The minimum number of D flip-flops needed to design a mod-258 counter is
2011
The minimum number of D flip-flops needed to design a mod-258 counter is
- A.
9
- B.
8
- C.
512
- D.
258
Attempted by 217 students.
Show answer & explanation
Correct answer: A
Key idea: find the smallest integer n such that 2^n ≥ 258.
Check n = 8: 2^8 = 256, which is less than 258.
Check n = 9: 2^9 = 512, which is greater than or equal to 258.
Conclusion: the minimum number of D flip-flops required is 9. (There will be 512 − 258 = 254 unused states that should be handled in the design.)
A video solution is available for this question — log in and enroll to watch it.