LFSR Sequence Trace: Non-Binary Pattern Verification
A 4-bit positive-edge-triggered Fibonacci Linear Feedback Shift Register (LFSR) updates its state on every LOW-to-HIGH clock transition using the feedback polynomial tap configuration D3 = Q3 XOR Q0. Five signals are shown: CLK (clock, period 2) and four state outputs Q3, Q2, Q1, and Q0. The shift register shifts right, meaning Q2 takes the value of Q3, Q1 takes Q2, and Q0 takes Q1. The initial state at time step 0 is 0001 (Q3=0, Q2=0, Q1=0, Q0=1). Trace the outputs Q3, Q2, Q1, and Q0 across all 16 time steps to verify the first 8 states of the pseudo-random sequence.
Constraints
- The LFSR is strictly positive-edge-triggered.
- The new bit shifted into
Q3is the XOR of the currentQ3andQ0values evaluated immediately before the rising clock edge. - The register shifts right:
Q3moves toQ2,Q2moves toQ1, andQ1moves toQ0.
Topics
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