Signal acquisition system utilizing ultra-wide time range time base

• US 5,243,343 A
• Filed: 12/03/1990
• Issued: 09/07/1993
• Est. Priority Date: 12/03/1990
• Status: Expired due to Term

• Current Assignee: Mentor Graphics Corporation (Siemens AG)
• Original Assignee: Zeelan Technology, Inc.
• Inventors: Moriyasu, Hiro
• Primary Examiner(s): Logan, Sharon D.
• Application Number:
  US07/621,620
• Time in Patent Office: 1,009 Days
• Field of Search: 341/61, 341/155, 341/118, 341/123, 341/122, 328/151, 328/13, 328/28, 324/77 R, 324/102
• US Class Current: 341/123
• CPC Class Codes: G01R 13/24 Time-base deflection circuits

Abstract

A signal acquisition system using an ultra-wide time range digitizer with variable time interval data sampling and data storage includes signal conditioning and sampling stages, a digitizing stage for generating digital representations of a signal, and a memory for storing the digital representations. Timing circuitry controls sampling and digitizing which may be varied so as to acquire signals on linear, logarithmic, or other time bases. Signal compression may be obtained by digitizing information only when a desired change rate is observed. A display allows acquired signals to be displayed in linear, logarithmic or other manner.

Claims

1. A signal acquisition system comprising:

digitizing means for generating a digital representation of a sample of an incoming signal;

timing control means for controlling operation of said digitizing means;

means for dynamically varying the rate of operation of said timing control means for allowing variable data acquisition rates; and

counter means for counting the number of samples acquired, said means for dynamically varying the rate of operation of said timing control means being operatively responsive to said counter means for varying the operation of said timing control means from a first predetermined timing sequence to a second predetermined timing sequence after a predetermined number of samples have been acquired in accordance with the first sequence, said predetermined number being greater than one.

2. A signal acquisition system according to claim 1 further comprising memory means for storing said digital representation.

3. A signal acquisition system comprising:

digitizing means for generating a digital representation of a sample of an incoming signal;

timing control means for controlling operation of said digitizing means; and

means for varying the rate of operation of said timing control means for allowing variable data acquisition rates,

wherein said digitizing means further comprises data value change detection means for comparing the data change rate of said signal and for capturing data other than during a time period when the data change rate is within a prescribed value.

4. A signal acquisition system comprising:

digitizing means for generating a digital representation of a sample of an incoming signal;

timing control means for controlling operation of said digitizing means;

means for varying the rate of operation of said timing control means for allowing variable data acquisition rates; and

stimulus means for providing a drive signal, said drive signal having a precise time correlation with the operation of the timing control means.

5. A signal acquisition system comprising:

digitizing means for generating a digital representation of a sample of an incoming signal;

timing control means for controlling operation of said digitizing means;

means for varying the rate of operation of said timing control means for allowing variable data acquisition rates; and

signal compression means to compress the signal in accordance with a logarithmic function.

6. A signal acquisition system which allows capturing of very fast time varying events and slow time varying events in a compressed contiguous data format, comprising:

digitizing means for creating a digital representation of a sample of a conditioned input signal;

memory means for storing said digital representation; and

time base means comprising a trigger, a clock and a dynamically alterable sampling rate controller for dynamically changing the sampling rate of said digitizing means after a predetermined number of said digital representations have been created, said predetermined number being greater than one.

7. A signal acquisition system according to claim 6 further comprising counter means for counting the number of samples acquired, said time base means being operatively responsive to said counter means, said memory means storing said digital representation at an address responsive to said counter means.

8. A signal acquisition system which allows capturing of very fast time varying events and slow time varying events in a compressed contiguous data format, comprising:

digitizing means for creating a digital representation of a sample of a conditioned input signal;

memory means for storing said digital representation; and

time base means comprising a trigger, a clock and a dynamically alterable sampling rate controller which is capable of changing the sampling rate,

wherein said digitizing means further comprises data value change detection means for comparing the data change rate of an input signal and for capturing data other than during a time period when the data change rate is within a prescribed value.

9. A signal acquisition system which allows capturing of very fast time varying events and slow time varying events in a compressed contiguous data format, comprising:

digitizing means for creating a digital representation of a sample of a conditioned input signal;

memory means for storing said digital representation;

time base means comprising a trigger, a clock and a dynamically alterable sampling rate controller which is capable of changing the sampling rate; and

stimulus means for providing a drive signal, said drive signal having a precise time correlation to the operation of the time base means.

10. A signal acquisition system which allows capturing of very fast time varying events and slow time varying events in a compressed contiguous data format, comprising:

digitizing means for creating a digital representation of a sample of a conditioned input signal;

memory means for storing said digital representation;

time base means comprising a trigger, a clock and a dynamically alterable sampling rate controller for dynamically changing the sampling rate of said digitizing mans after a predetermined number of said digital representations have been created said predetermined number being greater than one;

display means;

data processing means; and

bus means for interfacing said signal acquisition system with said display means and said data processing means to allow data to be displayed or processed.

11. A time domain reflectometer comprising:

digitizing means for generating a plurality of digital representations of samples of an incoming signal from a device under test;

timing control means for controlling operation of said digitizing means;

means for dynamically varying the rate of operation of said timing control means for allowing variable data acquisition rates for digitizing a first group of said plurality of digital representations at a first predetermined data acquisition spacing with respect to time and for digitizing a second group of said plurality of digital representations at a second predetermined data acquisition spacing with respect to time; and

stimulus means providing a drive signal for a device under test wherein said stimulus means has a precise time correlation or coherence with the operational start of said timing control means.

13. A time domain reflectometer in accordance with claim 11 further comprising memory means for storing said plurality of digital representations.

14. A time domain reflectometer in accordance with claim 11 wherein digital representations of said first group of equally spaced with respect to time.

15. A time domain reflectometer in accordance with claim 11 wherein digital representations of said first group are non-linearly spaced with respect to time.

12. A time domain reflectometer comprising:

digitizing means for generating a digital representation of a sample of an incoming signal from a device under test;

timing control means for controlling operation of said digitizing means;

means for varying the rate of operation of said timing control means or allowing variable data acquisition rates;

stimulus means providing a drive signal for a device under test wherein said stimulus means has a precise time correlation or coherence with the operational start of said timing control means; and

timing control delay means for providing a prescribed time delay between operation of said stimulus means and the operation of said digitizing means.

16. A signal acquisition system which allows capturing signals containing both rapidly varying and slowly varying components in a compressed contiguous data format, comprising:

digitizing means for generating a digital representation of a sample of a signal;

memory means for storing digitized data from said digitizing means;

time base means for generating a trigger synchronized to the signal;

generator means for generating a group of sampling pulses which have prescribed time relationships with the trigger wherein said digitizing means is operatively responsive to said sampling pulses; and

means for dynamically altering the frequency of a group of sampling pulses in a predetermined manner from a first set of time relationships to a second set of time relationships after at least two digital representations have been generated in accordance with the first set of time relationships.

17. A method of acquiring a signal with an ultra-wide range digitizer comprising the steps of:

generating a digital representation of a sample of the signal;

repeating said generating step at timed intervals; and

dynamically varying the intervals in a predetermined manner after at least two digital representations have been generated to provide a first plurality of digital representations generated at a first set of timed intervals and a second plurality of digital representations generated at a second set of timed intervals.

18. A method of acquiring a signal with an ultra-wide range digitizer comprising the steps of:

generating a digital representation of a sample of the signal;

storing said digital representation and a representation of the time at which said step of generating a digital representation of a sample of the signal occurred;

repeating said generating and storing steps at timed intervals; and

varying the intervals in a predetermined manner from a first interval time to a second interval time after at least two digital representations have been generated.

19. A method of acquiring a signal with an ultra-wide range digitizer comprising the steps of:

generating a digital representation of a sample of the signal;

storing said digital representation;

repeating said generating and storing steps at timed intervals;

varying the intervals in a predetermined manner from a first interval time to a second interval time after at least two digital representations have been generated; and

reconstructing the time at which a signal sample was taken based on the relative storage position of said digital representation.