Technical data

Serial Bus Decoding & Triggering, Search & Navigation, and Segmented Acquisition Labs 4
3000 X-Series Oscilloscopes Advanced Training Guide 73
You should see on your scope’s display what appears to be an un- triggered
display of two digital signals similar to Figure 50. Your scope is actually
triggering on random rising edges of channel- 1, which is the scope’s
default trigger condition. But these signals are too complex to establish a
unique trigger point using simple edge triggering. The signal being
captured by channel-1 is an I
2
C serial clock signal (SCL), and the signal
being captured by channel- 2 is an I
2
C serial data signal (SDA). Let’s first
set up the scope to intelligently decode this data stream based on the I
2
C
protocol, and then we will establish a more unique trigger point using I
2
C
triggering.
12 Press the [Serial] front key.
13 Press the Mode softkey; then select the I
2
C serial decode mode using the
Entry.
14 Press the Signals softkey and verity that SCL is defined as channel- 1,
and that SDA is defined as channel- 2 (default conditions).
15 Press the (Back) front panel button (above power switch) to return
to the previous menu.
16 Press the Addr Size softkey and verify that 7 Bit is selected.
17 Press the Lister softkey; then select to show a list of Serial 1 (I
2
C) using
the Entry knob.
Figure 50 Capturing I
2
C clock and data while triggering on an edge of the clock
(channel-1).
Back