Sequence detection is used in many algorithms and applications. Sequences are different depending on different demands. In the process of floating-point CORDIC coprocessor design,data are need to change from floating point format to fixed point format. This process is necessary to detect the number of consecutive zeros. We design the leading-zero-counting algorithm to achieve this function, and this conversion process is completed in a very fixed short time, to ensure the needs of the floating point CORDIC coprocessor.