Connect-Tek USB-2 Manuel d'utilisateur télécharger pdf (Page 12)

Application Note

www.tektronix.com/usb12

Debugging USB 2.0 Designs

Product designs with USB 2.0 interfaces usually contain a

wide variety of analog and digital signals, as well as parallel

and serial buses. For example, I2C and SPI buses are

commonly used for inter-integrated circuit communications in

embedded systems. For quick veriﬁcation and debugging, a

time-correlated view of all these mixed signals and buses is

required.

Test Equipment

The MSO/DPO4000B, MSO/DPO5000, DPO7000C, and

MSO/DSA/DPO70000C Series oscilloscopes provide

the feature-rich tools you need to speed the debugging

of your USB 2.0 designs. All models provide four analog

channels and optional USB 2.0 triggering and analysis. The

MSO4000B, MSO5000, and MSO70000C series Mixed Signal

Oscilloscopes also provide16 digital channels and parallel bus

triggering and analysis. See Figure 13.

These oscilloscopes, with the TDP1000 1 GHz Differential

Probe and the USB triggering and analysis application, can

trigger, decode, and search on USB 2.0 low-speed, full-speed

and high-speed buses. The oscilloscope’s serial trigger can

isolate and capture a wide range of USB 2.0 packet content,

protocol errors and data values.

In Figure 14, the oscilloscope has triggered on the ASCII text

string “zip” on the USB 2.0 high-speed bus. The decoded

bus is displayed in an Event Table format and the table can be

saved for documentation and for analysis with other software

tools.

Figure 14. MSO4104B Event Table display of high-speed USB data, triggered on the

text string “zip”.

Figure 13. MSO4104B oscilloscope with four analog channels and 16 digital channels

with digital per-channel threshold settings.

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Connect-Tek USB-2 Manuel d'utilisateur Page 12