Research And Implement Of Precise Time-interval Measurement Based On FPGA

With the rapid development of science and technology, the demand of high-precision time and frequency are increasingly higher. The traditional Disciplined Clock System (adaptive frequency calibration system) adopts analog or semi-digital system, which use high precision time-interval counter measure time part. But it exists shortcoming such as: high cost, large impact by environmental factors. Development of microelectronics technology, and promote the development of programmable logic technology. There has been a low price, suitable for engineering applications of field programmable gate array (FPGA). So reaching precise time-interval measure based on FPGA has the great practical significance.This paper analysis the commonly methods of time-interval. And the event delay interpolation method, the clock delay interpolation and the interpolation of three differential delay time interpolations of the simulation results show that the differential delay line based on the highest resolution measurements, a minimum consumption of hardware resources. On this basis, I design to realizing a 43ps delay difference of differential delay based on Cyclone II series of Alteras'EP2C70F672C8 chip. An integrated high-precision time interval measurement module be designed and embedded in FPGA. I determine the specific measurement for time interval: design by crude and fine measurement. The main modules are: System clock module, coarse measurement module, and fine measurement units, data processing and data transmission modules. Finally use the VerilogHDL software to simulate the entire program in the Quartus9.0 .Finally, I build a test platform, experimental platform to build on this specific test program. The results show that the FPGA-based time interval measurement accuracy of 200ps, with high accuracy, high integration, easy-to-transplant characteristics. It is a better design, has a good application prospects.