FPGA-based addition carry chain delay measurement method and system

Abstract

The invention provides an FPGA-based addition carry chain delay measurement method and system. The measurement method comprises steps: pulse test signals trigger the carry chain of a multi-bit adder,and according to the change condition of the current pulse test signals, the operation position value of the carry chain is acquired; with the clock cycle for generating the pulse test signals as an interval, the pulse test signals are translated sequentially, and after each time of pulse test signal translation, the operation position value can be triggered and acquired again until the operationposition values corresponding to all operation positions in the carry chain are acquired; and the relationship data between each operation position value of the carry chain and the corresponding position of each pulse test signal are acquired, and according to the relationship data, the delay time at each operation position of the carry chain is obtained. The delay time between different carry chains can be measured in real time, influences of temperature and voltage fluctuations can be avoided, and FPGA-based TDC module high-precision timing can be realized.

Description

technical field [0001] The invention relates to the technical field of digital measurement, in particular to an FPGA-based measurement method and system for adding and carrying chain delay. Background technique [0002] In the FPGA-based time-to-digital conversion TDC design architecture, the use of carry chain delay chains to obtain high-precision delay information has been widely used. However, this TDC based on the carry chain structure is limited by the uniformity of the carry chain. The ambient temperature and different FPGAs will change the delay of the carry chain, which is the main limiting factor to improve the performance of TDC. Therefore, it is necessary to measure the delay time of the carry chain in real time. [0003] At present, the carry chain measurement methods are mainly divided into analog and digital. Among them, the analog method is mainly realized by the feedback circuit, which is often used in integrated chips, while the carry chain measurement in th...

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Problems solved by technology

In actual situations, the measured number of carry chains is not a fixed value, and even needs to be expressed in decimals, so the average measurement method also needs to repeat the measurement many times, so as to provide higher-precision calibration. This method can be used during system operation. In real-time measurement, but it cannot reflect the difference in the delay time of each carry chain, and the accuracy is lacking

[0005] The BIN-by-BIN method needs to measure the delay time of each carry chain, which is usually measured by the code density method. The method is as follows: a square wave signal that is not related to the sampling clock is generated outside the system as the Hit signal. Each rising edge of , trig...

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