Upgrade of the PreProcessor System for the ATLAS Level-1 Calorimeter Trigger

The ATLAS Level-1 Calorimeter Trigger is a hardware-based pipelined system designed to identify high-pT objects in the ATLAS calorimeters within a fixed latency of 2.5\,us. It consists of three subsystems: the PreProcessor which conditions and digitizes analogue signals and two digital processors. The majority of the PreProcessor's tasks are performed on a dense Multi-Chip Module(MCM) consisting of FADCs, a time-adjustment and digital processing ASICs, and LVDS serialisers designed and implemented in ten years old technologies. An MCM substitute, based on today's components (dual channel FADCs and FPGA), is being developed to profit from state-of-the-art electronics and to enhance the flexibility of the digital processing. Development and first test results are presented.