JPH05165912A - Consumed energy calculator for semiconductor integrated circuit - Google Patents

Abstract

PURPOSE:To obtain a high-accuracy calculated result with a processing in a short time by calculating energy consumption for the unit of each circuit from a library for consumed energy calculation corresponding to a logical arithmetic signal. CONSTITUTION:This device is equipped with a circuit information file 5 to store the information of a network, logical simulation means to output the logical arithmetic signal at an input/output terminal for the unit of the circuit by executing the logical arithmetic of a semiconductor integrated circuit while extracting required information from this circuit information file 5, and library 8 for consumed energy calculation to store energy consumed for the unit of each circuit as the function of the logical arithmetic signal at the input/output terminal for the unit of the circuit. Then, the consumed energy in the semiconductor integrated circuit is calculated from the information obtained from the library 8 for consumed energy calculation corresponding to the logical arithmetic signal outputted by the logical simulation means and the information of the wiring load capacity of the network calculated from the circuit information file 5.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power consumption calculation device for a semiconductor integrated circuit, and more particularly to a device for efficiently calculating the power consumption of a semiconductor integrated circuit using an output result of a logic simulation.

[0002]

2. Description of the Related Art FIG. 4 is a block diagram showing a conventional power consumption calculation device for a semiconductor integrated circuit. In the figure, 1 is a keyboard, 2 is an input / output interface, 3 is a CRT,
Reference numeral 4 is a CPU, and 5 is a circuit information file, which stores information about elements, functional blocks, and nets connecting these input / output terminals, which form the semiconductor integrated circuit. 6 is R
AM and 7 are ROMs, in which software programs which are means for calculating power consumption are stored.

Next, the processing flow will be described with reference to FIG. First, the connection information is extracted from the circuit information file and temporarily stored in the connection information file. Similarly, the wiring load capacitance of each net is extracted from the circuit information file and is temporarily stored in the wiring load capacitance file. Next, circuit simulation is performed based on the information in each file. from now on,
The power consumption of the semiconductor integrated circuit is obtained by calculating the signal value of each net and the current value, calculating the power consumption generated in each element, the functional block and the net, and integrating them over the entire semiconductor integrated circuit.

[0004]

Since the conventional power consumption calculation apparatus for a semiconductor integrated circuit is configured as described above, the signal of each net is determined by the circuit simulation.
Not only the magnitude but also the signal delay and signal bluntness are calculated in detail, and the power consumption of each part is calculated based on these detailed signal outputs, so high calculation accuracy can be obtained, but the processing time becomes longer. There was a problem. On the other hand, there is also a method of calculating the power consumption by simplifying the signal blunting by a first-order approximation or the like and using a transistor level logic simulation, but it has not been an effective solution to the above problems. The present invention has been made in order to solve the above problems, and an object thereof is to obtain a power consumption calculation device for a semiconductor integrated circuit capable of significantly shortening the processing time without substantially lowering the calculation accuracy. And

[0005]

A power consumption calculation apparatus for a semiconductor integrated circuit according to the present invention comprises a plurality of circuit units which are made up of elements or functional blocks and constitute a semiconductor integrated circuit to be calculated, and input / output of these circuit units. A circuit information file that stores information on nets that connect terminals, and necessary information is extracted from this circuit information file to perform a logical operation of the semiconductor integrated circuit and output logical operation signals at the input / output terminals of each circuit unit. And a power consumption calculation library for storing the power consumed in each circuit unit as a function of the logic operation signal at the input / output terminal of the circuit unit, and the logic operation signal output from the logic simulation unit. Corresponding to the information obtained from the power consumption calculation library and the circuit information file Obtained from the information of the wiring load capacity of the net is obtained so as to calculate the power consumption in the semiconductor integrated circuit.

[0006]

In the present invention, the logic simulation is executed based on the information from the circuit information file. Based on the logical operation signal at the input / output terminal of each circuit unit obtained by this, the power consumption generated in the circuit unit is read from the power consumption calculation library, and these are integrated to calculate the power consumption of all the circuit units. ..

[0007]

FIG. 1 is a block diagram showing a power consumption calculation apparatus for a semiconductor integrated circuit according to an embodiment of the present invention, which is different from the conventional one in that a power consumption calculation library 8 is added and a ROM 7 is provided. It is the content of the stored processing flow. Hereinafter, these will be mainly described in detail.

First, the power consumption calculation library 8 will be described. A semiconductor integrated circuit is composed of a combination of many elements or functional blocks, and each of these elements or functional blocks is a circuit unit. Then, the amount of mobile charges actually generated in the circuit unit is obtained in advance according to the signal of the input / output terminal derived from the circuit unit, and this is stored in the power consumption calculation library 8.

That is, FIG. 2 concretely shows a part of the file contents of the power consumption calculation library 8. In the figure, A1 is an element name or a functional block name which is a circuit unit, and B1 is a circuit unit. One input / output terminal name derived from A1 and B2 are other input / output terminal names derived from the circuit unit A1. C1 and C2 are input / output terminals B1
As will be described later, this signal is a signal obtained in the form of a so-called logic simulation output, which is defined as a logical operation signal here. Therefore, the logical operation signal does not take into consideration, for example, signal blunting mentioned in the prior art.

D1 and D2 are the amounts of mobile charge generated in the circuit unit A1 when the signals at the terminal B1 are C1 and C2, respectively. Since it can be considered that the voltage is constant in the logic simulation, this mobile charge amount is a value that is directly proportional to the power consumption. Then, for this mobile charge amount stored in the power consumption calculation library 8, the value of the mobile charge amount actually generated in the circuit unit A1 when the logical operation signal becomes C1 or C2 is separately calculated by circuit simulation or the like. Is used by being obtained in advance. Since the same applies to C3, D3 ..., Description thereof will be omitted.

Next, the processing flow will be described with reference to FIG.
Similar to the conventional method, the connection information and the net wiring load capacity are extracted from the circuit information file, and the logic simulation is executed based on these pieces of information. Then, when the logical operation signal at the input / output terminal of each circuit unit is obtained, the power consumption calculation library 8 is accessed to read the mobile charge amount of the circuit unit corresponding to each signal and convert these to the power consumption amount. The total is integrated for the entire semiconductor integrated circuit.
The power consumption of the semiconductor integrated circuit is obtained by summing the power consumption obtained from the information of the wiring load capacitance and the power consumption obtained from the information of the power consumption calculation library 8 described above.

According to the present invention, since the logic simulation is used instead of the circuit simulation for calculating the signal waveform dullness in detail, high-speed processing is possible.
Moreover, it is possible to obtain a sufficiently accurate result regarding the power consumption.

[0013]

As described above, according to the present invention, the logic simulation is executed to obtain the logic operation signal, and the power consumption of each circuit unit is calculated from the power consumption calculation library corresponding to this signal. Highly accurate calculation results can be obtained in a short time.

[Brief description of drawings]

FIG. 1 is a block diagram showing a power consumption calculation device for a semiconductor integrated circuit according to an embodiment of the present invention.

FIG. 2 is a diagram showing a part of file contents of a power consumption calculation library in FIG.

FIG. 3 is a diagram showing a processing flow in the case of an embodiment of the present invention.

FIG. 4 is a block diagram showing a conventional power consumption calculation device for a semiconductor integrated circuit.

FIG. 5 is a diagram showing a processing flow in a conventional case.

[Explanation of symbols]

 5 Circuit information file 8 Power consumption calculation library

Claims (1)

[Claims] 1. A circuit information file for storing information of a plurality of circuit units which constitute a semiconductor integrated circuit to be calculated and which comprises elements or functional blocks, and a net which connects input / output terminals of these circuit units, and this circuit information. Logic simulation means for extracting necessary information from a file to perform a logical operation of the semiconductor integrated circuit and outputting a logical operation signal at an input / output terminal of each circuit unit, and power consumed by each circuit unit And a circuit information file which is obtained from the power consumption calculation library corresponding to the logic operation signal output from the logic simulation means. From the information on the wiring load capacitance of the net obtained from A power consumption calculation device for a semiconductor integrated circuit for calculating power consumption.