Freescale Semiconductor,inc.

Nxp Usa, Inc.

Zhiling Sui

Zhijun Chen

Zhihong Cheng

Wangsheng Mei

Yan Xiao

SHixiang Nie

Chaoxuan Tian

Yanping Zhang

Liang Jia

Jiangtao Pan

A multi-core processor manages contention amongst its cores for access to a shared resource using a semaphore that maintains separate access-request queues for different cores and uses a selectable scheduling algorithm to grant pending requests, one at a time. The semaphore signals the core whose request is granted by sending it an interrupt signal using a dedicated core line that is not part of the system bus. The granted request is then de-queued, and the core accesses the shared resource in response to receiving the interrupt signal. The use of dedicated core lines for transmitting interrupt signals from the semaphore to the cores alleviates the need for repeated polling of the semaphore on the system bus. The use of the scheduling algorithm prevents a potential race condition between contending cores.

Semaphore for multi-core processor

A frequency shift keying (FSK) demodulation component having of a sampler that receives an FSK modulated signal, samples the received FSK modulated signal, and outputs the sampled signal. The FSK demodulation component further includes a low pass filter that filters the sampled signal, and a frequency shift detector that detects shifts in frequency of the low pass filtered sampled signal. The FSK demodulation component then outputs an indication of the detection of shifts in frequency of the low pass filtered sampled signal.

Wireless charger using frequency aliasing FSK demodulation

A method of demodulating an FSK modulated input signal whose frequency varies between first and second frequencies. The input signal is delayed by a plurality of cycles, providing a second signal. A succession of phase reference signals having respective incrementally greater phase delays relative to the input signal are provided. Samples of the phase reference signals are taken at intervals determined by the second signal. A transition between the first and second frequencies is detected when the relative values of the samples of the phase reference signals remain constant during a plurality of intervals after varying. A high speed clock is not required to perform the demodulation.

Demodulating frequency shift keying modulated input signal

A clock switching circuit includes first and second clock lines, first and second selection lines, and first through fourth Muller C-elements. The Muller C-elements are connected to the clock and selection lines and first and second logic gates. First and second delay cells are connected to the clock lines and the second and fourth Muller C-elements. A first AND gate is connected to the first clock line, the first Muller C-element, and the first delay cell. A second AND gate is connected to the second delay cell, the third Muller C-element, and the second clock line, and an OR gate is connected to the first and second AND gates.

Glitch-free clock switching circuit using Muller C-elements

A demodulator suitable for demodulating binary FSK signals having a small difference between carrier frequencies uses a counter-timer technique for timing a fixed number FSK cycles and comparing a count value with a threshold when a frequency change is expected. By grouping a number of FSK pulses (or cycles) together in one measurement, speed requirements on the system clock used for the counter/timer measurements can be relaxed and tolerance to noise is also improved. The demodulator is particularly suitable for wireless charging applications.

FSK demodulator

A pipelined analog-to-digital converter (ADC) that converts an analog input voltage signal Vinto a digital output value D. The ADC has a sequence of stages including a first calibrated stage having: (1) an ADC sub-module that receives Vand provides an ADC sub-module digital output value based on V, (2) a DAC sub-module that receives the ADC sub-module digital output value and outputs a corresponding analog voltage signal V, (3) a first difference module that generates an analog residual-voltage signal based on a difference between Vand V, and (4) an artificial-noise-insertion module that inserts an analog artificial-noise voltage signal into the residual voltage signal to generate an analog combined voltage signal. The analog combined voltage signal is used to calibrate the first calibrated stage. The artificial-noise-insertion module generates the polarity of the artificial-noise voltage signal based on the polarity of the corresponding residual voltage signal.

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Suzhou, China

Zhiling Sui