Calculate the time necessary to perform a multiply using the approach described in the text (31 adders stacked vertically) if an integer is A bits wide and an adder takes B time units.

For many reasons, we would like to design multipliers that require less time. Many different approaches have been taken to accomplish this goal. In the following table, A represents the bit width of an integer, and B represents the number of time units (tu) taken to perform a step of an operation.

a. b. A (bit width) 8 64 B (time units) 4tu 8tu