Command Dictionary Diagnose Failures
FastScan and FlexTest Reference Manual, V8.6_4 2-221
The primary use for this command is for diagnostics.
If you suspect that a scan chain defect is causing a scan cell to remain at a constant
state, use the -Chain switch. The diagnosis then identifies the scan cell closest to
the scan-in pin that will not achieve both a 0 and 1 state. The analysis assumes that
the scan cells closer to the scan-out pin will be able to capture both a 0 and 1 value
and that the tool will successfully observe them because the state does not have to
propagate through the defective scan cell. The diagnosis reports the scan cell that
is most likely to contain the defect and gives the name and ID number of its
master element. If no scan chains appear to have a fixed value scan cell, the
command reports a message to that effect.
Arguments
•failure_filename
A required string that specifies the name of the file, generated by an ATE
tester, that contains the failing pattern identifications.
•-Last pattern_number | pattern_name
An optional switch that specifies the line number or name of the pattern
identifier in the failure_filename at which the tester truncated the test. For
FastScan, pattern_number is an integer pair and pattern_name is a string
generated by using the -tag tag_name switch with the Save Patterns command
(which specifies a prefix for all pattern names). For example, pattern_name =
tag_name_1, tag_name_2, etc.
If you do not specify the -Last switch, the tool assumes that failure_filename
includes all the failing patterns.
•-Output report_filename
An optional switch and string pair that specifies the name of the file to which
you want to write the diagnostic report.
!
Caution
When using ATE failure data, the ATE must finish collecting fail
data on the complete pattern boundary. This is because the
Diagnose Failures command assumes that any cells or primary
outputs not included in the failing patterns file passed the testing.
If the tester did not finish, the diagnosis summary report may yield
inconclusive or unreliable results.