Accumulator controlled prescaler in a phased locked loop

An integrated circuit chip having a phase locked loop circuit, comprising:

• a prescaler circuit configured to divide the frequency of an output signal of the phase locked loop circuit by a prescaler factor, said prescaler circuit being operable in at least two modes, each mode having assigned a different prescaler factor;
• and
• an accumulator circuit connected to said prescaler circuit configured to provide a mode switching signal to said prescaler circuit to switch between said at least two modes having assigned different prescaler factors, said accumulator circuit storing an accumulator value,
• wherein said accumulator circuit is adapted to repetitively update said accumulator value using a modulus function, to generate said mode switching signal to switch between said at least two modes having assigned different prescaler factors.

A transceiver in a WLAN (Wireless Local Area Network) communication system, the transceiver having a phase locked loop device comprising:

• a prescaler configured to divide the frequency of an output signal of the phase locked loop device by a prescaler factor, said prescaler being operable in at least two modes, each mode having assigned a different prescaler factor;
• and
• an accumulator connected to said prescaler configured to provide a mode switching signal to said prescaler to switch between said at least two modes having assigned different prescaler factors, said accumulator storing an accumulator value,
• wherein said accumulator is adapted to repetitively update said accumulator value using a modulus function, to generate said mode switching signal to switch between said at least two modes having assigned different prescaler factors.

A method of operating a phase locked loop device, the method comprising:

• dividing the frequency of an output signal of the phase locked loop device in a prescaler of said phase locked loop device by a prescaler factor, said prescaler being operable in at least two modes, each mode having assigned a different prescaler factor;
• and
• generating a mode switching signal for changing the mode of said prescaler to another mode of said at least two modes having assigned different prescaler factors,
• wherein generating the mode switching signal comprises:
• storing an accumulator value;
• and
• processing a modulus function for updating said accumulator value.