Bez tytulu slajdu

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Introduction to Experiment 5 Programmable PRNG
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(No Transcript)
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seed(7..4)
coeff(7..4)
seed(3..0)
coeff(3..0)
PRNG 3..0
PRNG 7..4
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0
coeff(7..4)"0000"
clk
load
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PRNG
clk
load
output
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Linear Feedback Shift Register (LFSR)
Each stage D flip-flop
? L, C(D) ?
Connection polynomial, C(D)
Length
C(D) 1 c1D c2D2 . . . cLDL
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Sj-1
Sj-2
Sj-(L-1)
Sj-L
Initial state
sL-1, sL-2, . . . , s1, s0
LSFR recursion
sj c1sj-1 ? c2sj-2 ? . . . ? cL-1sj-(L-1) ?
cLsj-L
for j ? L
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Example of LFSR
? 4, 1DD4?
Connection polynomial, C(D)
Length
C(D) 1 1?D 0?D2 0?D3 1?D4
c11
c20
c41
c30
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LFSR State Sequence
s4
s3
s2
s1
s0
s4 c1s3 ? c2s2 ? c3s1 ? c4s0 s3 ? s0