Method and apparatus for automatically adjusting noise immunity of an integrated circuit

• US 6,201,431 B1
• Filed: 04/29/1999
• Issued: 03/13/2001
• Est. Priority Date: 04/29/1999
• Status: Expired due to Fees

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Allen, David Howard, Stasiak, Daniel Lawrence
• Primary Examiner(s): Wells, Kenneth B.
• Assistant Examiner(s): COX, CASSANDRA F
• Application Number:
  US09/302,012
• Time in Patent Office: 684 Days
• Field of Search: 327/115, 327/20, 327/292, 327/298, 327/387, 327/388, 327/541, 327/519, 327/551, 327/552, 327/553, 327/379, 327/25, 326/22, 326/31, 326/93, 326/94, 326/95, 326/96
• US Class Current: 327/379
• CPC Class Codes: H03K 19/00346 Modifications for eliminating interference or parasitic voltages or currents
• CPC Class Codes: H04L 7/0008 Synchronisation information channels, e.g. clock distribution lines

Abstract

An integrated circuit having an apparatus for automatically adjusting noise immunity is disclosed. The integrated circuit includes multiple functional logic circuits, a clock generator, a group of noise monitor circuits, and a control logic circuit. The clock generator generates a clock signal to all these circuits. The noise monitor circuits are utilized to detect noise occurring in the integrated circuit. In response to any noise detected by the noise monitor circuits, the control logic circuit decreases the speed of the clock signal sent to all the circuits, especially the functional logic circuits, via a slow down signal to the clock generator. Alternatively, the control logic circuit can inform the functional logic circuits via a noise alert signal to increase the noise immunity of certain noise sensitive circuits within the functional logic circuits.

Claims

1. An integrated circuit having an apparatus for automatically adjusting noise immunity, comprising:

a plurality of functional logic circuits;

a clock generator, coupled to said plurality of functional logic circuits, for generating a clock signal to said plurality of functional logic circuits;

a noise monitor circuit for detecting noise within said integrated circuit; and

a control logic circuit, coupled to said clock generator and said noise monitor circuit, for decreasing a frequency of said clock signal sent to said plurality of functional logic circuits, in response to noise, detected by said noise monitor circuit, being above a predetermined threshold.

2. The integrated circuit according to claim 1, wherein said control logic circuit generates a slow down signal to said clock generator in response to noise, detected by said noise monitor circuit, being above said predetermined threshold.

3. The integrated circuit according to claim 1, wherein said noise monitor circuit is sensitive to at least one type of noise.

4. The integrated circuit according to claim 1, wherein said noise monitor circuit is more noise sensitive than a similar circuit in said plurality of functional logic circuits.

5. An integrated circuit having an apparatus for automatically adjusting noise immunity, comprising:

a plurality of functional logic circuits;

a noise monitor circuit for detecting noise within said integrated circuit; and

a control logic circuit, coupled to said plurality of functional logic circuits and said noise monitor circuit, for increasing a noise immunity of selective noise sensitive circuits within said plurality of functional logic circuits, in response to noise, detected by said noise monitor circuit, being above a predetermined threshold.

6. The integrated circuit according to claim 5, wherein said control logic circuit generate a noise alert signal to said plurality of functional logic circuits, in response to noise, detected by said noise monitor circuit, being above said predetermined threshold.

7. The integrated circuit according to claim 5, wherein said noise monitor circuit is sensitive to at least one type of noise.

8. The integrated circuit according to claim 5, wherein said noise monitor circuit is more noise sensitive than a similar circuit in said plurality of functional logic circuits.

9. The integrated circuit according to claim 5, wherein some of said plurality of functional logic circuits are domino circuit having a feedback control.

10. A method for automatically adjusting noise immunity of an integrated circuit, said method comprising the steps of:

generating a clock signal to a plurality of functional logic circuits within said integrated circuit;

detecting noise within said integrated circuit; and

in response to detected noise above a predetermined threshold, decreasing a frequency of said clock signal sent to said plurality of functional logic circuits by generating a slow down signal to a clock generator.

11. The method according to claim 10, wherein said detecting step is performed by a noise monitor circuit that is sensitive to at least one type of noise.