Agilent Technologies HP 1660E Series User Manual page 359

Logic Analyzer Reference
The Compare Menu
Mask field
The channel masking field is used to specify a bit, or bits in each label
that you do not want compared. This causes the corresponding bits in
all states to be ignored in the comparison. The Reference data image
itself remains unchanged on the display.
When you select the Mask field an assignment pop-up appears in which
you specify which channels are to be compared and which channels are
to be masked. A "." (period) indicates a don't compare mask for that
channel and an "*" (asterisk) indicates that channel is to be compared.
Bit Editing field
The bit editing fields are located in the center of the Reference listing
display. A bit editing field exists for every label in the display unless the
label's base is ASCII or inverse assembled symbols. The bit editing field
lets you modify the values of individual bits in the Reference image or
specify them as don't compare bits.
You access data in the Reference listing by rolling the data listing using
the knob until the data is located in the bit editing field. To enter a
desired pattern or don't compare (X) for a bit, select the field and use
the front-panel keypad.
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