Oscilloscope persistence for digital bus signals

Patent metadata

Field	Value
Publication number	US-10983146-B2
Application number	US-201615393090-A
Country	US
Kind code	B2
Filing date	Dec 28, 2016
Priority date	Dec 28, 2016
Publication date	Apr 20, 2021
Grant date	Apr 20, 2021

Abstract

A test and measurement system is disclosed that includes an input for receiving a digital bus conducting a plurality of digital values, a display, and a memory. The memory stores hit frequencies for the digital values, and stores data indicating the digital values. The test and measurement system also includes at least one processor coupled to the display and the memory. The processor causes the display to depict the digital values and hit frequencies of the digital values by depicting persistence of the digital values over time and by depicting decay of the digital values over time.

First claim

I claim:

1. A test and measurement system comprising:
an input port structured to connect to a digital bus conducting a digital signal from a device under test;
at least one acquisition circuit coupled to the input port and configured to sample the digital signal to obtain a plurality of digital values;
a display;
a memory configured to:
store hit frequencies for each of the plurality of digital values for a plurality of time periods in hit lines and store hit frequencies for each transition between two of the plurality of digital values for the plurality of time periods in hit lines, each hit line including a label indicating either a digital value or a transition between digital values, and
store data indicating the digital value associated with each hit frequency for each time period; and

at least one processor coupled to the input port, the display, and the memory, the processor configured to determine a persistence of each the plurality of digital values over time, to determine a decay of each of the plurality of digital values over time, and to cause the display to depict the digital values and the hit frequencies of the digital values by depicting the persistence of the digital values over time and by depicting the decay of the digital values over time.

2. The test and measurement system of claim 1 , wherein the digital bus conducts each digital value as a set of parallel signals.

3. The test and measurement system of claim 1 , wherein the memory includes a plurality of hit lines, each hit line to store data indicating hit frequencies of a corresponding digital value, and a plurality of value lines to store data indicating the digital values stored in corresponding hit lines.

4. The test and measurement system of claim 3 , wherein the memory further includes an other line to store hit frequencies of digital values when a number of received digital values is in excess of a maximum number of storable digital values.

5. The test and measurement system of claim 1 , wherein the at least one processor decrements hit frequencies when corresponding digital values are not received over a specified acquisition period.

6. The test and measurement system of claim 1 , wherein the test and measurement system is a digital phosphor oscilloscope (DPO), and wherein the memory is DPO memory.

7. The test and measurement system of claim 1 , wherein the digital values are hexadecimal numbers.

8. The test and measurement system of claim 1 , wherein the at least one processor is further configured to:
determine digital value durations based on the stored hit frequencies; and
cause the display to depict digital values with value graphical items with lengths corresponding to digital value durations.

9. The test and measurement system of claim 8 , wherein the at least one processor is further configured to cause the display to depict transitions between digital values with transition graphical items, the transition graphical items selected to indicate hit frequencies for the digital values over a plurality of triggered acquisition periods.

10. A method implemented in a test and measurement system, the method comprising:
receiving, at an input port, digital values over a digital bus coupled to a device under test;
storing hit frequencies for each of the received digital values for a plurality of time periods in hit lines, each hit line of the received digital values including a label indicating the digital value in a memory;
storing hit frequencies for each transition between two of the plurality of digital values for the plurality of time periods in hit lines, each hit line for the transitions including a label indicating the transition between digital values in the memory;
storing data indicating the digital values associated with the hit frequencies received in the memory;
determining a persistence of each the plurality of digital values over time;
determining a decay of each of the plurality of digital values over time; and
displaying the digital values and hit frequencies of the digital values by depicting the persistence of each of the digital values over time and by depicting decay of each of the digital values over time.

11. The method of claim 10 , wherein displaying the digital values includes depicting digital values with value graphical items with lengths corresponding to digital value durations.

12. The method of claim 11 , wherein displaying the digital values further includes depicting transitions between digital values with transition graphical items, the transition graphical items selected to indicate hit frequencies for the digital values over a plurality of triggered acquisition periods.

13. The method of claim 10 , wherein each digital value is received as a set of parallel signals.

14. The method of claim 10 , wherein the memory is a digital phosphor oscilloscope (DPO) memory, wherein storing hit frequencies for the received digital values includes storing hit frequencies for each digital value in corresponding hit lines in the DPO memory, and wherein storing data indicating the digital values includes storing the data indicating the digital values in value lines in the DPO memory, the value lines corresponding to the hit lines.

15. A non-transitory storage medium comprising a computer program product, the computer program product including instructions that when executed by at least one processor cause the at least one processor to:
receive digital values over a digital bus coupled to a device under test;
store hit frequencies for each of the received digital values for a plurality of time periods in hit lines, each hit line of the received digital values including a label indicating the digital value in a digital phosphor oscilloscope (DPO) memory;
store hit frequencies for each transition between two of the plurality of digital values for the plurality of time periods in hit lines, each hit line for the transitions including a label indicating the transition between digital values in the digital phosphor oscilloscope (DPO) memory;
store data indicating the digital values associated with the hit frequencies received in the DPO memory;
determine a persistence of each the plurality of digital values over time;
determine a decay of each of the plurality of digital values over time; and
display the digital values and hit frequencies of the digital values on an oscilloscope display by depicting persistence of the digital values over time and by depicting decay of the digital values over time.

16. The non-transitory storage medium of claim 15 , wherein displaying the digital values includes depicting digital values with value graphical items with lengths corresponding to digital value durations.

17. The non-transitory storage medium of claim 16 , wherein displaying the digital values further includes depicting transitions between digital values with transition graphical items, the transition graphical items selected to indicate hit frequencies for the digital values over a plurality of triggered scans.

18. The non-transitory storage medium of claim 15 , wherein the instructions further cause the processor to decrement hit frequencies when corresponding digital values are not received over a specified acquisition period.

19. The non-transitory storage medium of claim 15 , wherein storing hit frequencies for the received digital values includes storing hit frequencies for each digital value in corresponding hit lines in the DPO memory, and wherein storing data indicating the digital values includes storing the data indica

Assignees

• Tektronix Inc

Inventors

• Spisak Kevin C

Classifications

• G01R13/0209 Primary

  in numerical form · CPC title

• G01R13/0227

  Controlling the intensity or colour of the display · CPC title

• G01R13/0236

  for presentation of more than one variable · CPC title