Embodiments of the present invention relate to an architecture that uses hierarchical statistically multiplexed counters to extend counter life by orders of magnitude. Each level includes statistically multiplexed counters. The statistically multiplexed counters includes P base counters and S subcounters, wherein the S subcounters are dynamically concatenated with the P base counters. When a row overflow in a level occurs, counters in a next level above are used to extend counter life. The hierarchical statistically multiplexed counters can be used with an overflow FIFO to further extend counter life.

Embodiments of the present invention disclose a frequency divider and a radio communications device. The frequency divider includes a shift register unit and an output frequency synthesizing unit; the shift register unit includes multiple cyclically cascaded basic units; a basic unit at each level includes 2.sup.N D flip-flops connected in series and a multiplexer, outputs of the 2.sup.N D flip-flops connected in series are separately connected to the multiplexer; an output of the multiplexer is connected to an input of a next-level basic unit; the output frequency synthesizing unit superposes an output signal of the first D flip-flop of the basic unit at each level to generate a frequency division output signal.

A frequency divider may include the following elements: a first inverter, a second inverter, and a third inverter, which are connected in a ring structure, wherein the second inverter is connected to an output terminal of the frequency divider; a fourth inverter connected to a first input terminal of the frequency divider and to a power supply terminal of the first inverter; a fifth inverter connected to a second input terminal of the frequency divider and to a power supply terminal of the third inverter; a first transistor connected to the second input terminal of the frequency divider and to a ground terminal of the first inverter; and a second transistor connected to the first input terminal of the frequency divider and to a ground terminal of the third inverter. The second inverter, the fourth inverter, and the fifth inverter may receive a power supply voltage.

A frequency divider may include the following elements: a first inverter, a second inverter, and a third inverter, which are connected in a ring structure, wherein the second inverter is connected to an output terminal of the frequency divider; a fourth inverter connected to a first input terminal of the frequency divider and to a power supply terminal of the first inverter; a fifth inverter connected to a second input terminal of the frequency divider and to a power supply terminal of the third inverter; a first transistor connected to the second input terminal of the frequency divider and to a ground terminal of the first inverter; and a second transistor connected to the first input terminal of the frequency divider and to a ground terminal of the third inverter. The second inverter, the fourth inverter, and the fifth inverter may receive a power supply voltage.

Systems and methods for dividing input clock signals by programmable divide ratios can produce output clock signals with the delay from the input clock signal to the output clock signal independent of the value of the divide ratio and with the duty cycle of the output clock signal being 50% independent of the value of the divide ratio. An example programmable clock divider includes a modulo N counter that produces a count signal that counts modulo the divide ratio and a half-rate clock signal generator that produces a common half-rate clock signal, an even half-rate clock signal, and an odd half-rate clock signal that toggle at one-half the rate of the output clock signal. The common half-rate clock signal, the even half-rate clock signal, and the odd half-rate clock signal are combined to produce the output clock signal.

A frequency divider includes a multiplexer having a first input terminal coupled to receive a first value M and a second input terminal for receiving a second value that is M+LSB, the multiplexer is configured to alternately output the first value M and the second value. The frequency divider includes a multi-modulus divider coupled to the multiplexer for receiving the output of the multiplexer, the multi-modulus divider operable to alternately generate an output pulse at M input clock cycles and at M+LSB clock cycles. A divide-by-two counter having an input coupled to the output of the multi-modulus divider, is operable to divide the output of the multi-modulus divider to generate a divided clock signal having a frequency of N, where N is equal to 2M+LSB. Duty cycle correction logic is coupled to the output of the divide-by-two counter and is configured to correct the duty cycle of the divided clock signal to a fifty percent duty cycle when N is odd.

The present disclosure provides a frequency generator, and belongs to the technical field of communications. The frequency generator provided by the present disclosure includes: N stages of mixing modules and N stages of comb spectrum generation modules. Each of the comb spectrum generation modules is configured to provide a mixing module in a same stage as the comb spectrum generation modules with one stage of fundamental signal group generated according to a second reference signal; and different stages of fundamental signal groups are generated based on different second reference signals. A 1.sup.st-stage mixing module generates a 1.sup.st-stage mixed signal according to a 1.sup.st-stage fundamental signal group and a first reference signal, and the 1.sup.st-stage fundamental signal group includes a plurality of harmonic signals with a first frequency as a fundamental frequency.

The present disclosure provides a frequency generator, and belongs to the technical field of communications. The frequency generator provided by the present disclosure includes: N stages of mixing modules and N stages of comb spectrum generation modules. Each of the comb spectrum generation modules is configured to provide a mixing module in a same stage as the comb spectrum generation modules with one stage of fundamental signal group generated according to a second reference signal; and different stages of fundamental signal groups are generated based on different second reference signals. A 1.sup.st-stage mixing module generates a 1.sup.st-stage mixed signal according to a 1.sup.st-stage fundamental signal group and a first reference signal, and the 1.sup.st-stage fundamental signal group includes a plurality of harmonic signals with a first frequency as a fundamental frequency.

An example apparatus includes: first through eighth gated inverters each having inputs and outputs; a first and second inverter each having an input and an output, the output of the first inverter coupled to the input of the second gated inverter, the output of the second inverter coupled to the input of the third gated inverter; the fifth gated inverter coupled to the input of the first gated inverter and the input of the first inverter; the sixth gated inverter coupled to the input of the second inverter and the input of the fourth gated inverter; the seventh gated inverter coupled to the output of the first gated inverter and the output of the third gated inverter; the eighth gated inverter coupled to the output of the second gated inverter and the output of the fourth gated inverter; and a bus-holder circuit between the seventh and eighth gated inverter inputs.

An example apparatus includes: first through eighth gated inverters each having inputs and outputs; a first and second inverter each having an input and an output, the output of the first inverter coupled to the input of the second gated inverter, the output of the second inverter coupled to the input of the third gated inverter; the fifth gated inverter coupled to the input of the first gated inverter and the input of the first inverter; the sixth gated inverter coupled to the input of the second inverter and the input of the fourth gated inverter; the seventh gated inverter coupled to the output of the first gated inverter and the output of the third gated inverter; the eighth gated inverter coupled to the output of the second gated inverter and the output of the fourth gated inverter; and a bus-holder circuit between the seventh and eighth gated inverter inputs.