456 Keysight InfiniiVision 3000T X-Series Oscilloscopes User's Guide
29 I2S Triggering and Serial Decode
 
5 For the SCLK (serial clock), WS (word select), and SDATA (serial data) signals:
a Connect an oscilloscope channel to the signal in the device under test.
b Press the SCLK, WS, or SDATA softkey; then, turn the Entry knob to select the 
channel for the signal.
c Press the corresponding Threshold softkey; then, turn the Entry knob to select 
the signal threshold voltage level.
Set the threshold levels for the SCLK, WS, and SDATA signals to the middle 
of the signals.
The threshold voltage level is used in decoding, and it will become the 
trigger level when the trigger type is set to the selected serial decode slot.
The SCLK, WS, and SDATA labels for the source channels are automatically set.
6 Press the  Back/Up key to return to the Serial Decode Menu.
7 Press the Bus Config softkey to open the I
2
S Bus Configuration Menu and display 
a diagram showing WS, SCLK, and SDATA signals for the currently specified 
bus configuration.
8 Press the Word Size softkey. Turn the Entry knob to match the transmitter word 
size of the device under test (from 4 to 32 bits).
9 Press the Receiver softkey. Turn the Entry knob to match the receiver word size 
of the device under test (from 4 to 32 bits).
10 Press the Alignment softkey; then, turn the Entry knob to select the desired 
alignment of the data signal (SDATA). The on-screen diagram changes with 
your selection.
Standard Alignment — MSB of data for each sample is sent first, LSB is sent last. 
The MSB appears on the SDATA line one bit clock after the edge of the WS 
transition.