Technical data

Serial Bus Decoding & Triggering, Search & Navigation, and Segmented Acquisition Labs 4

4000 X-Series Oscilloscopes Advanced Training Guide 83

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 Read

operation from address = 29

HEX

, following by an “acknowledge”, followed

by any data content (don’t care).

18 Press the [Trigger] front panel key; then select Serial 1 (I

C) using the

Entry knob.

19 Tap the Trigger: Start softkey; then select Frame(Start:Addr 7:Read:Ack:Data).

20 Tap the Address softkey; then set to 0x29 using the Entry knob.

21 Set the scope’s timebase to 200.0 µs/div.

You should now see stable waveform traces on your scope’s display similar

to Figure 52. The I

C frame that is near the center of the scope’s display,

which is the frame that the scope is triggering on, should be decoded as:

< 29RA FFA 80~A > or < 29RA FFA C0~A >

Figure 52 Triggering on I

C traffic.