Connect-Tek USB-16 Manual de usuario descargar pdf (Pagina 28)

Host High Speed Electrical Test Procedure Revision 1.4

9. Click Enumerate Bus using the High Speed Electrical Test Tool and capture the CHIRP

handshake as in the following figure.

Note: Instead of enumerating the device, an alternative method to generate the chirp signal, is

to disconnect and reconnect the unit under test (device) to the port.

Figure 16: High Speed Chirp

Host Chirp Response

10. The application measures the host’s Chirp response timing (TWTRSTFS) EL_33.. This is the

time between the device’s de-assertion of Chirp-K and the start of alternate Chirp-K and Chirp-

J sent by the host. The timing should be ≤ 100 μs.

11. The application measures (EL_34) and record the durations of the individual Chirp-K and

Chirp-J states and verifies that both are between 40 μs ≤ TDCHBIT ≤ 60 μs (EL_31).

12. Click Chirp on the application and select Host option EL_35. Click Run.

13. Unplug the known good device and then reattach it.

14. Ensure the oscilloscope trigger is armed.

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Connect-Tek USB-16 Manual de usuario Pagina 28