Question

Suppose we want to determine how many of the bits in a twelve-bit unsigned number are equal to zero. Implement the simplest circuit that can accomplish this task.

Answer 1

Answer:

See the picture for circuit figure.

Explanation:

First load 12 bit unsigned number on shift register and apply clock tick to increment counter from LSB bit.

Logic 1 is shifted into register to ensure counter doesn't count more than 12 bits.