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This paper introduces four FPGA-based designs for radiation-tolerant time-of-flight (TOF) systems for sub-atomic particles: Snapshot, Vernier, Fast-Clocking and Hybrid designs. The designs measure TOFs ranging from 0 to 240 ns and are compared based on resolution, thermal performance, FPGA I/O pin usage and area, particle processing rate, and power consumption. All designs are implemented and tested on an Actel ProASIC 3E A3PE1500 FPGA using only the features available on the radiation-tolerant Actel RTAX 2000 S/SL. The designs achieve resolutions of 130 ps to 25 ns and particle rates of 1.63 to 40 MHz, use from 0.02% to 7.5% of the FPGA area, and consume from 396 to 448 mW. The TOF measurements of the Fast-Clocking Design show no thermal variation across the ranges of -25°C to 55°C. The other three designs vary linearly with temperature, but this variation can be calibrated using a temperature sensor. All four designs offer a flexible, inexpensive TOF measurement system that can be implemented across a broad range of FPGAs.

There are several operations in non-numeric processing which can be classified as file operations. These operations include such things as sorting, searching, and table lookup. They are characterized by their repetitious, homogeneous treatment of fields within records within files. Present computer organizations generally require several instructions imbedded in a loop to process each source-operand pair. This paper outlines a computer organization (called a streaming processor) which operates on long data streams with considerably less instruction processing overhead: fetching and decoding. Thus a greater percentage of the storage bandwidth is used for data and consequently the streaming processor is more efficient for such file operations.