CPLD is the complex programmable logic device. The logic function of CPLD can be changed by different program. The applications of CPLD have not only simplified the circuit’s design and reduced its costs, but also enhanced the reliability and secrecy of the system. Here we introduce an example of the CPLD’s implementation in the CSR control system.The power supply control module structure diagram is shown in Fig.1. The applications of CPLDs have not only simplified the circuit’s design and reduced its costs, but also enhanced the reliability and secrecy of the system. Here we introduce an example of the CPLD’s implementation in the CSR control system. The power supply control module structure diagram is shown in FIG.