Phase control circuit and phase control method

The phase control circuit comprising:

• a phase comparing circuit which compares respective phases of a synchronizing signal and an internal signal, and which outputs a phase control signal indicative of a comparison result;
• a phase changing circuit which changes the phase of said internal signal according to said phase control signal, and which outputs the internal signal having the changed phase to a radio unit for synchronizing the radio unit;
• and
• a mask circuit which is responsive to an operational mode of the radio unit, and which selectively supplies said phase control signal to said phase changing circuit according to a voltage level of a guard timing signal received from the radio unit, wherein the guard timing signal indicates a guard timing term during a transmitting mode or a receiving mode of the radio unit.

A phase control circuit comprising:

• a phase comparing circuit which compares respective phases of a synchronizing signal and an internal signal, and which outputs a phase control signal indicative of a comparison result, and which further outputs a lock detection signal when a phase difference between the respective phases of the synchronizing signal and the internal signal is smaller than a predetermined value;
• a phase changing circuit which changes the phase of said internal signal according to said phase control signal, and which outputs the internal signal having the changed phase to a radio unit for synchronizing the radio unit;
• a control circuit which is responsive to an operational mode of the radio unit, and which outputs an enable signal when said lock detection signal and an inverted guard timing signal received from the radio unit have a first voltage level, wherein the guard timing signal indicates a guard timing term during a transmitting mode or a receiving mode of the radio unit;
• and
• a mask circuit which selectively supplies said phase control signal to said phase changing circuit according to a voltage level of said enable signal.

A phase control circuit comprising:

• a phase comparing circuit which compares respective phases of a synchronizing signal and an internal signal, and which outputs a phase control signal indicative of a comparison result, and which further outputs a first lock detection signal when a phase difference between the respective phases of the synchronizing signal and the internal signal is smaller than a predetermined value, and a second lock detection signal when said phase difference is larger than a second predetermined value which is smaller than said first predetermined value;
• a phase changing circuit which changes the phase of said internal signal according to said phase control signal, and which outputs the internal signal having the changed phase to a radio unit for synchronizing the radio unit;
• a control circuit which is responsive to an operational mode of the radio unit, and which outputs an enable signal when said first and second lock detection signals and an inverted guard timing signal received from the radio unit are input, wherein the guard timing signal indicates a guard timing term during a transmitting mode or a receiving mode;
• and
• a mask circuit which selectively supplies said phase control signal to said phase changing circuit when said enable signal is input.