一种设计数字锁相环的思路，包含异或鉴相器、k模可逆计数器、脉冲加减计数器、N分频器等，实现相位的锁定。(A design of digital phase locked loop (PLL) consists of a phase discriminator, a K mode reversible counter, a pulse addition and subtraction counter, a N frequency divider and so on, to lock the phase.)