AutoFocus User’s Guide
18
©1989-2018 Lauterbach GmbH
Manual Setup
This section describes a manual setup of all sampling parameters for the preprocessor. The manual setup is
applicable for the following cases:
•
Varying core/trace frequency
•
Gated trace clock
•
Low signal integrity or asymmetric clock waveforms
•
High signal skew
•
AutoFocus fails
To manually set up the sampling parameters for the preprocessor:
1.
Enable termination (
Analyzer.TERMination
ON
)
2.
Set the threshold for clock and data to VCC/2 (
Analyzer.THreshold
VCC
)
3.
Scan the clock eye (
Analyzer.TestFocusClockEye
)
Accumulate multiple scans in case of varying clock frequency
(
Analyzer.TestFocusEye /Accumulate
)
4.
Look for best threshold level (
Analyzer.ShowFocusClockEye
)
5.
Set the threshold for clock (
Analyzer.THreshold
<clk>
)
6.
Scan the data eye (
Analyzer.TestFocusEye
)
Accumulate multiple scans in case of varying clock frequency
(
Analyzer.TestFocusEye /Accumulate
)
7.
Look for best threshold level (
Analyzer.ShowFocusEye
)
8.
Set the threshold for data (
Analyzer.THreshold
<clk>
<dat>
)
9.
Scan the digital data eyes (
Analyzer.TestFocus
)
Accumulate multiple scans in case of varying clock frequency.
(
Analyzer.TestFocus /Accumulate
)
10.
Define potential sampling points (
Analyzer.ShowFocus
)
11.
Set the sampling points - one for each trace signal (
Analyzer.SAMPLE
).
Alternatively, double-click in the
Analyzer.ShowFocus
window to set the sampling points.
12.
Test the trace port (
Analyzer.TestFocus
)
If you want to go deeper into the subject please see the information given in chapter
Advanced Check
.
More than one data eye could be shown in the
Analyzer.ShowFocus
window at
higher trace port speeds. It can be essential to select the correct data eye in case
of gated clocking. You should set all sampling points to the next visible data eye
and test again, if the trace port test fails at #12.
