372 Agilent InfiniiVision 3000 X-Series Oscilloscopes User's Guide
24 I2C/SPI Triggering and Serial Decode
 
9 Press the CS softkey to open the SPI Chip Select Menu.
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.