Devices and methods of reducing quantization noise using a pyramid stream encoder are generally described. Groups of D digital symbols are iteratively computed for a digital signal such that each group of symbols minimizes a norm of a weighted residue vector. The weighted residue vector is formed by applying predetermined weighting coefficients to components of a residue vector. Each component is a difference between a sample of the digital signal and a linear combination of different groups of digital symbols with predefined filter coefficients. The norm of the weighted residue vector evaluated at a rate D times slower than a sampling rate of an output signal. The groups of D digital symbols are provided as the output signal.

In accordance with an embodiment, a system includes: a primary device configured to be connected to at least one secondary device via serial bus having a data wire and a clock wire. The primary device is configured to: provide a clock signal on the clock wire; and transmit a frame comprising control bits on the serial bus, wherein a number of control bits transmitted on the serial bus at at least one location of the frame indicates a format of the frame.

Systems, methods, and other embodiments associated with converting an input signal into an output signal with a different sampling rate. In one embodiment, an apparatus includes a feedforward circuit configured to receive the input signal comprised of discrete data samples with the first sampling rate and to generate a first intermediate value based, at least in part, on a feedforward coefficient and the input signal. The apparatus includes a feedback circuit configured to generate a second intermediate value that is based, at least in part, on a feedback coefficient and a predetermined number of previous samples of the output signal. The apparatus includes a signal combiner configured to combine the first intermediate value and the second intermediate value together to interpolate a data sample of the output signal at the second sampling rate. The output signal is a converted form of the input signal at the second sampling rate.