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 there is not an explicit Cycle count trigger. If you wish to
trigger on the same cycle count, set Rep to 64, and use the Bas setting to scroll to
a specific cycle count.
Figure 85
Fast, hardware decoding of FlexRay frames.
Содержание 4000 X-Series
Страница 12: ...12 4000 X Series Oscilloscopes Advanced Training Guide 1 Getting Started...
Страница 156: ...156 4000 X Series Oscilloscopes Advanced Training Guide A Oscilloscope Block Diagram and Theory of Operation...
Страница 166: ...166 4000 X Series Oscilloscopes Advanced Training Guide B Oscilloscope Bandwidth Tutorial...
Страница 168: ...168 4000 X Series Oscilloscopes Advanced Training Guide C Related Keysight Literature...