Design of configurable multi-mode trigger unit

•The hardware architecture of a remotely configurable multi-mode trigger unit for reflectometry application is presented.•Four modes of trigger operation are verified on Xilinx Zync-7000 SoC platform running at 100 MHz.•Pre/post trigger delay parameters can configure the output trigger at 10 ns resolution.•Trigger pattern mode can generate a pattern of 1024 triggers.•Clock jitter of 0.03% is obtained in the continuous trigger mode. Trigger mechanism plays a crucial role in the controlled triggering of events in reflectometry applications. Reflectometer configurations used for density profile measurement with multiple channels require stringent and complex trigger and timing requirements. Trigger generated by microcontroller/microprocessor fails to follow strict timing constraints. In this paper, we propose a hardware architecture of a remotely configurable multi-mode trigger unit. The proposed design consists of four modes of operation namely: single trigger mode (single trigger pulse is generated), continuous trigger mode (periodic trigger pulses are generated), trigger pattern mode (triggers are generated based on user defined pattern) and continuous trigger pattern mode (the trigger pattern is periodically generated). All these trigger modes help in reflectometry experiments. Hardware-software co-design techniques have been used for the optimized implementation of the design. The proposed multi-mode trigger unit is capable of controlled triggering for a set of n instruments and their peripherals such as data acquisition system (DAQ). A Graphical User Interface (GUI) is designed to remotely configure each of n trigger delay parameters and select modes of operation. Xilinx Zync-7000 SoC with part number XC7Z020-CLG484-1 is used to realize the design. The design is tested with 100 MHz clock and clock jitter of 0.03% is found in continuous trigger mode.