Pseudo-inverter configuration for signal electromigration analysis

Patent metadata

Field	Value
Publication number	US-10192012-B1
Application number	US-201715470722-A
Country	US
Kind code	B1
Filing date	Mar 27, 2017
Priority date	Mar 27, 2017
Publication date	Jan 29, 2019
Grant date	Jan 29, 2019

Abstract

A method for determining a signal electromigration effect in a circuit includes obtaining a partition netlist from a partition of an integrated circuit netlist and identifying a complementary netlist that couples a second input with the output is provided. The complementary netlist is logically independent from the reference netlist. The method includes modifying the partition netlist to couple the reference netlist and the complementary netlist in an inverting configuration, and providing an electromagnetic pulse to at least one of the first input or the second input to induce a current through one of the plurality of circuit components. The method also includes determining an electromigration effect from the current on the one of the plurality of circuit components.

First claim

The invention claimed is:

1. A computer-implemented method for determining a signal electromigration effect in a circuit, comprising:
obtaining, with a circuit design tool, a partition netlist from a partition of an integrated circuit netlist, the partition netlist comprising an identification of a plurality of circuit components;
identifying, with a characterization tool, a reference netlist that couples a first input of the partition netlist with an output of the partition netlist;
identifying, with the characterization tool, a complementary netlist that couples a second input of the partition netlist with the output of the partition netlist, wherein the complementary netlist is logically independent from the reference netlist;
modifying the partition netlist to couple the reference netlist and the complementary netlist in an inverting configuration wherein the output of the partition netlist is a same output when the first input is a logical inverse of the second input;
providing an electromagnetic pulse to at least one of the first input or the second input of the partition netlist to induce a current through one of the plurality of circuit components; and
determining an electromigration effect from the current on the one of the plurality of circuit components.

2. The computer-implemented method of claim 1 , wherein identifying a complementary netlist comprises selecting a plurality of circuit components in the partition netlist that are decoupled from the reference netlist.

3. The computer-implemented method of claim 1 , wherein modifying the partition netlist to couple the reference netlist and the complementary netlist in an inverting configuration comprises selecting the second input of the partition netlist to invert a logic state induced at the output of the partition netlist by the first input of the partition netlist.

4. The computer-implemented method of claim 1 , wherein modifying the partition netlist comprises coupling a first terminal in a first one of the plurality of circuit components with the reference netlist and coupling a second terminal in a second one of the plurality of circuit components with the complementary netlist so that a transition from a low-to-high state occurs in the output of the partition netlist occurs when a transition from a low-to-high state occurs in the first input of the partition netlist or when a transition from a high-to-low state occurs in the second input of the partition netlist.

5. The computer-implemented method of claim 1 , wherein modifying the partition netlist comprises coupling a transistor gate with the reference netlist when the transistor gate controls a positively doped channel substrate associated with a first power source in the partition netlist, and with the complementary netlist when the transistor gate controls a negatively doped channel substrate associated with a second power source in the partition netlist.

6. The computer-implemented method of claim 1 , wherein modifying the partition netlist comprises coupling a transistor gate with the reference netlist when the transistor gate controls a negatively doped channel substrate associated with a first ground source in the partition netlist, and with the complementary netlist when the transistor gate controls a positively doped channel substrate associated with a second ground source in the partition netlist.

7. The computer-implemented method of claim 1 , wherein modifying the partition netlist comprises coupling a transistor gate with a power source when the transistor gate controls a negatively doped channel substrate, and with a ground source when the transistor gate controls a positively doped channel substrate.

8. The computer-implemented method of claim 1 , wherein modifying the partition netlist comprises coupling a power source to some constrained inputs and coupling a ground to other constrained inputs to satisfy a constraint in a constrained input setting for a computational thread in a cloud computing environment.

9. The computer-implemented method of claim 1 , wherein:
providing an electromagnetic pulse to at least one of the first input or the second input of the partition netlist comprises providing an input stimulus vector having a first electromagnetic pulse for the first input and a second electromagnetic pulse to the second input of the partition netlist, and
the second electromagnetic pulse is inverted relative to the first electromagnetic pulse.

10. A system, comprising:
a memory, storing instructions; and
at least one processor that executes the instructions to:
obtain, with a circuit design tool, a partition netlist from a partition of an integrated circuit netlist, the partition netlist comprising an identification of a plurality of circuit components;
identify, with a characterization tool, a reference netlist that couples a first input of the partition netlist with an output of the partition netlist;
identify, with a characterization tool, a complementary netlist that couples a second input of the partition netlist with the output, wherein the complementary netlist is logically independent from the reference netlist;
modify the partition netlist to couple the reference netlist and the complementary netlist in an inverting configuration wherein the output of the partition netlist is a same output when the first input is a logical inverse of the second input;
provide an electromagnetic pulse to at least one of the first input or the second input of the partition netlist to induce a current through one of the plurality of circuit components; and
determine an electromigration effect from the current on the one of the plurality of circuit components.

11. The system of claim 10 , wherein the at least one processor comprises a master processor and a slave processor coupled through a network connection, wherein the master processor is configured to provide the slave processor with an initialization routine to execute at least one portion of the instructions, and to control an execution of the at least one portion of the instructions by the slave processor.

12. The system of claim 10 , wherein the at least one processor comprises a first processor partially executing at least one portion of the instructions in a first computational thread and a second processor partially performing at least a second portion of the instructions in a second computational thread.

13. The system of claim 10 , wherein the at least one processor comprises a first processor configured to identify the reference netlist in a first computational thread, and a second processor configured to identify the complementary netlist in a second computational thread.

14. The system of claim 10 , wherein the at least one processor comprises a master processor and a slave processor coupled through a network connection, wherein the master processor is configured to provide the partition netlist from a partition of an integrated circuit netlist to the slave processor, and the slave processor executes the instructions.

15. The system of claim 10 , wherein to modify the partition netlist the at least one processor executes instructions to couple a transistor gate that is associated to a power source in the partition netlist with the reference netlist when the transistor gate controls a positively doped channel substrate and with the complementary netlist when the transistor gate controls a negatively doped channel substrate.

16. The system of claim 10 , wherein to modify the partition netlist the at least one processor executes instructions to couple a transistor gate that is associated to a ground

Assignees

• Cadence Design Systems Inc

Inventors

• Wehbeh Jalal
• Ramakrishnan Aswin
• Keller Igor
• Politi Federico
• Thomas Ajish

Classifications

• G06F30/367 Primary

  Design verification, e.g. using simulation, simulation program with integrated circuit emphasis [SPICE], direct methods or relaxation methods · CPC title

• G06F2119/04

  Ageing analysis or optimisation against ageing · CPC title

• G06F17/5045

  Physics · mapped topic

• G06F17/5036

  Physics · mapped topic

• G06F17/5022 Primary

  Physics · mapped topic