IBIS correction tool, IBIS correction method, and waveform simulation device

Abstract

An IBIS correction tool which can be used assembled in a waveform simulation device and corrects IBIS data for a certain specific power supply voltage V0 to IBIS data for a desired power supply voltage V1 with a higher precision than the past, that is, an IBIS correction tool configured so as to read IBIS data for a power supply voltage V0 as numerical data of x-y coordinates at a data input unit, find a relative ratio (correction coefficient) between this numerical data and numerical data for a power supply voltage V1 on its x-y coordinates at a correction coefficient calculating unit, and obtain corrected IBIS data corrected for the power supply voltage V1 according to that correction coefficient at a corrected IBIS data generating unit.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

There and other objects and features of the present invention will be more apparent from the following description of the preferred embodiments given with reference to the accompanying drawings, wherein:

FIG. 1 is a diagram showing a basic configuration of an IBIS correction tool according to the present invention,

FIG. 2 is a flow chart of an IBIS correction method according to the present invention,

FIG. 3 is a diagram showing a waveform simulation device provided with the IBIS correction tool according to the present invention,

FIG. 4 is a diagram for explaining arithmetic operations for IBIS data correction based on the present invention,

FIG. 5 is a flow chart of detailed computation operation of the correction tool based on the present invention,

FIG. 6 is a diagram showing an output voltage-current characteristic curve C′ corrected by an IBIS correction tool according to the present invention,

FIG. 7 is a diagram showing the characteristic curves C′ representing the corrected IBIS data in the present invention and the conventional device in comparison,

FIG. 8 is a functional block diagram of a waveform simulation device according to the present invention,

FIG. 9 is a diagram showing an example of a semiconductor device covered by the present invention,

FIG. 10 is a diagram showing an output voltage-current characteristic focused on in the present invention, and

FIG. 11 is a diagram for explaining the correction of an output electrical characteristic curve according to a prior art method.

Claims

1. An IBIS correction apparatus for converting IBIS data provided for a specific power supply voltage for a specific semiconductor device to corrected IBIS data corrected so as to match with a desired power supply voltage different from said specific power supply voltage for said specific semiconductor device, comprising: a data input unit for reading all data for an electrical characteristic of an output of said specific semiconductor device defined by said IBIS data as numerical data consisting of x-y coordinates;a correction coefficient calculating unit for calculating a relative ratio of said numerical data of the x-y coordinates read at said data input unit for said specific power supply voltage and numerical data represented on the same x-y coordinates for said desired power supply voltage as a correction coefficient; anda corrected IBIS data generating unit for converting IBIS data corresponding to said specific power supply voltage on said x-y coordinates to said corrected IBIS data corrected so as to match with said desired power supply voltage.

2. An IBIS correction apparatus as set forth in claim 1, wherein said correction coefficient calculating unit represents said numerical data consisting of the x-y coordinates read at said data input unit as a reference vector using an origin of the x-y coordinates as the base point and uses the relative ratio between a magnitude of the desired vector corresponding to said desired power supply voltage on the same x-y coordinates and the magnitude of the reference vector as the correction coefficient, andwherein said corrected IBIS data generating unit converts the IBIS data corresponding to said specific power supply voltage to said corrected IBIS data corresponding to said desired power supply voltage based on said correction coefficient and an angle of said reference vector relative to said origin.

3. An IBIS correction apparatus as set forth in claim 2, wherein: said data input unit reads said specific power supply voltage as Vddn, an output voltage thereof as Vn, and an output current thereof as In for said electrical characteristic of the output, said correction coefficient calculating unit calculates a magnitude dn of said reference vector as dn=√(Vn2+In2), calculates an angle On of said reference vector relative to said origin as θn=tan−1(In/Vn), and, when said desired power supply voltage is Vddm, finds said relative ratio as Vddm/Vddn, andsaid corrected IBIS data generating unit first calculates the magnitude dm of said desired vector as dm=(Vddm/Vddn)×dn and generates an output voltage Vm and an output current Im as the corrected IBIS data corresponding to said desired power supply voltage as Vm=dm×cos θn and Im=dm×sin θn.

4. An IBIS correction apparatus as set forth in claim 1, further comprising: a correction requirement judging unit provided between said data input unit and said correction coefficient calculating unit,the correction requirement judging unit judging that the correction is necessary and activating said correction coefficient calculating unit and said corrected IBIS data generating unit only when said desired power supply voltage does not coincide with said specific power supply voltage when obtaining said electrical characteristic of the output read at said data input unit.

5. An IBIS correction apparatus as set forth in claim 1, further comprising a corrected IBIS library for storing the corrected IBIS data generated by said corrected IBIS data generating unit so that it can be freely read out and providing it for utilization at the outside.

6. An IBIS correction method for converting IBIS data provided for a certain specific power supply voltage for a certain semiconductor device to corrected IBIS data corrected so as to match with a desired power supply voltage different from that specific power supply voltage for that semiconductor device, comprising: a first step of reading all data for an electrical characteristic of the output of said semiconductor device defined by said IBIS data as numerical data consisting of x-y coordinates;a second step of calculating a relative ratio between said numerical data consisting of the x-y coordinates read at said first step for said specific power supply voltage and numerical data represented on the same x-y coordinates for said desired power supply voltage as a correction coefficient; anda third step of converting the IBIS data corresponding to said specific power supply voltage to corrected IBIS data corrected so as to match with said desired power supply voltage according to said correction coefficient calculated at said second step.

7. A waveform simulation device comprising: a modeling unit receiving as input IBIS data and interconnect data provided from the outside and preparing a device model and an interconnect model;a waveform simulating unit receiving as input information of said device model and interconnect model prepared at said modeling unit and simulating an output waveform of a semiconductor device; anda waveform display unit for providing a simulated output waveform to a user, whichforms a model generating unit including said modeling unit, introduces an IBIS correction tool to an input side of said IBIS data in the model generating unit, and has the IBIS correction tool convert IBIS data provided for a specific power supply voltage for a certain semiconductor device to corrected IBIS data corrected so as to match with a desired power supply voltage different from said specific power supply voltage for said specific semiconductor device.

8. A computer readable medium having a program stored therein to cause a computer to execute operations for converting IBIS data provoded for a specific power supply voltage for a specific semiconductor device to corrected IBIS data corrected sa as to match with a desired power supply voltage different from said specific power supply voltage for said specific semiconductor device, said operations comprising: reading all data for an electrical characteristic of the output of said semiconductor device defined by said IBIS data as numerical data consisting of x-y coordinates;calculating a relative ratio between said numerical data consisting of x-y coordinates read at said reading operation for said specific power supply voltage and numerical data represented on the same x-y coordinates for said desired power supply voltage as a correction coefficient; andconverting the IBIS data corresponding to said specific power supply voltage to corrected IBIS data corrected so as to match with said desired power supply voltage according to said correction coefficient calculated at said calculating operation.