The capacitor code refers to a numerical system used to identify the value of a ceramic capacitor, typically using a three-digit code. The first two digits represent the significant figures, and the third digit is the multiplier. When working with Xilinx FPGAs, understanding these codes is crucial for selecting the right capacitors for power regulation and signal integrity within the FPGA design. Proper capacitor selection ensures stable operation and performance of the [Xilinx FPGA](https://www.dyethin.com/manufacturers/xilinx-inc) in various applications.