24
Pattern Capture
Mode
Pattern Capture mode enables the raw bit
sequence captured by the DSO to be
captured. In order to see the behavior of a
specified sequence of bits, zoom in and out
by scrolling the mouse wheel, or using the
cursor to specify the region to be zoomed in
upon. Pattern rise/fall times pre-emphasis,
post-emphasis, PRBS validity and VMA
(voltage modulation amplitude) can be
measured in this mode. Note, Pattern
Capture mode needs to be able to show the
full pattern for certain features of the
software to work, such as:
VMA
The voltage modulation amplitude of a
pattern displayed in mV.
PAM4
Pulse-amplitude modulation (PAM4) is a
form of signal modulation where the
message information is encoded to one of 4
amplitude levels. Unlike NRZ which varies
between 2 amplitude levels indicating zero
and one, PAM 4 varies between 4 amplitude
levels where one symbol corresponds to a
value in the range zero to three. This leads to
double the bit rate for the same baud rate as
NRZ.
To unlock the PAM4 measurement library,
choose PAM4 as the signal type.
Voltage RMS
The voltage RMS measurement can be
captured without Pattern or Eye Lock, and
can be used to determine noise floor, which
is then entered in the Configuration/
Advanced Menu for De-Embedding the
intrinsic noise from the setup.
Some of the measurements (Min, Max, One,
Zero, Peak to Peak, Eye Amplitude, Eye
Height, Eye Width, Eye Height BER, Eye Width
BER and VEC) are applicable in PAM4 mode.
