高级检索

基于ZYNQ的高精度时间数字转换器的设计与实现

The Design and Implementation of ZYNQ-based High-precision Time-to-Digital Converter

  • 摘要: 高精度时间测量技术广泛应用于高能物理实验和核物理实验中,为满足兰州重离子加速器(Heavy Ion Research Facility in Lanzhou, HIRFL)放射性次级束分离线(Radioactive Ion Beam Line in Lanzhou, RIBLL)中飞行时间探测器(Time of Flight, TOF)对于时间测量高精度、宽动态范围的需要,基于Xilinx ZYNQ 7000全可编程28 nm片上系统,采用“粗计数”和“细计数”相结合的方法,实现了一种通过FPGA (Field Programmable Gate Array)内部逻辑延迟单元Carry4级联构建抽头延迟链的双通道时间数字转换器(Time to Digital Converter, TDC)。设计过程中,针对FPGA内部资源分布引起的“冒泡”问题,采用基于Ones Counter的算法进行优化处理;基于数据高速传输的需求,TDC的时间戳数据通过直接内存访问控制器(AXI DMA)从PL (Programmable Logic)传输到PS (Processing System)端DDR;最终PS端通过TCP/IP协议将数据发送至上位机进行标定和校准工作。经测试,该TDC设计方案500 MHz系统工作频率下最大测量范围为33.5 ms、时间分辨率低于15 ps、微分非线性DNL (Differential Nonlinearity)的范围为−0.01, 0.03 LSB,积分非线性INL的范围为−0.01, 0.06 LSB,实现了宽动态范围,线性度良好的高精度时间数字转换器。

     

    Abstract: High-precision time measurement technology is widely employed in high-energy physics experiments and nuclear physics experiments. To meet the demanding requirements of high precision and wide dynamic range for time measurement in the Time-of-Flight (TOF) detectors of the Radioactive Ion Beam Line in Lanzhou (RIBLL) at the Heavy Ion Research Facility in Lanzhou (HIRFL), a dual-channel Time-to-Digital Converter (TDC) has been implemented based on the Xilinx ZYNQ 7000 fully programmable 28nm System-on-Chip (SoC). This design adopts a combined method of "coarse counting" and "fine counting," utilizing cascaded Carry4 delay elements within the FPGA to construct a tapped delay line. During the design process, to address the "bubble" issue caused by uneven distribution of FPGA internal resources, an optimization algorithm based on Ones-Counter was implemented. To fulfill the requirements for high-speed data transmission, timestamp data from the TDC is transferred from the Programmable Logic (PL) section to the Processing System (PS) DDR memory via a Direct Memory Access (AXI DMA) controller. Ultimately, the PS section transmits the data to a host computer through TCP/IP protocol for calibration and alignment procedures. Testing results demonstrate that this TDC design achieves a maximum measurement range of 33.5 ms at a system clock frequency of 500 MHz, with a time resolution better than 15 ps. The differential nonlinearity (DNL) ranges from −0.01, 0.03 LSB, while the integral nonlinearity (INL) ranges from −0.01, 0.05 LSB. This design successfully realizes a high-precision time-to-digital converter with wide dynamic range and excellent linearity performance.

     

/

返回文章
返回