数字环路滤波器是由变模可逆计数器构成的。 该计数器设计为一个17 位可编程(可变模数) 可逆 计数器,计数范围是,由外部置数DCBA 控制-Digital loop filter is composed of variable-mode reversible counter. The counter is designed to a 17-bit programmable (variable modulus) reversible counter, counting range is s