Unusually high intensity ( 10**11 proton/sec ) beam is planned to be ejected for fixed targets at FAIR accelerator upto 90 GeV energy. Using this beam the FAIR-CBM experiment provides an unique high luminosity facility to measure high pT phenomena with unprecedented sensitivity exceeding by orders of magnitude that of previous experiments. Applying 1% target the expected minimum bias event rate will be in the range of GHz. In order to get a selective trigger which reduces this rate to the kHz range one needs an extremely fast algorithm. Due to the fact that the minimal read-out time for pixel detectors is about 1 microsec, one could get 1000-fold pile-up. Proton-Carbon interactions in the STS detector of CBM were simulated assuming 4 pixel and 5 strip detector (x,y) planes, a highly parallel online algorithm is proposed which could select the high pT tracks with high efficiency. The proposed mosaic-trigger system is data-driven. The recorded hits are directed toward corridors assigned to the corresponding "mosaics" in the given Si-plane. Narrow tubes are defined on a subset and an exhaustive search is performed on the full set applying content addressable memories (CAM's).

oral