Agilent Technologies DSO-X 4022A, Руководство пользователя

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I2C/SPI Triggering and Serial Decode
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Agilent InfiniiVision 4000 X-Series Oscilloscopes User's Guide 427
In the SPI Chip Select Menu:
a Press the Frame by softkey to select a framing signal that the
oscilloscope will use for determining which clock edge is the first
clock edge in the serial stream.
You can set the oscilloscope to trigger during a high chip select ( CS ),
a low chip select ( ~CS ), or after a Timeout period during which the
clock signal has been idle.
• If the framing signal is set to
CS
(or
~CS
), the first clock edge as
defined, rising or falling, seen after the CS (or ~CS ) signal
transitions from low to high (or high to low) is the first clock in
the serial stream.
Chip Select — Press the CS or ~CS softkey; then, turn the Entry
knob to select the channel that is connected to the SPI frame line.
The label (~CS or CS) for the source channel is automatically set.
The data pattern and the clock transition must occur during the
time when the framing signal is valid. The framing signal must be
valid for the entire data pattern.