hardware circular buffer definition programming, hardware
digital signal processors which support hardware circular buffers automatically generate and increment pointers
accesses which wrap to the beginning of the buffer
when its end is reached, thus saving the time and instructions otherwise needed to ensure that the address pointer stays within the boundary of the buffer, and speeding the execution of repetitive DSP algorithms.
Digital Signal Processor For Digital Audio Applications (http://analog.com/publications/documentation/21065L_Audio_Tutorial.PDF).