ATCA-based ATLAS FTK input interface system

The first stage of the ATLAS Fast TracKer (FTK) is an ATCA-based input interface system, where hits from the entire silicon tracker must be clustered and organized into overlapping eta-phi trigger towers before being sent to the tracking processors. First, FTK Input Mezzanine cards receive hit data and perform clustering to reduce data volume. Then, the ATCA-based Data Formatter system will organize the trigger tower data, sharing data among boards over a full-mesh backplane. The board and system level performance studies and implementation details, as well as the operation experiences from the FTK full-chain testing, will be presented.