DAQ platform based on SoC-FPGA for high resolution time stamping in cosmic ray detection

Accurate timing in cosmic ray detection is critical for reconstruction of events from multiple scattered detectors. Since most of the detectors dedicated to study cosmic rays generate continuous analog signals, a precise timing depends on the sampling rate and the subsequent triggering system operating on the generated digital data stream. In this paper, a data acquisition platform based on a fully programmable System-On-Chip (SoC) and a high-speed analog to digital converter, able to manage 8-bit data resolution, 500MHz sampling rate and GPS connection for data synchronization is presented. The SoC is a ZYNQ 7000 device with a Field Programmable Gate Array (FPGA) and a dual core ARM processor embedded on a single chip. The system achieves 2 ns time resolution and is also able to increase data amplitude resolution through oversampling and can simultaneously generate a real time histogram of the incoming data. The platform has an embedded high voltage power supply control with temperature and pressure compensation for optimal and stable operation of different detectors. While the time critical activities are handled and carried out by the FPGA, software running on the dual core ARM processor with a real time operating system (FreeRTOS) provides Ethernet connection for remote control of the platform.