IP Library Granted Patent US 7,412,678
Granted Patent B2
US 7,412,678 · App. 10/859,874 · Granted Aug 12, 2008

Method and computer program for management of synchronous and asynchronous clock domain crossing in integrated circuit design

Assignee: LSI Corporation
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Quick Facts
Patent No.
US 7,412,678
App. No.
10/859,874
Granted
Aug 12, 2008
Kind
B2
Abstract

A method and computer program are disclosed for managing synchronous and asynchronous clock domain crossings that include steps of: (a) receiving as input an integrated circuit design; (b) identifying paths between synchronous clock domains and paths between asynchronous clock domains in the integrated circuit design; and (c) if a path between synchronous clock domains is defined as a false path in the integrated circuit design, then reporting a fatal violation.

Claims (24)

1. A method comprising steps of:

receiving as input an integrated circuit design;

receiving as input a set of false path timing constraints to define false paths in the integrated circuit design;

identifying paths in the integrated circuit design that exist between one synchronous clock domain and another synchronous clock domain and paths in the integrated circuit design that exist between one asynchronous clock domain and another asynchronous clock domain; and

reporting a fatal violation when a path between synchronous clock domains is defined as a false path in the integrated circuit design.

2. The method of claim 1 further comprising a step of reporting a warning when no path exists between synchronous clock domains.

3. The method of claim 2 further comprising a step of reporting a path that exists between asynchronous clock domains as a false path.

4. The method of claim 2 further comprising a step of reporting a path that exists between asynchronous clock domains and is not reported as a false path and is not synchronized as a fatal violation.

5. The method of claim 4 further comprising a step of synchronizing the path between asynchronous clock domains that is not reported as a false path and is not synchronized.

6. The method of claim 4 further comprising a step of defining the path between asynchronous clock domains that is not reported as a false path and is not synchronized as a false path.

7. The method of claim 1 , the integrated circuit design comprising a netlist.

8. The method of claim 1 , the integrated circuit design comprising register transfer level code.

9. A computer readable storage medium tangibly embodying program instructions that when executed by a computer implement a method of managing synchronous and asynchronous clock domain crossings, the method comprising steps of:

receiving as input an integrated circuit design;

receiving as input a set of false path timing constraints to define false paths in the integrated circuit design;

identifying paths in the integrated circuit design that exist between one synchronous clock domain and another synchronous clock domain and paths in the integrated circuit design that exist between one asynchronous clock domain and another asynchronous clock domain; and

reporting a fatal violation when a path between synchronous clock domains is defined as a false path in the integrated circuit design.

10. The computer readable storage medium of claim 9 further comprising a step of reporting a warning when no path exists between synchronous clock domains.

11. The computer readable storage medium of claim 10 further comprising a step of reporting a path that exists between asynchronous clock domains as a false path.

12. The computer readable storage medium of claim 10 further comprising a step of reporting a path that exists between asynchronous clock domains and is not reported as a false path and is not synchronized as a fatal violation.

13. The computer readable storage medium of claim 12 further comprising a step of synchronizing the path between asynchronous clock domains that is not reported as a false path and is not synchronized.

14. The computer readable storage medium of claim 12 further comprising a step of defining the path between asynchronous clock domains that is not reported as a false path and is not synchronized as a false path.

15. The computer readable storage medium of claim 9 , the integrated circuit design comprising a netlist.

16. The computer readable storage medium of claim 9 , the integrated circuit design comprising register transfer level code.

Assignments (9)
RELEASE OF SECURITY INTEREST Recorded Apr 15, 2022
From: CORTLAND CAPITAL MARKET SERVICES LLC
To: HILCO PATENT ACQUISITION 56, LLC; BELL SEMICONDUCTOR, LLC; BELL NORTHERN RESEARCH, LLC
Reel/Frame 059720/0223 →
SECURITY INTEREST Recorded Feb 1, 2018
From: HILCO PATENT ACQUISITION 56, LLC; BELL SEMICONDUCTOR, LLC; BELL NORTHERN RESEARCH, LLC
To: CORTLAND CAPITAL MARKET SERVICES LLC, AS COLLATERAL AGENT
Reel/Frame 045216/0020 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Dec 17, 2017
From: AVAGO TECHNOLOGIES GENERAL IP (SINGAPORE) PTE. LTD.; BROADCOM CORPORATION
To: BELL SEMICONDUCTOR, LLC
Reel/Frame 044887/0109 →
TERMINATION AND RELEASE OF SECURITY INTEREST IN PATENT RIGHTS (RELEASES RF 032856-0031) Recorded Feb 2, 2016
From: DEUTSCHE BANK AG NEW YORK BRANCH, AS COLLATERAL AGENT
To: LSI CORPORATION; AGERE SYSTEMS LLC
Reel/Frame 037684/0039 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Apr 3, 2015
From: LSI CORPORATION
To: AVAGO TECHNOLOGIES GENERAL IP (SINGAPORE) PTE. LTD.
Reel/Frame 035390/0388 →
CHANGE OF NAME Recorded Jun 6, 2014
From: LSI LOGIC CORPORATION
To: LSI CORPORATION
Reel/Frame 033102/0270 →
PATENT SECURITY AGREEMENT Recorded May 8, 2014
From: LSI CORPORATION; AGERE SYSTEMS LLC
To: DEUTSCHE BANK AG NEW YORK BRANCH, AS COLLATERAL AGENT
Reel/Frame 032856/0031 →
MERGER Recorded Feb 19, 2008
From: LSI SUBSIDIARY CORP.
To: LSI CORPORATION
Reel/Frame 020548/0977 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Jun 2, 2004
From: LAHNER, JUERGEN; ADUSUMALLI, SRINIVAS; BYRN, JONATHAN
To: LSI LOGIC CORPORATION
Reel/Frame 015432/0876 →
Continuity (1)
Related Publication 20050273741A1 · Dec 8, 2005