Specifications

7-33
Softkey Menu Descriptions
Input & Eye Menu
Toggles the data input termination level between ground and
−2V.
Toggles the clock input termination between ground and −2V.
Initiates an attempt to align the data input delay so that the Error
Detector samples in the center of the data input eye. While
alignment is in progress the right-menu changes to give an
softkey. The user may press this key at any
time and the alignment will abort and return the instrument to its
original state.
To Perform Clock-to-Data Alignment
Select , to view eye results. Now
select , then press the softkey.
The eye width is displayed in the Data eye results window.
Initiates an attempt to set the zero-to-one threshold to the mid-
point of the incoming data eye on the vertical, voltage axis.
To Select Automatic Center
In this mode it is recommended to first set the “EYE EDGE
THRESHOLD” to a known BER (bit error ratio) threshold,
perform a clock-to-data alignment and then select Automatic
Center mode.
To Perform Automatic Center
Select ,thenpressthe
softkey. The eye height is displayed, and the 0/1 manual-mode
threshold level given plus other data eye results.
Sets the threshold used by the clock/data align feature in the
search for the edges of the data eye. The range of valid values is
1.0E−1 through 1.0E−7.
For example to enter a BER threshold of 1.5E−02: Press the
softkey. Enter 1.5 using the numeric
keypad, then press the right-menu softkey. Finish entering
the number (2) using the numeric keypad then press .
The Eye Edge Threshold is used by the clock-to-data align and
0/1 threshold center functions to define the edges of the data
input eye.
DAT TRM 0V -2V
CLK TRM 0V -2V
CLK-DAT ALIGN
ABORT ALIGN
result pages
EYE RESULTS
input & eye
CLK-DAT ALIGN
0/1 THR CENTER
input & eye
0/1 THR CENTER
EYE EDG THRSHLD
EYE EDG THRSHLD
e
ENTER