JPH1011471A - Analog characteristic data generating method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To generate analog characteristic data used for circuit evaluation in a short time. SOLUTION: Command data 2 are generated which include device information on a maker name, an article number, etc., specifying a device to be analyzed, analytic conditions such as temperature and a source voltage, the electronic constant of the device, and information on an internal buffer. An analog characteristic data generating program 1 reads the command data 2 out and generates input data 3 for a circuit simulator. The input data 3 are supplied to the simulator 4, which performs circuit simulation automatically and repeatedly under the analytic condition instructed with the input data 3 by using a transistor model 5 based upon the input data 3. A circuit simulator result 6 is passed to the analog characteristic data generating program 1 to generate analog characteristic data 7.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an IC used for performing layout simulation of a printed circuit board or the like.
The present invention relates to a method for creating analog characteristic data of devices such as (integrated circuits) and LSIs (large-scale integrated circuits).

[0002]

2. Description of the Related Art When performing a layout simulation on a printed circuit board, an analysis is usually performed using an analog operation model (behavior model) of a device to be analyzed. In order to create this operation model, analog characteristic data in input, output, and input / output buffers of the device is required. The analog characteristic data is a data format of each analog characteristic in each buffer of the device. The analog characteristic data includes a manufacturer's name, an IC name, an electrical constant of a package, a pin arrangement, a rise time, and the like. Response speed information and the voltage-current characteristics (V-
I characteristic) is described. An operation model is created based on the analog characteristic data, and a layout simulation on a printed circuit board is performed. Conventionally, the method of creating the analog characteristic data includes a method of creating by measuring an actual device, and a method of creating a transistor model corresponding to each buffer by using a circuit simulator configured by software such as SPICE. There has been a method of creating analog characteristic data under various analysis conditions by using and simulating.

[0003]

However, the conventional analog characteristic data creating method has the following problems. According to a method of creating analog characteristic data by a circuit simulator based on a transistor model corresponding to each buffer, it is necessary to create input data for a circuit simulator for each analysis condition, for example. Also, this operation must be performed by a person who has knowledge of the circuit simulator, and cannot be performed by anyone. Therefore, a lot of time is required until analog characteristic data is created. On the other hand, in a method of creating an analog characteristic data by measuring an actual device, a measuring device is naturally required. In addition, it is difficult to estimate analog characteristic data with high accuracy due to measurement errors, manufacturing variations, and the like.To obtain appropriate analog characteristic data, it is necessary to take measures such as increasing the number of measurements. there were.

[0004]

According to the present invention, there is provided a method for creating analog characteristic data, comprising the steps of:
The following measures are taken. That is, command data including device information for specifying a device to be analyzed, analysis conditions for analog characteristics of the device, electrical constants of the device, and information on buffers connected to a plurality of terminals of the device is created in advance. Based on the command data, continuously and repeatedly execute a circuit simulation to obtain voltage-current characteristics including voltage-current characteristics or response speed characteristics for each analysis condition at each terminal of the device, and create analog characteristic data of the entire device I am trying to do it. According to the present invention, since the analog characteristic data creating method is configured as described above, in advance, for example, device information such as a manufacturer name and a product number for specifying a device to be analyzed, and analysis conditions such as a temperature and a power supply voltage. , Electrical constants such as device inductance, capacitance and resistivity,
Command data including information on buffers connected to a plurality of terminals of the device is created. In order to create analog characteristic data, a circuit simulation is performed for each analysis condition. As data necessary for each circuit simulation, data read from command data is used, and the circuit simulation is continuously performed. . From each circuit simulation result, analog characteristic data of the device to be analyzed is obtained. Therefore, the above problem can be solved.

[0005]

FIG. 1 is a functional block diagram showing an outline of a method for creating analog characteristic data according to an embodiment of the present invention. This analog characteristic data creating method is performed mainly on the analog characteristic data creating program 1.
The analog characteristic data creating program 1 reads command data 2 created in advance and creates input data 3 for a circuit simulator. The circuit simulator input data 3 is provided to a circuit simulator 4 composed of software such as spices. The circuit simulator 4
Using the transistor model 5 based on the circuit simulator input data 3, the circuit simulation under the analysis conditions specified by the circuit simulator input data 3 is automatically repeated. The circuit simulation result 6 is passed to the analog characteristic data creation program 1, and the analog characteristic data creation program 1 creates analog characteristic data 7 of the device to be analyzed. Next, a procedure for creating analog characteristic data using the analog characteristic data creating program 1 will be described.

First, command data 2 is created. The command data 1 describes device information for specifying a device to be analyzed, analysis conditions, electrical constants of the device, information of a buffer inside the device connected to a plurality of terminals of the device, and the like. . The device information described in the command data 2 includes information for specifying a device to be analyzed such as a product name and a manufacturer name of the device. The analysis conditions include a temperature, a power supply voltage, and the like in consideration of a use environment of the device, and a maximum value, a minimum value, an average value, and the like are selected and described. The electrical constant of the device is
It corresponds to the definition of a device, and is described by a resistance component (R), a capacitance component (C), and an induction component (L) from a pad of a chip which is a main part of the device to a pin which is a terminal, or The resistance component (R), the capacitance component (C), and the induction component (L) in the plurality of pins are described in correspondence with the pin arrangement. As buffer information, a transistor model corresponding to each pin, a buffer type, and other necessary buffer information are described. As for the type of buffer, whether the buffer is for input,
There is information for output or input / output, and polarity information of the buffer, that is, information on whether or not the inverter is a type of polarity inversion. As other necessary buffer information, for example, in the case of an input buffer, a clamp voltage level corresponding to a logical level “H” and a clamp voltage level corresponding to “L” are described. In the case of an output buffer, the rise time of response speed information and the like are described.

FIG. 2 is a flowchart of the analog characteristic data creation program in FIG. 1. The processing in the analog characteristic data creation program will be described with reference to FIG. In the command data reading process in step S1, the created command data 2 is read. In step S2, for all buffers (all pins)
It is determined whether the process of step S3 described below has been completed. At the first stage, the processing for all buffers has not been completed (NO), so the processing proceeds to step S3. Step S3 is a simulation input data creation process in which the simulation input data 3 is created based on the analysis conditions of the command data 2. That is, in the simulation input data creation processing S3, when the buffer being processed is an input buffer, circuit data for simulating a voltage-current characteristic (hereinafter, referred to as VI characteristic) of the clamp diode is created. In the case of an output buffer, circuit data for simulating the VI characteristics at the time of outputting "H" and "L" and the rise time of the output signal is created. In the case of an input / output buffer, circuit data for simulating all these characteristics is created. The simulation input data creation processing S3 is repeated until it is determined in step S2 that the processing of step S3 has been completed for all buffers (all pins) (YES).

When the creation of the simulation input data 3 for all buffers is completed, the analog characteristic data creation program 1 performs a circuit simulator activation process in step S4. In the circuit simulation activation process in step S4, the analog characteristic data creation program 1 describes the transistor model specified by the command data 2 and the circuit data obtained in the simulation input data creation process S3 in a manner applicable to the circuit simulator 4. These are given to the circuit simulator 4 and activated. Data corresponding to one analysis condition is obtained by the circuit simulator activation process in step S4. Subsequently, it is determined whether or not all the analysis conditions have been completed in the process of step S5, and if all the analysis conditions have not been completed (N
In O), the process returns to step S2, and similar processes (steps SS2 to S4) for other analysis conditions are repeated. As the conditions (temperature, power supply voltage) of the simulation repeatedly performed by the circuit simulator 4, the values described in the command data 2 are used, and three patterns of maximum, minimum, and average are obtained for one characteristic. Be executed.
The analog characteristic creation program 1 obtains a simulation result 6 according to each analysis condition. If it is determined in the process of step S5 that a series of processes corresponding to all the analysis conditions has been completed (YES), the analog characteristic creation program 1 performs an analog characteristic data output process of step S6.

FIG. 3 is a diagram showing an output form of the formatted analog characteristic data 7. In the analog characteristic data output processing in step S6, the device information, the pin arrangement, the electrical constants, and the analysis conditions in the read command data 2 and the respective VI characteristics obtained by repeating the circuit simulator activation processing in step S4 are obtained. And the analog characteristic data 7 is created. The analog characteristic data program 1 formats and outputs analog characteristic data 7 as shown in FIG. 3, for example. FIG. 4 is a flowchart showing a printed circuit board layout simulation using the analog characteristic data 7 in FIG. When a printed circuit board layout simulation is performed, a layout simulation operation model 8 is created based on the analog characteristic data 7 created by the analog characteristic data creation program 1 and stored in the storage medium 9. On the other hand, a transmission line model 11 is extracted from the printed circuit board layout data 10 and stored in the storage medium 12. Each of the storage media 9 and 12 is
The simulation of the printed circuit board is performed using the layout simulation operation model 8 and the transmission line model 11 which are read out from the above.

As described above, in the present embodiment, device information for specifying a device to be analyzed, analysis conditions such as power supply voltage and temperature of the device, electrical constants of the device, and connections to a plurality of terminals of the device are provided. The information of the buffer inside the device is described in the command data 2, and the command data 2 is applied to the circuit simulator 4 to automatically obtain the VI characteristics for each analysis condition. Therefore, in the related art, for example, data for inputting a circuit simulator is created for each analysis condition, but the time required for the creation can be omitted, and the creation of data becomes easy. Therefore, it is possible to reduce the number of manufacturing steps when performing the layout simulation of the printed circuit board. Note that the present invention is not limited to the above embodiment, and various modifications are possible. For example, in the above embodiment, spice (SPICE) having high versatility is described as an example. However, software constituting the circuit simulator 4 may be other software using analog characteristic data. Also,
The data created by the analog characteristic data creation program 1 does not necessarily have to be used for the layout simulation of the printed circuit board in FIG.
It is also applicable when evaluating the transmission characteristics between a printed circuit board, a cable, a print, and an IC.

[0011]

As described in detail above, according to the present invention, device information for specifying a device, analysis conditions for analog characteristics, electrical constants of the device, and the internal of the device connected to a plurality of terminals. Command data including the information of the buffer in advance, and based on the command data, continuously perform a circuit simulation for obtaining a voltage-current characteristic including a voltage-current characteristic or a response speed characteristic for each analysis condition at each terminal of the device. And repeatedly executed to create analog characteristic data of the entire device. Conventionally, for example, data for inputting a circuit simulator was created for each analysis condition. Can be easily created.

[Brief description of the drawings]

FIG. 1 is a functional block diagram illustrating an outline of a method for creating analog characteristic data according to an embodiment of the present invention.

FIG. 2 is a flowchart of an analog characteristic data creation program in FIG.

FIG. 3 is a diagram showing an output form of formatted analog characteristic data 7;

FIG. 4 is a flowchart showing a printed circuit board layout simulation using analog characteristic data 7 in FIG. 1;

[Explanation of symbols]

 1 Analog characteristic data creation program 2 Command data 3 Circuit simulation input data 4 Circuit simulator 5 Transistor model 6 Simulation result 7 Analog characteristic data

Claims (1)

[Claims] 1. Device information for specifying a device to be analyzed, analysis conditions for analog characteristics in the device,
Command data including an electrical constant of the device and information of a buffer inside the device connected to a plurality of terminals of the device is created, and the analysis condition at each terminal of the device is based on the command data. An analog characteristic data generating method for generating analog characteristic data of the entire device by continuously and repeatedly executing a circuit simulation for obtaining a voltage-current characteristic including a voltage-current characteristic or a response speed characteristic for each device.