AT4039EML
|
User Manual
17
|
P a g e
C
O
MMU
N
IC
A
T
IO
N
T
E
ST
&
ME
A
SU
R
EME
N
T
SO
LU
TI
O
N
S
error
detection
on
custom
defined
patterns.
User-defined Pattern
The custom pattern is
made up of 2 fields with
16
hexadecimal
characters each. One
must fill out both fields
with
all
32
hex
characters.
Every hex character is 4
bits wide, making up 2
PAM4 symbols; example
0xF is 1111 so in Gray-
coded PAM domain this
results in 22, assuming
the PAM levels are
denoted 0, 1, 2 and 3
Example 2: to transmit a
stair signal 0123, fill out
the
fields
with
repetitions of 1E
In the RX Pattern menu,
one can browse all the
patterns with which
error
detection
is
possible. Note that TX
and RX pattern must be
the same to acquire RX
lock and consequently
be
able
to
do
measurements. Also the
pattern polarity is very
important and makes all
the difference between
having RX PLL lock or no
lock at all. You can
ensure correct polarity
by connecting the TX-P
side of the cable to the
RX-P and the TX-N to the
RX-N. if you do not
respect this rule, you can
still invert polarity from
