Abstract: An efficient data-directed scrambler is provided for processing digital signals having an unequally-weighted code. The data-directed scrambler includes inputs for receiving unequally-weighted bits of an input signal, outputs for supplying N scrambled bits of an output signal, and two or more scrambler columns connected in series between the inputs and the outputs. One or more of the scrambler columns includes a swapper cell and a digital fanout. Least significant bits in the unequally-weighted code are input to a swapper cell, and higher order bits in the unequally-weighted code are input to respective digital fanouts. In the other embodiments, an efficient data-directed scrambler is provided for processing digital signals having an equally-weighted code.

Abstract: An efficient data-directed scrambler is provided for processing digital signals having an unequally-weighted code. The data-directed scrambler includes inputs for receiving unequally-weighted bits of an input signal, outputs for supplying N scrambled bits of an output signal, and two or more scrambler columns connected in series between the inputs and the outputs. One or more of the scrambler columns includes a swapper cell and a digital fanout. Least significant bits in the unequally-weighted code are input to a swapper cell, and higher order bits in the unequally-weighted code are input to respective digital fanouts. In the other embodiments, an efficient data-directed scrambler is provided for processing digital signals having an equally-weighted code.

Abstract: Methods and apparatus are provided for processing N equally-weighted digital signals, where N is an arbitrary integer not necessarily an integer power of 2. The methods and apparatus are particularly useful in noise-shaping, mixed-signal converters. The apparatus includes a rotator for rotating the N equally-weighted digital signals in a sequence of rotator states in respective clock cycles to provide N rotated digital signals, and a data-directed scrambler having N inputs and N outputs for data-directed scrambling of the rotated digital signals to distribute the N equally-weighted digital signals to each of the N outputs of the scrambler such that the usage of the N outputs is dynamically balanced over a relatively small number of clock cycles, leading to a shaped noise spectrum.

Abstract: Methods and apparatus are provided for processing N equally-weighted digital signals, where N is an arbitrary integer not necessarily an integer power of 2. The invention is particularly useful in noise-shaping, mixed-signal converters. The apparatus includes a rotator for rotating the N equally-weighted digital signals in a sequence of rotator states in respective clock cycles to provide N rotated digital signals, and a data-directed scrambler having N inputs and N outputs for data-directed scrambling of the rotated digital signals to distribute the N equally-weighted digital signals to each of the N outputs of the scrambler such that the usage of the N outputs is dynamically balanced over a relatively small number of clock cycles, leading to a shaped noise spectrum.