Circuit that multiplies 2 4-bit numbers and gives an 8-bit result.
For example, 0010 x 0010 [2 x 2] (where m3 = 0, m2 = 0, m1 = 1, m0 = 0, q3 = 0, q2 = 0, q1 = 1, q0 = 0) gives 00000100 [4] as the result.