Remainder Selector : A remainder selector is needed to determine the output of the 4-bit subtractor,:if the partial dividend is larger than the normalized divisor, the output of subtractor should be equal to the difference between partial dividend and normalized divisor; if not, the subtractor just pass the partial dividend through to the next iteration. (simulation results for Remainder Selector can be found here)

4_bit_controlled_subtractor: The 4_bit_controlled_subtractor is the building block of this divider, its behaviour efftets the verall performance of the divider. Each stage of 4_bit_controlled_subtractor outputs one-bit of quotient and 4-bit remainder, a total of 13 subtractors are needed to obtain a 13-bit partial quotient. Partial quotient togethe with the output of comparator are then processed by the Quotient Shifter. Simulation results of 4-bit subtractor can be found here.

Comparator: The function of comparator is to compare the final 4-bit remainder with the original divisor (unshifted) and to calibrate the quotient. Since all divisors are normalized from 8~15, it is very likely that the remainder is larger than the unshifted divisor, under such circumstances, we need to add a "one" to the end of the partial quotient to eliminate error, this is done by the comparator. Simulation result of comparator can be found here.