Serial Bus Decoding & Triggering, Search & Navigation, and Segmented Acquisition Labs
4
3000 X-Series Oscilloscopes Advanced Training Guide
81
19
Press the
MISO
softkey; then select
D8
using the Entry knob.
20
Press the
(Back) front panel button to return to the previous menu.
21
Press the
CS
softkey; then press the
~CS
softkey; then select
D6
using
the Entry knob.
22
Press the
[Label]
front panel key to turn on the scope’s default labels.
Your scope should now be decoding the MOSI and MISO serial data lines
similar to
. However, the scope is not yet triggering on these
signals. The scope should be randomly auto triggering because the default
trigger condition is to trigger on a rising edge of channel- 1. But there are
no signals present on the channel- 1 input. Let’s now set up the scope to
trigger on a MOSI data byte equal to 0000 0011 (03
HEX
).
23
Press the
[Trigger]
front panel key; then select
Serial 1 (SPI)
using the
Entry knob.
24
Press the
Trigger Setup
softkey.
25
Press the
Bit
softkey; then turn the Entry knob to select the MSB
(left- most bit), which is Bit 0.
26
Press the
0 1 X
softkey to select
0
as the trigger logic condition for Bit
0 (MSB).
27
Press the
Bit
softkey to increment to the Bit 1 position.
28
Press the
0 1 X
softkey to select
0
for Bit 1.
29
Repeat Steps #27 and #28 until MOSI Data = 0000 0011.
Figure 56 Decoding a 4-wire SPI serial bus.
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