Technical data

Serial Bus Decoding & Triggering, Search & Navigation, and Segmented Acquisition Labs 4
4000 X-Series Oscilloscopes Advanced Training Guide 127
Note that your scope should still be triggering on random edge crossings of
channel- 1. Let's now set up the scope to trigger when it detects a frame
with ID=1.
12 Press the [Trigger] front panel key; then select Serial 1 (FlexRay).
13 Tap the Trigger on: softkey; then select Frame.
14 Tap the Frames softkey.
15 Set Frame ID to 1.
We are now triggering on Frame ID=1, all cycles. Note how the Cycle count
(yellow, two digit number) flips quickly from 00 to 01, in sync with the
corresponding data (white) and FCRC (blue).
To provide more insight on the Rep and Bas settings, imagine a more
complex FlexRay implementation with 64 static frames and 64 cycles.
Setting rep to 8 and Bas to 0 would allow you to trigger on Frame ID 1,
cycles 0, 8, 16, 24… If you set rep to 8 and Bas to 2, you will trigger on
Frame ID 1, cycles 2, 10, 18, 26… Many topology designers utilize this
method to multiplex signals that do not require updates on each cycle,
allowing Frame ID to be utilized for many different systems. This is why
Figure 85 Fast, hardware decoding of FlexRay frames.