A 32 bit adder is formed by cascading 4 bit CLA adder. The gate delays…
2017
A 32 bit adder is formed by cascading 4 bit CLA adder. The gate delays (latency) for getting the sum bits is
- A.
16
- B.
18
- C.
17
- D.
19
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Correct answer: C
A 32-bit adder using cascaded 4-bit CLA adders requires eight blocks. Each inter-block carry propagation adds 2 gate delays, totaling 7*2=14 for seven connections. Sum bits within each block take an additional 3 gate delays after carry-in is resolved. Thus, total latency is 14+3=17 gate delays.