Apparatus and method for controlling a phase-locked loop circuit

摘要

A first and second phase-locked loop each having their frequency of operation under programmable control by changing the divider ratio. A single programming word contains the divider ratio for the first phase-locked loop and addressing bits which address a plurality of auxiliary registers for changing the divider ratio of the second phase-locked loop. In a cellular telephone, this allows the digital signal processor to change from receive to transmit mode or from one transmit mode or from one frequency to another utilizing a single command word.