Level-1 Data Driver Card of the ATLAS New Small Wheel upgrade compatible with the Phase II 1 MHz readout scheme

The Level-1 Data Driver Card (L1DDC) will be designed for the needs of the future upgrades of the innermost stations of the ATLAS end-cap muon spectrometer. The L1DDC is a high speed aggregator board capable of communicating with a large number of front-end electronics. It collects the Level-1 data along with monitoring data and transmits them to a network interface through a single bidirectional fiber link. In addition, the L1DDC board distributes trigger, time and configuration data coming from the network interface to the front-end boards. The L1DDC is fully compatible with the Phase II upgrade where the trigger rate is expected to reach 1 MHz. This paper describes the overall scheme of the data acquisition process and especially the three different L1DDC boards that will be fabricated. Moreover the L1DDC prototype-1 is also described.