Digital circuit system of linear frequency modulation continuous wave phase-locked loop and phase-locked loop

The invention discloses a digital circuit system of a linear frequency modulation continuous wave phase-locked loop and the phase-locked loop, belongs to the technical field of integrated circuits, and solves the problems that digital circuits in an existing phase-locked loop are various in type, long in design period and low in design efficiency. According to the technical scheme, a control signal in a corresponding mode is generated according to an input mode selection signal, a frequency sweeping maximum value, a frequency sweeping minimum value and a frequency sweeping step to control a control signal generation unit, an address code generation unit, a frequency dividing ratio searching unit, a differential integral modulator, a frequency dividing ratio decoding unit and a dual-mode frequency divider, a multi-functional frequency sweep mode with adjustable continuous frequency and fixed frequency output is realized, the requirements of different phase-locked loop systems are met, the number of types of di