· The frequency synthesizer generates a range of frequencies from a single reference frequency, which usually comes from a crystal oscillator. Frequency synthesizers are one of the most critical building blocks in modern electronic devices, such as mobile telephones, laptops, televisions, radiotelephones, satellite communications, GPS systems, etc. One of the popular types of frequency synthesizers is a phase-locked loop (PLL). In Processing-in-Memory (PIM), PLL will be designed and used to synchronize a clock inside the PIM.