Bus decoding and triggering on digitally down-converted data in test and measurement instruments

Abstract

The present invention relates to bus decoding and triggering of digital down-converted data in a test and measurement instrument. The test and measurement instrument includes: a digital down-converter configured to receive a bus signal and output in-phase and quadrature-phase baseband component waveform data; a trace generator configured to receive in-phase and quadrature-phase baseband component waveform data and generate at least one radio frequency versus time trace; a decoder configured to receive the at least one radio frequency versus time trace and decode the bus signal based on the at least one radio frequency versus time trace and a wireless modulation scheme; and a trigger configured to capture at least a portion of the bus signal based on the decoded bus signal.

Description

[0001] priority

[0002] This disclosure claims the benefit of U.S. Provisional Application No. 62 / 794,528, filed on January 18, 2019, entitled “BUS DECODE AND TRIGGERING ON DIGITAL DOWN CONVERTED DATA IN A TEST AND MEASUREMENT INSTRUMENT,” which is incorporated herein by reference in its entirety. Technical Field

[0003] The present disclosure relates to systems and methods related to test and measurement systems, and in particular, to test and measurement systems for decoding wirelessly received bus data and triggering on the decoded bus data. Background Art

[0004] Traditional test and measurement instruments, such as oscilloscopes, enable users to decode serial bus signals. This is done by probing the serial bus signal along with other signals necessary to decode the serial bus signal. Additional information is provided to the oscilloscope, such as information about the serial bus being acquired, including its bus type, what each channel is probing, and various other setup information.

[0005] Given setup information, conventional oscilloscopes are able to decode the actual data packets and / or data content being transmitted by the bus and present that data to the user in the form of a decoded bus display. However, this type of capability is only available for wired serial and parallel bus connections and cannot be performed on conventional oscilloscopes for signals that have wireless modulation schemes applied to them due to the complexity of wireless modulation schemes.

[0006] Embodiments of the present disclosure address these and other deficiencies of the prior art. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Aspects, features, and advantages of embodiments of the present disclosure will become apparent from the following description of embodiments with reference to the accompanying drawings, in which:

[0008] Figure 1 is a block diagram of a test and measurement instrument according to some embodiments of the present disclosure.

[0009] Figure 2 is a block diagram of another test and measurement instrument according to other embodiments of the present disclosure.

[0010] Figure 3 is a flowchart for decoding a wirelessly received bus signal according to an embodiment of the present disclosure. DETAILED DESCRIPTION

[0011] Figure 1 A block diagram of an example test and measurement instrument according to some embodiments of the present disclosure is illustrated. The test and measurement instrument may include one or more inputs 100 configured to receive one or more signals. At least one of the one or more inputs 100 receives a signal to which a wireless modulation scheme has been applied, such as a bus signal. The one or more inputs 100 may receive signals via wired or wireless inputs.

[0012] The test and measurement instrument may include one or more analog-to-digital converters 102 to convert an input bus signal into a digital bus signal. The digital bus signal may be down-converted by a digital down-converter 104 into its in-phase and quadrature-phase baseband component data.

[0013] In addition, the trace generator 106 can receive in-phase (I) and quadrature-phase (Q) baseband component information and derive or generate one or more time domain traces that can illustrate how specific characteristics of the bus signal change over time. The time domain traces can include one or more frequency versus time traces and / or in-phase baseband component data versus time and quadrature-phase baseband component data versus time. In some embodiments, a fast Fourier transform can be performed on the in-phase and quadrature-phase baseband components to generate a spectral view of the time domain data.

[0014] The radio frequency versus time trace may include, for example, an amplitude versus time trace, a frequency versus time trace, or a phase versus time trace. Additionally, the amplitude versus time trace may include a linear power versus time trace, a logarithmic power versus time trace, and / or a linear amplitude versus time trace. The trace generator 106 may generate an in-phase baseband component trace and a quadrature-phase baseband component trace.

[0015] The radio frequency versus time trace is generated using the following equation, where I is the in-phase baseband waveform data determined by the downconverter 104, and Q is the quadrature-phase baseband waveform data determined by the downconverter 104:

[0016] I = A•cos(ϕ); (1)

[0017] Q = A•sin(ϕ); (2)

[0018] Peak amplitude A = (I²+Q²) ½ ; (3)

[0019] Phase angle φ = tan⁻ 1 (Q / I); and (4)

[0020] Frequency = (Phase n+1 – Phasen ) / (360*1 / SR D ). (5)

[0021] SR in equation (5) D is the decimation rate of the incoming bus signal.

[0022] The one or more time domain traces generated by the trace generator 106 can be used by the decoder 108 to decode the serial bus signal. The decoder 108 can also receive input from the user input 110. The user input 110 can be any component that allows a user to enter information into the system, such as but not limited to a keyboard, a mouse, a joystick, or any other connected component. The input from the user input 110 can be received by wire or wirelessly. The input from the user input 110 can include information about wireless modulation schemes, such as phase shift keying, frequency shift keying, frequency modulation, etc.

[0023] The decoder 108 can use one or more traces generated by the trace generator 106 and the user input to decode the serial bus signal into decoded data. The decoded data can be, for example, a binary signal. Based on the wireless modulation scheme information received at the user input 110, the decoder 108 can set one or more thresholds for determining the binary signal. In some embodiments, the one or more thresholds are set by the user through the user input 110, rather than being determined by the wireless modulation scheme.

[0024] For example, using a frequency versus time trace, a threshold may be set at a particular frequency. Any frequency above the threshold frequency in the frequency versus time trace is decoded as a binary value of 1, and anything below that frequency is decoded as a binary value of 0. However, depending on the wireless modulation scheme and the threshold identified by the user, the threshold may be set based on the phase, amplitude, etc. of the signal, and is not limited to frequency.

[0025] In some embodiments, more than one threshold value may be set. For example, if three threshold values ​​are used, any value below two threshold values ​​may be decoded as 00, any value between the first and second threshold values ​​may be decoded as 01, any value between the second and third threshold values ​​may be decoded as 10, and any value above the third threshold value may be decoded as 11. Embodiments of the present disclosure are not limited to a single threshold value, and any number of threshold values ​​may be used as desired based on input from a user.

[0026] The trigger 112 may search the decoded data for a particular binary pattern and then trigger the capture of the decoded data upon detection of the particular binary pattern. A user may select a particular binary pattern to be used as a trigger via the user input 110. Once the decoded data is captured, the test and measurement instrument may then further process the data, such as performing additional measurements and analysis, or displaying the data on the display 114, or the trigger 112 may instruct the memory 116 to store the decoded data.

[0027] Similar to Figure 1 , Figure 2 The test and measurement instrument of the present invention may include one or more inputs 200 to receive a modulated bus signal that has been modulated based on a wireless modulation scheme. The modulated bus signal may be digitized by an analog-to-digital converter 202. A trigger 204 may include, for example, a hardware trigger that may be configured to trigger on an edge of an input signal or a clock signal. When the trigger 204 detects an edge, the modulated bus signal may be captured. In some embodiments, the trigger 204 may be triggered when a radio frequency signal is detected.

[0028] Similar to the above Figure 1 As discussed, the digitized signal may be down-converted in digital down-converter 206 to its in-phase (I) and quadrature-phase (Q) baseband component data.

[0029] Trace generator 208 is similar to trace generator 106 and can receive in-phase and quadrature-phase baseband component waveform data and derive one or more time domain traces, which, as described above, can illustrate how certain characteristics of the bus signal change over time, such as discussed above with respect to trace generator 106.

[0030] The one or more time domain traces generated by trace generator 208 may be used by decoder 210 to decode the serial bus signal, which may receive input from user input 212 similar to user input 110 .

[0031] Similar to what discussed above, decoder 210 can then use one or more traces generated by trace generator 208 and user input to decode the modulated serial bus signal into decoded data. The decoded data can be, for example, a binary signal. The decoded data can be sent to searcher 214, which can search for a specific binary pattern. As described above, the specific binary pattern can be provided by the user in user input 212. If the specific binary pattern is found in the captured waveform, searcher 214 can accept the waveform and transmit the waveform so that it is stored in memory 216, transferred to display 218 or transferred to some other components, such as one or more processors, for further processing. However, if the specific binary pattern is not found in the captured waveform, searcher 214 rejects and does not store the captured waveform.

[0032] In some embodiments, downconverter 206, trace generator 208, decoder 210, and searcher 214 may each be included in one or more processors (not shown). The one or more processors may store instructions, such as in memory 216, to perform the functions discussed above with respect to downconverter 206, trace generator 208, decoder 210, and searcher 214.

[0033] Figure 3 Illustration for use Figure 1 and Figure 2 A flowchart of decoding a bus signal that has been modulated based on a wireless modulation scheme according to any of the embodiments shown in FIG.

[0034] Initially, in operation 300, the modulated bus signal that has been digitized is down-converted into in-phase (I) and quadrature-phase (Q) baseband component waveform data. In operation 302, one or more time domain traces may be generated using the in-phase and quadrature-phase baseband component waveform data. For example, as described above, the one or more radio frequency versus time traces may include frequency versus time, phase versus time, or amplitude versus time. The time domain traces may also include in-phase and quadrature-phase baseband component information versus time traces.

[0035] Using the received wireless modulation scheme, operation 304 decodes the modulated bus signal based on the time domain trace generated in operation 302. For example, one or more thresholds may be set for the time domain trace to decode the bus signal into a binary signal. For a radio frequency versus time trace, the threshold may be a frequency, phase, or amplitude threshold that is compared to the trace to determine whether to decode the bus signal into a binary component.

[0036] When the bus signal is decoded, in operation 306, a capture device such as trigger 112 or searcher 214 can determine whether one or more trigger events are present in the decoded signal. For example, trigger 112 or searcher 214 can determine whether a particular bit stream is present in the decoded signal. If a trigger event is present, the decoded bus signal can be captured and stored in a memory, displayed, or further processed by a test and measurement instrument, such as Figure 1 and Figure 2 As shown in and described above. Figure 2 In an embodiment, if the searcher 214 does not locate a trigger event, the searcher 214 may discard the decoded bus signal.

[0037] In each of the embodiments discussed above, decoding of the bus signal may continue on a periodic or continuous basis. That is, a large portion of the bus signal may be captured and then decoded, or the bus signal may be continuously decoded and analyzed for trigger events as it is received.

[0038] Aspects of the present disclosure may be operated on specially created hardware, firmware, digital signal processors, or on a specially programmed computer including a processor operating according to programming instructions. The term controller or processor as used herein is intended to include microprocessors, microcomputers, application specific integrated circuits (ASICs), and dedicated hardware controllers. One or more aspects of the present disclosure may be embodied in computer-usable data and computer-executable instructions executed by one or more computers (including monitoring modules) or other devices, such as in one or more program modules. Typically, program modules include routines, programs, objects, components, data structures, etc., which, when executed by a processor in a computer or other device, perform specific tasks or implement specific abstract data types. Computer executable instructions may be stored on a computer-readable storage medium, such as a hard disk, an optical disk, a removable storage medium, a solid-state memory, a random access memory (RAM), etc. As will be appreciated by those skilled in the art, the functionality of the program modules may be combined or distributed as desired in various aspects. In addition, functionality may be embodied in whole or in part in firmware or hardware equivalents, such as integrated circuits, FPGAs, and the like. Certain data structures may be used to more efficiently implement one or more aspects of the present disclosure, and such data structures are contemplated within the scope of the computer-executable instructions and computer-usable data described herein.

[0039] In some cases, the disclosed aspects may be implemented in hardware, firmware, software, or any combination thereof. The disclosed aspects may also be implemented as instructions carried by or stored on one or more computer-readable storage media, which may be read and executed by one or more processors. Such instructions may be referred to as computer program products. Computer-readable media as discussed herein means any medium that may be accessed by a computing device. By way of example and not limitation, computer-readable media may include computer storage media and communication media.

[0040] Computer storage media refers to any medium that can be used to store computer-readable information. By way of example and not limitation, computer storage media may include RAM, ROM, electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technology, compact disk read-only memory (CD-ROM), digital video disk (DVD), or other optical disk storage, magnetic cassettes, magnetic tape, magnetic disk storage or other magnetic storage devices, and any other volatile or non-volatile, removable or non-removable media implemented in any technology. Computer storage media excludes the signal itself and the transitory form of signal transmission.

[0041] Communication media refers to any medium that can be used for communication of computer-readable information. By way of example and not limitation, communication media may include coaxial cables, fiber optic cables, air, or any other medium suitable for communication of electrical, optical, radio frequency (RF), infrared, acoustic or other types of signals.

[0042] Example

[0043] Illustrative examples of the technology disclosed herein are provided below. Embodiments of the technology may include any one or more of the examples described below and any combination thereof.

[0044] Example 1 is a test and measurement instrument, comprising: a digital downconverter, which is configured to receive a modulated bus signal that has been modulated based on a wireless modulation scheme and output in-phase and quadrature-phase baseband component waveform data; a trace generator, which is configured to receive the in-phase and quadrature-phase baseband component waveform data and generate one or more traces, wherein the one or more traces include a trace of radio frequency versus time or a trace of in-phase and quadrature versus time; a decoder, which is configured to decode the modulated bus signal based on the one or more traces and the wireless modulation scheme; and a capture device, which is configured to capture the modulated bus signal based on the decoded bus signal.

[0045] Example 2 is the test and measurement instrument of Example 1, wherein the decoder is configured to decode the bus signal based on the one or more traces by the following steps: determining at least one threshold value, and decoding the bus signal into a binary signal by comparing the one or more traces with the at least one threshold value.

[0046] Example 3 is the test and measurement instrument of Example 2, further comprising a user input configured to receive the at least one threshold value.

[0047] Example 4 is the test and measurement instrument of Example 2, wherein the at least one threshold is determined based on the wireless modulation scheme.

[0048] Example 5 is a test and measurement instrument of any one of Examples 1 to 4, wherein the capture device includes one or more processors configured to receive a decoded bus signal, search for a trigger event in the decoded bus signal, reject the modulated bus signal and capture a new modulated bus signal if the trigger event does not occur in the decoded bus signal, and capture the modulated bus signal if the trigger event occurs in the decoded bus signal.

[0049] Example 6 is the test and measurement instrument of any one of Examples 1 to 5, wherein the radio frequency versus time trace comprises at least one of: an amplitude versus time trace, a frequency versus time trace, and a phase versus time trace.

[0050] Example 7 is the test and measurement instrument of Example 6, wherein the amplitude versus time trace comprises at least one of: a linear power versus time trace, a logarithmic power versus time trace, and a linear amplitude versus time trace.

[0051] Example 8 is the test and measurement instrument of any one of Examples 1 to 7, wherein the capture device is further configured to detect whether an event is present in the decoded bus signal, and to capture the modulated bus signal when the event is detected.

[0052] Example 9 is a method for decoding a wirelessly received bus signal, comprising: down-converting the bus signal into in-phase and quadrature-phase baseband component waveform data; generating at least one time domain trace based on the in-phase and quadrature-phase baseband component waveform data; decoding the bus signal into decoded data based on the at least one time domain trace and a wireless modulation scheme; detecting an event in the decoded bus signal; and when an event is detected, capturing at least a portion of the decoded bus signal.

[0053] Example 10 is the method of Example 9, wherein decoding the bus signal comprises determining at least one threshold, and decoding the bus signal into a binary signal by comparing the at least one time domain trace to the at least one threshold.

[0054] Example 11 is the method of Example 10, further comprising receiving the at least one threshold from a user input.

[0055] Example 12 is the method of Example 10, wherein the at least one threshold is determined based on the wireless modulation scheme.

[0056] Example 13 is the method of any of Examples 9 to 12, further comprising: if no event is detected, rejecting the portion of the decoded bus signal and capturing a new bus signal.

[0057] Example 14 is the method of any one of Examples 9 to 13, wherein the at least one time domain trace comprises a radio frequency versus time trace, which includes an amplitude versus time trace, a frequency versus time trace, and a phase versus time trace.

[0058] Example 15 is the method of Example 14, wherein the amplitude versus time trace comprises at least one of: a linear power versus time trace, a logarithmic power versus time trace, and a linear amplitude versus time trace.

[0059] Example 16 is one or more computer-readable storage media including instructions that, when executed by one or more processors of a test and measurement instrument, cause the test and measurement instrument to: down-convert a wirelessly received bus signal into in-phase and quadrature-phase baseband component waveform data; generate at least one trace based on the in-phase and quadrature-phase baseband component waveform data; decode the bus signal into decoded data based on the trace and a wireless modulation scheme; determine whether an event exists in the decoded bus signal; and when an event is detected, store the decoded bus signal, and when no event is detected, reject the decoded bus signal.

[0060] Example 17 is the one or more computer-readable storage media of Example 16, wherein decoding the bus signal comprises: determining at least one threshold value, and decoding the bus signal into a binary signal by comparing the trace to the at least one threshold value.

[0061] Example 18 is one or more computer-readable storage media of any of Examples 16 or 17, wherein at least one trace includes at least one of: an amplitude versus time trace, a frequency versus time trace, a phase versus time trace, an in-phase baseband component versus time trace, and an orthogonal-phase baseband component versus time trace.

[0062] Example 19 is one or more computer-readable storage media of Example 18, wherein the amplitude versus time trace comprises at least one of: a linear power versus time trace, a logarithmic power versus time trace, and a linear amplitude versus time trace.

[0063] The previously described versions of the disclosed subject matter have many advantages that have been described or will be apparent to those of ordinary skill in the art. Even so, not all versions of the disclosed apparatus, system or method require these advantages or features.

[0064] In addition, this written description refers to specific features. It should be understood that the disclosure in this description includes all possible combinations of those specific features. Where a specific feature is disclosed in the context of a particular aspect or example, the feature may also be used in the context of other aspects or examples to the extent possible.

[0065] Furthermore, when a method having two or more defined steps or operations is referred to in the present application, the defined steps or operations may be performed in any order or simultaneously, unless the context excludes those possibilities.

[0066] Although particular examples of the present invention have been shown and described for purposes of illustration, it will be appreciated that various modifications may be made without departing from the spirit and scope of the invention. Accordingly, the present invention should not be limited except as in the appended claims.

Claims

1. A test and measurement instrument comprising: a digital down converter configured to receive a modulated bus signal that has been modulated based on a wireless modulation scheme and output in-phase and quadrature-phase baseband component waveform data; a trace generator configured to receive the in-phase and quadrature-phase baseband component waveform data and generate one or more traces, the one or more traces comprising a radio frequency versus time trace or an in-phase and quadrature versus time trace; a decoder configured to decode a modulated bus signal based on the one or more traces and a wireless modulation scheme; as well as a capture device configured to capture the modulated bus signal based on the decoded bus signal, Therein, the decoder is configured to decode the bus signal based on the one or more traces by the following steps: determining at least one threshold, and decoding the bus signal into a binary signal by comparing the one or more traces with the at least one threshold. 2 . The test and measurement instrument of claim 1 , further comprising a user input configured to receive the at least one threshold value.

3. The test and measurement instrument of claim 1, wherein: The at least one threshold is determined based on the wireless modulation scheme.

4. The test and measurement instrument of claim 1, wherein: The capture device includes one or more processors configured to receive a decoded bus signal, search for a trigger event in the decoded bus signal, reject the modulated bus signal and capture a new modulated bus signal if the trigger event does not occur in the decoded bus signal, and capture the modulated bus signal if the trigger event occurs in the decoded bus signal.

5. The test and measurement instrument of claim 1, wherein: The radio frequency versus time trace includes at least one of: an amplitude versus time trace, a frequency versus time trace, and a phase versus time trace.

6. The test and measurement instrument of claim 5, wherein: The amplitude versus time trace includes at least one of: a linear power versus time trace, a logarithmic power versus time trace, and a linear amplitude versus time trace.

7. The test and measurement instrument of claim 1, wherein: The capture device is further configured to detect whether an event exists in the decoded bus signal and to capture the modulated bus signal when the event is detected.

8. A method for decoding a wirelessly received bus signal, comprising: down-converting the bus signal into in-phase and quadrature-phase baseband component waveform data; generating at least one time domain trace based on the in-phase and quadrature-phase baseband component waveform data; decoding the bus signal into decoded data based on the at least one time domain trace and the wireless modulation scheme; detecting events in the decoded bus signal; as well as When an event is detected, capturing at least a portion of the decoded bus signal, Wherein, decoding the bus signal comprises: determining at least one threshold value, and decoding the bus signal into a binary signal by comparing the at least one time domain trace with the at least one threshold value.

9. The method of claim 8, further comprising receiving the at least one threshold from a user input.

10. The method according to claim 8, wherein: The at least one threshold is determined based on the wireless modulation scheme.

11. The method according to claim 8, further comprising: If no event is detected, the portion of the decoded bus signal is rejected and a new bus signal is acquired.

12. The method according to claim 8, wherein: The at least one time domain trace includes a radio frequency versus time trace including an amplitude versus time trace, a frequency versus time trace, and a phase versus time trace.

13. The method according to claim 12, wherein: The amplitude versus time trace includes at least one of: a linear power versus time trace, a logarithmic power versus time trace, and a linear amplitude versus time trace.

14. One or more computer-readable storage media comprising instructions that, when executed by one or more processors of a test and measurement instrument, cause the test and measurement instrument to: Down-converting the wirelessly received bus signal into in-phase and quadrature-phase baseband component waveform data; generating at least one trace based on the in-phase and quadrature-phase baseband component waveform data; decoding the bus signal into decoded data based on the trace and the wireless modulation scheme; determining whether an event exists in the decoded bus signal; as well as When an event is detected, storing the decoded bus signal, and when no event is detected, rejecting the decoded bus signal, Wherein, decoding the bus signal comprises: determining at least one threshold value, and decoding the bus signal into a binary signal by comparing the trace with the at least one threshold value.

15. One or more computer-readable storage media according to claim 14, wherein: The at least one trace includes at least one of: an amplitude versus time trace, a frequency versus time trace, a phase versus time trace, an in-phase baseband component versus time trace, and a quadrature-phase baseband component versus time trace.

16. One or more computer-readable storage media according to claim 15, wherein: The amplitude versus time trace includes at least one of: a linear power versus time trace, a logarithmic power versus time trace, and a linear amplitude versus time trace.

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