i = 0, i-1 = -1; $clog2(i) = 0
i = 1, i-1 = 0; $clog2(i) = 1
i = 2, i-1 = 1; $clog2(i) = 2
i = 3, i-1 = 2; $clog2(i) = 2
i = 4, i-1 = 4; $clog2(i) = 3
i = 5, i-1 = 5; $clog2(i) = 3
i = 6, i-1 = 6; $clog2(i) = 3
i = 7, i-1 = 7; $clog2(i) = 3
i = 8, i-1 = 8; $clog2(i) = 4
i = 9, i-1 = 9; $clog2(i) = 4
i = 10, i-1 = 10; $clog2(i) = 4
i = 11, i-1 = 11; $clog2(i) = 4
i = 12, i-1 = 12; $clog2(i) = 4
i = 13, i-1 = 13; $clog2(i) = 4
i = 14, i-1 = 14; $clog2(i) = 4
i = 15, i-1 = 15; $clog2(i) = 4
i = 16, i-1 = 16; $clog2(i) = 4