Keysight Technologies DSO-X 2014A, User Manual

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354 Keysight InfiniiVision 2000 X-Series Oscilloscopes User's Guide
24
I2C/SPI Triggering and Serial Decode
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.
• If the framing signal is set to Timeout , the oscilloscope generates it's own
internal framing signal after it sees inactivity on the serial clock line.