Abstract: A digital peak and valley detector including a peak value address register, a valley value address register, a peak value data register, a valley value data register, a peak comparator for comparing the value stored in the peak value data register with value data contained in the digital signal applied to the digital peak and valley detector and for causing the greater of the two to be stored in the peak value data register while simultaneously storing the address in the peak value address register and a valley comparator for comparing the valley value contained in the valley value data register with the value data contained in the digital signal applied to the digital peak and valley detector for determining which is less and for causing the value and the address of the smaller of the two to be stored respectively in the valley value data and the valley value address registers.