Tektronix DG2020A, Руководство пользователя

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3Ć44
DG2020A, P3410, & P3420 User Manual
Operation.
Generate a clock pattern
Bottom button
Popup menu
Side button
# ##!
# !
#!
#!# # % !
.
# # !#!" # $ $ % # # "# # ! &
Sets up the configuration for the pseudo random pulse generator that uses a shift
register.
The shift register pseudo random pulse generator consists of a register with
between 1 and 32 bits and a feedback loop. This feedback loop takes the value
that is shifted out of the register, performs the exclusive OR with one or more
bits within the register, and places the result in the first bit of the register. The
position at which an exclusive OR is set is called a tap, and certain tap configura-
tions produce series that are the longest possible. The data generated by such a
configuration is called an M-series. If the number of stages in the shift register is
n, then an M-series pseudo random signal will have a length of 2
n
–1.
Create a simple register and tap setup as follows:
Register length: 3
Register value: 101
Set the tap with the Maximum Length Taps item.
Figure 3-40 shows the output for the above settings.
ÎÎÎÎÎÎÎÎ
ÎÎÎÎÎÎÎÎ
ÎÎÎÎÎÎÎÎ
ÎÎÎÎÎÎÎÎ
1 1 1 1 1 0 0 0 0
1 0 1
"#! #
$# $#
!
Figure 3Ć40: Register value and tap setting example
Shift Register Generator