Keysight LPDDR5, Руководство пользователя

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LPDDR5 Decoder User’s Guide 21
Troubleshooting the Decoder 5
If you still have difficulty using the decoder after trying these suggestions, please contact your
Keysight Technologies representative.
Erratic trace measurements • Do a full reset of the device under test before
beginning the measurement.
• Ensure that your device under test meets the
timing requirements of the applicable JEDEC
bus standard.
• See Capacitive loading. If the device under
test design has extremely close timing
margins, loading from probes may cause
incorrect functioning and give erratic trace
results.
• Ensure that you have sufficient cooling for the
device under test while the probes are
installed.
Capacitive loading Excessive capacitive loading can degrade
signals, resulting in incorrect capture, or
system lockup in the microprocessor. All
probes add additional capacitive loading,
as can custom probe fixtures you design for
your application. • Careful layout of your device under test can
minimize loading problems and result in better
margins for your design. This is especially
important for systems that are running at
frequencies greater than 50 MHz.
• Remove as many pin protectors, extenders, and
adapters as possible.
No decoding or incorrect
decoding This problem may be due to incorrect
synchronization, modified configuration,
incorrect connections, or a hardware
problem in the device under test. A locked
status line can cause incorrect or
incomplete decoding. • Ensure that each logic analyzer pod is
connected to the correct connector.
• There is not always a one-to-one
correspondence between analyzer pod
numbers and connector numbers. Probes must
supply address, data, and status information to
the analyzer in a predefined order.
• Check the activity indicators for status lines
locked in a high or low state.
• Check that the signals on the device under test
are routed to the connector according to the
manual for your probe.
• Verify that the required input buses have not
been modified from their default values. These
buses must remain as they are configured by
the configuration file. Do not change the
names of these labels or the bit assignments
within the labels. Some analysis probes also
require other data labels.
• Verify that storage qualification has not
excluded storage of all the needed states.
• Verify that the sampling positions are correctly
configured.
Problem Cause Recommended Solution