A Low-Power Digitally Controlled Oscillator for All Digital Phase-Locked Loops

Table 4

Impact of each control bit on the DCO period.

Status	Function
“000”	Fine the control word for $T=T_{\text{ref}}$
“001”	Reset DCO in order to find the delay value $T_{\text{Delay}}$
“010”	Find a new control word for $T=T_{\text{ref}}-T_{\text{Delay}}$
“011”	Reset DCO in order for the phase alignment
“100”	Maintenance Mode