Hamming data correlator having selectable word-length

摘要

A data correlator has a selectable word length for hamming distance measurement. The correlator includes four 32-bit correlators which output a correlation result and a carry signal. The input of the four 32-bit correlators is controlled by a data select circuit, which inputs serial data to each of the four 32-bit correlators in accordance with the selected word length. When the 32-bit length is selected, the data select circuit simultaneously supplies serial data to each of the 32- bit correlators; when the 64-bit length is selected, the data select circuit effectively provides two simultaneously-performing 64-bit correlators; when the 128-bit length is selected, data select circuit streams the serial data through the four 32-bit correlators. A summation circuit preserves the carry-in signal of each 32-bit correlation in order to generate two 64-bit correlation values and one 128-bit correlation value. The data comparator also includes a CPU bus interface for sharing data on a CPU bus and a control register for automatic addressing of internal registers of the data comparator.