User guide

• Length: This field indicates the length of the captured data. Note that the value
here does not equal the length of the pattern.
Compare Pattern File
The captured data is saved as an alternating pattern:
• Pattern A contains the expected data.
• Pattern B contains the errored data:
0s if the expected bits were also received, 1s for errored bits.
To calculate the captured pattern, XOR the bits from pattern A with the bits from
pattern B.
The pattern description contains the first error, the error count, date and time.
The name of the pattern file is ELOC_RESULT_CURRENT.ptrn for the current
capture and ELOC_RESULT_PREVIOUS.ptrn for the previous capture. These
patterns are saved under C:\<instrument model>\Pattern on the machine with the
firmware server.
The results are displayed in the window below the pattern. You can compare the
results of the Current Run with the results of the Previous Run:
• 1st Bit-Error Location:
Address of the first captured errored bit.
• Bit Error Count:
Number of all errored bits captured during the measurement.
Fast Eye Mask
Fast Eye Mask - Concepts
The Fast Eye Mask measurement is first of all meant for production and screening
tests. It allows to determine very quickly whether the eye opening seen at the
output signal of a device is within specifications, that is, within certain timing and
voltage limits.
Measuring the eye openings with an oscilloscope used to be a time-consuming
procedure. With the Fast Eye Mask measurement of the Serial BERT, pass/fail
information can be obtained within seconds.
Advanced Analysis 6
Agilent J-BERT N4903B High-Performance Serial BERT 307
Results Window