in each pattern of FIG. 4, the size of the surge protection element can be verified at the same time by holding the diffusion area and resistance value of each diode at the same time and comparing with the size of each element obtained from the netlist. Become. As described above, the connection state and size of the surge protection element can be verified only from the layout pattern diagram data without needing the circuit diagram data.

[0013]

As described above, according to the present invention, the correct connection relations of the surge protection elements are stored, and the connection relations of the surge protection elements extracted based on the net list created from the layout pattern diagram data are stored. Since the connection relation is compared and verified, there is an effect that the connection state of the surge protection element can be verified only from the layout pattern diagram data without the need for the circuit diagram data. Further, since the size of the surge protection element is set in advance together with the connection relationship of the surge protection element and compared with the size of the extracted surge protection element, the size of the surge protection element can also be verified.

[Brief description of drawings]

FIG. 1 is a block diagram showing a layout verification device according to an embodiment of the present invention.

FIG. 2 is a flow chart for explaining the operation of the surge protection element verification means of FIG.

FIG. 3 is a diagram showing an example of a net list created from layout pattern diagram data.

FIG. 4 is a diagram showing a connection example of a surge protection element.

FIG. 5 is a block diagram showing a conventional layout verification device.

[Explanation of symbols]

 1 Layout Pattern Diagram Data Creating Means 2 Circuit Diagram Data 3 Layout Pattern Diagram Data 4b Element Recognition Means 5b Netlist Extraction Means 6b Netlist Data 10 Surge Protective Element Verification Means 11 Surge Protective Element Connection Data

Claims (2)

[Claims] 1. A means for holding connection information which is a correct connection relationship between a surge protection element and peripheral elements for each pad, and a pad, power supply and GND are connected from a netlist created based on layout pattern diagram data. Means for extracting the extracted elements, means for extracting each element of the extracted elements connected to the power supply or GND as a surge protection element for each pad, and peripheral elements connected to the extracted surge protection element. A layout verifying device comprising: means for searching; and means for comparing and verifying the connection relationship between each pad, the surge protection element extracted for the pad, and its peripheral elements, with the connection information. 2. The layout verification apparatus according to claim 1, further comprising means for detecting whether or not the size of the element extracted as the surge protection element is equal to or larger than a predetermined value.