Glenn F Johnson

US Patent:

6473700, Oct 29, 2002

Filed:

Mar 14, 2000

Appl. No.:

09/525208

Inventors:

David A. Holaday - Cornelius OR
Ken N. Nguyen - Beaverton OR
Glenn R. Johnson - Aloha OR

Assignee:

Tektronix, Inc. - Beaverton OR

International Classification:

G01R 1300

US Classification:

702 66, 702 67, 702 70, 702 79, 375224, 341 76

Abstract:

In a logic analyzer or similar binary signal-analyzing instrument, hardware circuitry, such as an ASIC, or other dedicated hardware, is used to perform waveform compression and summarization more rapidly than it could be done by software alone. The hardware is used to perform the compression of the data and to summarize its behavior for visual display. In one embodiment, the hardware starts from a given memory address and compares current timestamp values with final timestamp values to determine the length of the timeslice. Within the timeslice, all of the data is compared to determine whether it remains the same throughout the timeslice or whether it changes. The same approach can be used on violation data, such as glitches and setup and hold violations.

US Patent:

7634747, Dec 15, 2009

Filed:

May 17, 2007

Appl. No.:

11/749897

Inventors:

Michael S. Hagen - Vancouver WA, US
Robert J. Heath - Aloha OR, US
Glenn R. Johnson - Aloha OR, US
Kenneth R. Marti - Portland OR, US
James M. Fenton - Tigard OR, US
Jonathan D. Clem - Hillsboro OR, US

Assignee:

Tektronix, Inc. - Beaverton OR

International Classification:

G06F 17/50
G06F 9/45
G01B 11/16

US Classification:

716 4, 716 6, 356 32

Abstract:

A method of trace delay error compensation for measurements that are taken remotely from the signal source or receiver of a circuit uses data available from a computer aided design (CAD) tool to characterize electrical connections to an instrument measurement point, such as a connectorless probe, which is remote from the signal source or receiver. Extracted parameters from the CAD data are applied to signals acquired by the probe to adjust the signal timing and/or shape to more accurately represent the signal information timing at the signal source or receiver or other remote location of interest to a user. The corrected signals at the desired location may be displayed by a measurement instrument.

US Patent:

20070273693, Nov 29, 2007

Filed:

May 21, 2007

Appl. No.:

11/751541

Inventors:

Glenn JOHNSON - Aloha OR, US

Assignee:

TEKTRONIX, INC. - Beaverton OR

International Classification:

G06T 11/20

US Classification:

345440000

Abstract:

A macro-level digital data event display provides event-based views of the digital, either in the form of a state machine representation or in the form of events versus time. Events within the digital data are defined, including assigning a specific color as desired. The digital data is parsed to locate each of the defined events, to determine the number of times unique transitions between events occur, and to measure the amount of time spent within each defined event. The events may be displayed as a graph with event labels along one axis representing lines that extend along another axis representing time, with a bar that transitions between lines when one event changes to another in sequence within the digital data, the length of the bar indicating the time spent in each event. Alternatively the events may be presented graphically as graphic symbols with lines between them representing the transitions from one event to another, the color of the lines representing the number of times the particular transition occurred within the digital data.

US Patent:

45285918, Jul 9, 1985

Filed:

Aug 16, 1982

Appl. No.:

6/408349

Inventors:

Steven F. Liepe - Tualatin OR
Pierre Radochonski - Lake Oswego OR
Glenn R. Johnson - Aloha OR

Assignee:

Tektronix, Inc. - Beaverton OR

International Classification:

H04N 514

US Classification:

358160

Abstract:

A scheme for digitizing a stationary video image is disclosed. The amplitude of a video signal, representing said video image, is sampled at a plurality of points along the time axis and is compared with the count in a counter. If the amplitude equals the count at a particular point on the time axis, the count is stored in a memory in a location corresponding to said particular point. The process is repeated until a count in the counter is stored in said memory in locations corresponding to all of said plurality of points along the time axis of said video signal. If two or more counters are used, each counting from a different initial value, and if two or more corresponding comparators are used to make the above comparison, the time required to digitize said stationary video image may be reduced. Consequently, the time required for the video image to remain stationary is reduced.