The three outputs 𝑥1𝑥2𝑥3 from the 8×3 priority encoder are used to provide…
2015
The three outputs 𝑥1𝑥2𝑥3 from the 8×3 priority encoder are used to provide a vector address of the form 101𝑥1𝑥2𝑥300. what is the second highest priority vector address in hexadecimal if the vector addresses are starting from the one with the highest priority?
- A.
𝐵𝐶
- B.
𝐴4
- C.
𝐵𝐷
- D.
𝐴𝐶
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Correct answer: B
Solution: Determine the second vector address when addresses are listed starting from the highest priority.
The 8→3 priority encoder outputs x1 x2 x3 as the 3-bit binary index of the highest-priority active input (values 000 to 111).
Vector address format is 101 x1 x2 x3 00.
If addresses start from the highest priority with index 0, the first address uses x1x2x3 = 000: 10100000 in binary = 0xA0.
The second-highest priority is index 1 (x1x2x3 = 001): 10100100 in binary. Convert to hex: 1010 0100 = 0xA4.
Therefore the second highest priority vector address is 0xA4.