Abstract: An add-compare-select-offset device including first and second adders for generating values a and b respectively equal to the sum of first previous state and branch metrics and to the sum of second previous state and branch metrics, a calculation block for providing the greatest of values a and b on a first output and generating an adjustment value on a second output; and, a third adder for generating a current state metric equal to the sum of the outputs of the calculation block, wherein the adders perform additions without keeping the carry so that the current state metric and intermediary values a and b comprise the same number of bits as the first and second previous state metrics.

Abstract: A LIFO type data storage device of 2N depth, N being an integer, includes two random access memories each having at least 2N−1 locations for storing data. A controller controls the reading and writing of data in one or the other of the two memories, or the direct transmission of data to multiplexing means. Outputs of the two memories are also connected to the multiplexing means and the output of the device is connected to the multiplexing means via a sampler.

Abstract: A device for implementing a function of add-compare-select type in an error correction code decoder, having first and second adders for adding, respectively for first and second branches, branch metric values, intermediate value of former state metrics, and values of former state metric offset, thus forming first and second values of present state metrics; a comparator, coupled to the first and second adders, for selecting the highest value from among the first and second values; circuitry for determining a digital value of present state metric offset including a single bit, based on the first and second values.