Method and apparatus for efficient computation of moments in interconnect circuits

A data processing system implemented method for efficiently computing moments in interconnect circuit, the method comprising:

• defining a circuit representation, wherein the circuit representation comprises a first port, a second port and a plurality of circuit elements including at least one resistor and one capacitor, disposed between the first port and the second port;
• converting each capacitor in the circuit representation into an equivalent current source;
• connecting a first voltage source to the first port and a second voltage source to the second port;
• defining a Thevenin equivalent circuit, wherein the first voltage source is a first Thevenin voltage source and a connected resistor is a first Thevenin resistor;
• converting the Thevenin equivalent circuit, including the first Thevenin voltage source and the first Thevenin resistor, to a first Norton equivalent circuit wherein the first Norton equivalent circuit includes a first Norton resistor and a first Norton current source;
• combining the first Norton current source and a connected first current source forming a second equivalent current source, wherein the second equivalent current source is a second Norton current source;
• converting the first Norton equivalent circuit including the second Norton current source and the first Norton resistor, into a second Thevenin equivalent circuit, wherein the second Thevenin equivalent circuit includes a second Thevenin resistor and a second Thevenin current source;
• determine if the second Thevenin equivalent circuit can be converted into a second Norton equivalent circuit;
• on the basis of the determination of the second Thevenin equivalent circuit being convertible into a second Norton equivalent circuit perform the steps of:
• converting the second Thevenin equivalent circuit, including the second Thevenin voltage source and the second Thevenin resistor, to a second Norton equivalent circuit wherein the second Norton equivalent circuit includes a second Norton resistor and a third Norton current source;
• combining the third Norton current source and a connected second current source forming a third equivalent current source, wherein the third equivalent current source is a fourth Norton current source;
• converting the second Norton equivalent circuit, including the fourth Norton current source and the second Norton resistor, into a third Thevenin equivalent circuit wherein the third Thevenin equivalent circuit include a third Thevenin resistor and a third Thevenin current source;
• wherein a process is performed whereby the steps of convert a Thevenin equivalent circuit into a Norton equivalent circuit which is then converted to another Thevenin equivalent are repeated until a final Thevenin equivalent circuit is obtained which is not convertible into another Norton equivalent circuit;
• wherein Thevenin Norton Thevenin conversions are reformed until a determination is made that a current can he determined at the second voltage source at the second port;
• on the basis of the determination of the second Thevenin equivalent circuit not being convertible into a second Norton equivalent circuit, calculating is a second current across the second voltage source across the second port;
• determining a moment of the circuit representation using currents calculated across at least one of the first and second voltage sources;
• merging all capacitors and resistors connected in series or connected in parallel;
• marking all nonlinear nodes as ports;
• marking all inductance terminal nodes and grounded resistance nodes as ports;
• marking all nodes with three or more incident resistors as ports;
• and
• collecting all circuit elements between two ports in a depth-first manner.

A data processing system for efficiently computing moments in interconnect circuit comprising:

• defining means for defining a circuit representation, wherein the circuit representation comprises a first port, a second port and a plurality of circuit elements including at least one resistor and one capacitor, disposed between the first port and the second port;
• converting means for converting each capacitor in the circuit representation into an equivalent current source;
• connecting means for connecting a first voltage source to the first port and a second voltage source to the second port;
• defining means for defining a Thevenin equivalent circuit, wherein the first voltage source is a first Thevenin voltage source and a connected resistor is a first Thevenin resistor;
• converting means for converting the Thevenin equivalent circuit, including the first Thevenin voltage source and the first Thevenin resistor, to a first Norton equivalent circuit wherein the first Norton equivalent circuit includes a first Norton resistor and a first Norton current source;
• combining means for combining the first Norton current source and a connected first current source forming a second equivalent current source, wherein the second equivalent current source is a second Norton current source;
• converting means for converting the first Norton equivalent circuit, including the second Norton current source and the first Norton resistor, into a second Thevenin equivalent circuit, wherein the second Thevenin equivalent circuit includes a second Thevenin resistor and a second Thevenin current source;
• determining means for determining if the second Thevenin equivalent circuit can be converted into a second Norton equivalent circuit;
• performing means for performing the steps of:
• converting the second Thevenin equivalent circuit, including the second Thevenin voltage source and the second Thevenin resistor, to a second Norton equivalent circuit wherein the second Norton equivalent circuit includes a second Norton resistor and a third Norton current source;
• combining the third Norton current source and a connected second current source forming a third equivalent current source, wherein the third equivalent current source is a fourth Norton current source;
• converting the second Norton equivalent circuit, including the fourth Norton current source and the second Norton resistor, into a third Thevenin equivalent circuit, wherein the third Thevenin equivalent circuit includes a third Thevenin resistor and a third Thevenin current source;
• wherein a process is performed whereby the steps of converting a Thevenin equivalent circuit into a Norton equivalent circuit which is then converted to another Thevenin equivalent are repeated until a final Thevenin equivalent circuit is obtained which is not convertible into another Norton equivalent circuit;
• wherein Thevenin-Norton-Thevenin conversions are performed until a determination is made that a current can be determined at the second voltage source at the second port;
• calculating means for calculating a second current across the second voltage source across the second port on the basis of the determination of the second Thevenin equivalent circuit not being convertible into a second Norton equivalent circuit;
• and
• determining means for determining a moment of the circuit representation using currents calculated across at least one of the first and second voltage sources.

A data processing system for efficiently computing moments in interconnect circuit comprising:

• receiving means for receiving a representative circuit;
• partitioning means for partitioning the representative circuit into at least one representative two-port circuit;
• connecting means for connecting a representative voltage source at each port of the representative two-port circuit;
• converting means for converting each representative capacitor into a representative voltage source;
• converting means for converting each representative inductor into a representative current source;
• combining means for combining connected like-type representative circuit elements;
• performing means for recursively performing Thevenin to Norton to Thevenin conversions on the representative circuit elements, such that a Thevenin equivalent circuit is converted to Norton equivalent circuit which is then converted to another Thevenin equivalent circuit, the performing means including performing Thevenin-Norton-Thevenin conversions beginning at one port such that a Thevenin equivalent circuit is converted to Norton equivalent circuit which is then converted to another Thevenin equivalent circuit, wherein the Thevenin-Norton-Thevenin recursive process is performed until a determination is made that a current can be determined at a voltage source at the other at the other port;
• whereby Thevenin to Norton to Thevenin conversions arm repeated until a final Thevenin equivalent circuit is obtained which is not convertible into another Norton equivalent circuit;
• determining means for determining a current across a representative voltage source at a port;
• and determining means for determining a moment for the representative circuit using a current across a representative voltage source at a port.

A data processing system for efficiently computing moments in interconnect circuit comprising:

• performing means for recursively performing Thevenin to Norton to Thevenin conversions on a representative circuit having at least two ports, the performing means including performing Thevenin-Norton-Thevenin conversions beginning at one of the at least two ports such that a Thevenin equivalent circuit is converted to Norton equivalent circuit which is then, converted to another Thevenin equivalent circuit, wherein the Thevenin-Norton-Thevenin recursive process is performed until a determination is made that a current can be determined at a voltage source at the other at least two ports;
• determining means for determining a current across a representative voltage source located at a port;
• determining means for determining a moment for the representative circuit using a current across a representative voltage source at a port;
• and
• performing means for performing one of circuit element values computation, circuit timing computation and circuit simulation based on the moment.

A computer program product for efficiently computing moments in interconnect circuit, performed on a data processing system, implemented on a computer readable memory and comprising a series of instructions, the instructions comprising:

• performing instructions for recursively performing Thevenin to Norton to Thevenin conversions on a representative circuit having at least two ports, the performing instructions including performing Thevenin-Norton-Thevenin conversions beginning at one of the at least two ports such that a Thevenin equivalent circuit is converted to Norton equivalent circuit which is then converted to another Thevenin equivalent circuit, wherein the Thevenin-Norton-Thevenin recursive process is performed until a determination is made that a current is be determined at a voltage source at the other at least two ports;
• whereby Thevenin to Norton to Thevenin conversions are repeated until a final Thevenin equivalent circuit is obtained which is not convertible into another Norton equivalent circuit;
• determining means for determining a moment for the representative circuit using a current across a representative voltage source at a port;
• and
• performing means for performing one of circuit element values computation, circuit timing computation and circuit simulation based on the moment.