A system and method for operating a data processing system to modify a time domain input signal to a signal generator to correct for distortions introduced by the signal generator are disclosed. The method includes receiving a target signal specifying a signal to be generated by the signal generator and initializing an input signal with the target signal, the method includes a) inputting the input signal to the signal generator to arrive at a signal generator output signal; b) measuring a frequency spectrum of the signal generator output signal with a test instrument; c) updating the input signal based on a comparison of said measured frequency spectrum and a frequency spectrum of target input signal; and d) repeating steps a)-c) until an exit condition is satisfied.

A system and method for operating a data processing system to modify a time domain input signal to a signal generator to correct for distortions introduced by the signal generator are disclosed. The method includes receiving a target signal specifying a signal to be generated by the signal generator and initializing an input signal with the target signal, the method includes a) inputting the input signal to the signal generator to arrive at a signal generator output signal; b) measuring a frequency spectrum of the signal generator output signal with a test instrument; c) updating the input signal based on a comparison of said measured frequency spectrum and a frequency spectrum of target input signal; and d) repeating steps a)-c) until an exit condition is satisfied.

A method and apparatus for controlling a frequency range of a self-resonant frequency (SRF) of a high speed divider implemented in current mode logic (CML) D triggers by controlling a field effect transistor (FET) load resistor bias voltage to FETs operating in linear regions in load resistors in the CML D triggers. Tail currents of the CML D triggers are controlled to track inversely to a resistor value.

A method and apparatus for controlling a frequency range of a self-resonant frequency (SRF) of a high speed divider implemented in current mode logic (CML) D triggers by controlling a field effect transistor (FET) load resistor bias voltage to FETs operating in linear regions in load resistors in the CML D triggers. Tail currents of the CML D triggers are controlled to track inversely to a resistor value.

An apparatus includes a processor, a Phase-Locked Loop Waveform Generator (PLLWG), a Voltage Controlled Oscillator (VCO), a demodulator, signal conditioning circuitry, and an Analog-to-Digital Converter (ADC). The processor generates control command signals, receives a digital data input signal, and performs spectrum analysis on the digital data input signal. The PLLWG is coupled to the processor, receives the control command signals, and generates a charge pump output signal based on the control command signals. The VCO is coupled to the PLLWG, receives a tuning signal based on the charge pump output signal, and outputs a VCO output signal based on the tuning signal. The demodulator receives an incoming modulated signal and the VCO output signal, and outputs an analog output signal based on the incoming modulated signal and the VCO output signal. The ADC converts the analog output signal into the digital data input signal.

An apparatus includes a processor, a Phase-Locked Loop Waveform Generator (PLLWG), a Voltage Controlled Oscillator (VCO), a demodulator, signal conditioning circuitry, and an Analog-to-Digital Converter (ADC). The processor generates control command signals, receives a digital data input signal, and performs spectrum analysis on the digital data input signal. The PLLWG is coupled to the processor, receives the control command signals, and generates a charge pump output signal based on the control command signals. The VCO is coupled to the PLLWG, receives a tuning signal based on the charge pump output signal, and outputs a VCO output signal based on the tuning signal. The demodulator receives an incoming modulated signal and the VCO output signal, and outputs an analog output signal based on the incoming modulated signal and the VCO output signal. The ADC converts the analog output signal into the digital data input signal.

According to one embodiment, in a semiconductor integrated circuit, a determination circuit is configured to generate first transition information, second transition information and phase determination information, with respect to a signal level of a modulation signal. The first transition information indicates a state of a first transition edge of transition between a first signal level and a second signal level. The second transition information indicates a state of a second transition edge of transition between a third signal level and a fourth signal level. The phase determination information indicates a result of a phase determination of a clock signal. An estimation circuit is configured to estimate a deviation between a timing of the first transition edge and a timing of the second transition edge according to the first transition information, the second transition information, and the phase determination information.

According to one embodiment, in a semiconductor integrated circuit, a determination circuit is configured to generate first transition information, second transition information and phase determination information, with respect to a signal level of a modulation signal. The first transition information indicates a state of a first transition edge of transition between a first signal level and a second signal level. The second transition information indicates a state of a second transition edge of transition between a third signal level and a fourth signal level. The phase determination information indicates a result of a phase determination of a clock signal. An estimation circuit is configured to estimate a deviation between a timing of the first transition edge and a timing of the second transition edge according to the first transition information, the second transition information, and the phase determination information.

A frequency measurement circuit includes a counter circuit to receive a first digitally-controlled oscillator (DCO) clock signal corresponding to a first DCO input codeword and a measurement signal. The counter circuit is responsive to the measurement signal to generate a count representing a measured frequency of the first DCO clock signal. A control circuit is configured to selectively adjust a parameter of the measurement signal for generating a second count of a second DCO clock signal corresponding to a second DCO codeword. The control circuit selectively adjusts the parameter based on a received control signal.

A frequency measurement circuit includes a counter circuit to receive a first digitally-controlled oscillator (DCO) clock signal corresponding to a first DCO input codeword and a measurement signal. The counter circuit is responsive to the measurement signal to generate a count representing a measured frequency of the first DCO clock signal. A control circuit is configured to selectively adjust a parameter of the measurement signal for generating a second count of a second DCO clock signal corresponding to a second DCO codeword. The control circuit selectively adjusts the parameter based on a received control signal.