NANA-an integrated signal processor and record builder for the level-2 readout of asynchronous event-filtering digital pipelines

摘要

NANA implements some fast and simple processing algorithms, for use in future High Energy Physics (HEP) experiments. After the first level trigger, the data rate is sufficiently small to allow channel merging and some processing with dedicated hardware. For detectors whose signal is companded prior to digitization, the data samples need to be expanded to the original dynamic range, as further physics analysis usually deals with linear values. A 16 bit integer piece-wise polynomial approximation of the expansion function recovers the original dynamic range, without introducing significant degradation on the detector's intrinsic resolution. A 16 bit integer multiplier and adder-accumulator is accurate enough for time information extraction and for determination of the energy deposited in one channel. The time resolution is sufficient to correctly identify the bunch crossing that corresponds to a particular pulse. The energy accuracy is limited only by the detector's resolution. The extracted features carry all the information subsequently needed. The whole set of samples of a pulse can thus be replaced by a few data words. Initially aimed at the calorimetry front-end, the algorithms may be applied to any similar sampled detector signal.