Operating instructions

University of Saskatchewan
Electrical Engineering Laboratory Equipment Manual
Logic Analyzers
Logic analyzers are specialized equipment that are very similar to oscilloscopes,
except that they are tailored to analyze and display digital signals only. They are, in
essence, simply multiple channel oscilloscopes that only determine whether a channel
is logic high or low. Their power comes from the fact that they can be set to trigger off
of multiple events on different channels. This feature is extremely useful. As an
example, say that you are troubleshooting the operation of a microprocessor. If you
know and can verify that the microprocessor works properly up to a certain point or
event (but not after that), then you can set the logic analyzer to trigger from that specific
event. That becomes the t = 0 point for the display (much like an oscilloscope). The
logic analyzer will trigger on this last known ―good‖ point of the microprocessor and then
capture data. That data will assist you in determining what is going wrong so that you
may remedy the situation.
HP 54620A 16 Channel 500 MSa/s Logic Analyzer
The pouch on top of the analyzer contains a ribbon cable that plugs into the front
panel. It has 16 leads to which 16 micro-grabbers may be attached. These micro-
grabbers do not hold onto things all that well, so care must be taken once they are
attached, as they can pop off easily. They can be directly attached onto the pins of ICs
as they will hold quite well when attached in this manner. The ground lead must be
connected to ground when performing any measurements.
Single
channel
Dual
channel
Cursors
Trace
Setup
Measure time
Save / Recall
Auto -
scale
Display
Print
Utility
Run
Stop
Single
Auto -
store
Erase
Edge
Pattern
Adv
Main
Delayed
STORAGE
HORIZONTAL
TRIGGER
CHANNEL
Delay
Time / DivSelect
Position
0 15 1 s
5 ns
Line
O I
Trigger out Ext trigger in
54620A
16 CHANNEL 500 MSa/s
HEWLETT
PACKARD
hp
Entry
LOGIC ANALYZER
Mode
On
Off
Label
INPUTS
Logic
levels