Reference Host Chirp Test
NOTE. There must be three K-J pairs after chirp-K that are less than 500 µs. This is to check the response
of the device.
The response time must be less than 100 µs. You can verify this manually.
Host Chirp Test
This test examines the basic timing and voltages of both upstream and downstream ports during the speed
detection
protocol. To get the Chirp signal, hot-plug the unit under test (Host) and measure the signalling
with single ended probes on both lines. The a pplication analyzes data for the following:
Chirp Res
ponse Timing
Chirp-K and Chirp-J duration
The application analyzes data for the Chirp J/K to first SOF Time.
Monotonic Property Test
This algorithm calculates the number of monotonic violations that are present from of the start of the signal
to the end of packet (EOP). For the signal to be monotonic, the signal is checked from 15% to 85% of
the Pe ak to Peak differential signal levels or user specified levels.
Monotonicity is calculated for Rising and Falling slopes as follows:
For Rising slope, f(x) is a differential signal if,
signal is monotonic for all values of x till the last data point.
For Falling slope, f(x) is a differential signal if
for all values of x till the last data point.
TDSUSB2 Universal Serial Bus Measurements Package 185
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