31 results about "Word clock" patented technology

The present invention provides a data transfer system including a data transmitter and a data receiver. The data transmitter converts a plurality of bits of transmission parallel data into serial data and generates a multi-level logic signal representing a plurality of bits of information in one symbol, the information being obtained by combining the serial data with a word clock as one-bit information. The word clock indicates a word delimiter in the serial data. The data receiver receives the transmitted multi-level logic signal, extracts the serial data and the word clock from the signal, and reproduces the parallel data based on the extracted word clock. In the data transfer system, a multi-bit digital signal can be transmitted as one signal including a word clock. Thus, components and mounting space to be allocated to transfer can be reduced.

A bi-directional serializer/deserializer is disclosed using a single bi-directional data line and a single bi-directional clock line. Gated buffers are controlled to operate either sending or receiving data, and a phase locked loop provides a clock to shift data out from a shift register. A reference clock is supplied to the PLL and the PLL generates a synchronous bit clock. The bit clock is sent over the clock line in parallel with the serial data bits, and the PLL bit clock is synchronized to the data bits. Two data boundary bits are inserted between the word data bits, the boundary data bits are arranged with a logic level transition between the two data boundary bits. Also, at the boundary of the words during the sending of the two boundary data bits, the synchronous bit clock is arranged to have no logic level transition. The receiving system will use the bit clock to serial load the received word and boundary data bits into a shift register. A word boundary is detected by sensing a data bit transition while there is no bit clock.

A computer audio interface unit (110) comprises a serial computer interface (e.g. USB) (204) providing a connector (112) for connection to an external, computer-based source (100) of digital audio data samples. A digital audio output connector (130) provides a digital audio output signal to external audio reproduction apparatus (106, 108). A word clock output connector (134) provides a word clock signal to external audio reproduction apparatus, in parallel with said digital audio output signal. An encoder (202/308) receives digital audio data via said USB interface and outputs said digital audio output signal. Clocking circuitry (202/300, 312) is responsive to a timing reference signal (200) independent of said external source (100), and generates said word clock signal for output to the external reproduction apparatus. Said clocking circuitry further generates a clock signal (302) for the USB interface (204) so as to synchronise the drawing of said audio data samples via said USB interface with the generated external word clock signal and the digital audio output signal. Interface and encoder functions may be housed separately from a master clock function.

An electronic device (11) according to the present invention includes a semiconductor integrated circuit (16) on which a pulse conversion circuit (17) for converting an acoustic signal received by a radio receiver (13) into a pulse signal is integrated. The pulse conversion circuit (17) includes a clock generator (110) which generates plural clocks and selects word clocks (210,211) according to the reception frequency of the radio receiver (13), an FSC (111) which performs sampling frequency conversion so as to make a sample sequence of an A/D converted acoustic signal have the same frequency as that of the word clock (210), a noise shaper (112) for performing noise shaping to the sample sequence outputted from the FSC (111) using the word clock (211), and a PWM modulator (113) for generating a pulse signal from the output of the noise shaper (112) using the word clock (211). Therefore, it is possible to avoid radio reception interference which may caused by the pulse signal when driving a speaker with the pulse signal.

A bi-directional serializer/deserializer is disclosed using a single bi-directional data line and a single bi-directional clock line. Gated buffers are controlled to operate either sending or receiving data, and a phase locked loop provides a clock to shift data out from a shift register. A reference clock is supplied to the PLL and the PLL generates a synchronous bit clock. The bit clock is sent over the clock line in parallel with the serial data bits, and the PLL bit clock is synchronized to the data bits. The receiving system will use the bit clock to serial load a receiving shift register. When a word is received a word clock is available to inform the receiving system. An embodiment of the system sends data to a receiving system using a clock generated at the sending system. Another embodiment receives data but uses a clock that is sent from the receiving system to the sending system, wherein the sending system uses the received clock to generate a clock to send the data and a synchronous clock that is sent back to the receiving system to load the data from the data line.

The invention provides a spread spectrum modulation method for a filterless digital D class audio power amplifier. A power amplifier main clock signal clk and an UPWM generator are used input a synchronous word clock signal clk_s1, another clock signal clk_s2 is synthesized according to a certain rule, and then a pseudo random number generator is constructed to generate a series of pseudo random number sequences. By judging the parities of the pseudo random number sequences, the clock signal clk_s1 and the clock signal clk_s2 are used to form a frequency variable clock signal clk_c through synthesis, and finally a PRF variable left-growth double-edge UPWM signal is processed and outputted through a threshold calculator, a counter and a comparator by using the amplitudes of the main clock signal clk, the clock signal clk_c and the UPWM generator input signal. At the same time, a corresponding filter-free pulse width modulator is designed based on the above spread spectrum modulation method. According to the method, the amplitude of a high-frequency component of a power amplifier output UPWM signal can be obviously reduced, thereby an EMI is reduced, the implementation is easy, and few hardware resources are needed.

A waveform data processing apparatus has a bus that transfers data signals representative of waveform data. A plurality of transmitting nodes transmit the data signals to the bus. A plurality of receiving nodes receive the data signals from the bus. A clock generator generates a word clock signal at each sampling period. A controller is responsive to the word clock signal for conducting a session of transferring the data signals within a sampling period, such that the transmitting nodes sequentially transmit the data signals in an order predetermined by the controller so as to avoid collision of the data signals within the sampling period, and each of the receiving nodes selectively admits a necessary one of the data signals outputted from the transmitting nodes and processes the admitted data signal within the sampling period.

A circuit for receiving multiple serial datastreams in parallel is disclosed. A bit clock is recovered from each data stream, there being one data bit for ach transition of the clock signal both positive and negative going. The phases of the bit clocks are compared and are adjusted by 180 degrees so that the positive going edges of all occur close to each other. The bits of each stream are assembled into words under the control of a word clock. In one embodiment a common word clock is derived form the set of bit clocks as a whole. In another embodiment each stream is provided with its own word clock which is aligned to positive edges of the respective bit clocks that are close to each other.

The invention provides a fractional frequency all-digital phase-locked loop and a control method thereof. The method comprises the following steps: S1, a fractional frequency controller generates a delay control word, a frequency division ratio control word, an integer frequency control word and a fractional frequency control word according to an external fractional frequency control word; s2, theclock generation and control circuit generates a clock signal ckr according to the reference clock and the frequency control word; s3, the digital time converter generates a low-frequency clock signal according to the ckr and the delay control word; s4, the feedback signal generation circuit outputs a feedback signal fb according to the frequency division ratio control word and a high-frequency clock signal ckv generated by the numerical control oscillator; s5, the phase discriminator generates phase error digital signals phe of ckr and fb; s6, the auxiliary frequency locking loop outputs a control signal ft1 according to the integer frequency control word, the fractional frequency control word and the low-frequency clock signal, and the numerical control oscillator updates ckv accordingto the sum of ft1 and phe.

The invention provides a multi-path audio collecting system comprising a TVL320AIC32 chip and a TVP5158 chip which are arranged in a cascade connection way, wherein a bit clock record pin of the TVP5158 is connected with a master clock pin of the TVl320AIC32; and a serial data output pin, a bit clock input pin in a cascade connection mode and a word clock pin of the TVl320AIC32 are respectively connected with a serial data input pin, a bit clock input pin in a cascade connection mode and a word clock input pin in a cascade connection mode of the TVP5158. The TVP5158 can process four-path video signals and four-path audio signals, therefore, one-path stereophony (two-path single-channel voice) signals, four-path voice signals and four-path video signals can be processed after the TVL320AIC32 and the TVP5158 are connected in a cascade connection way. The function of the TVP5158 is fully utilized, thereby not only saving the cost of hardware, but also reducing the size of products and enabling the products to develop in a smaller way.

A data transmission system comprising a transmitter and a receiver that use a single external word clock to generate all needed clocks locally using a clock generator and a phase locked loop. Data words are transmitted on a transmission line based on a single transition of the word clock. The transmitter and receiver may each be incorporated on a single chip.

A sampling frequency conversion device comprises an internal circuit for executing in synchronization with an internal clock a signal processing of input data fetched in accordance with an input word clock, and for outputting the input data having undergone the signal processing as output data, a clock generation circuit for generating from the internal clock an output word clock and a counter clock having a frequency which is equal to that of the output word clock multiplied by n (n: integer equal to two or more), a counter for counting the counter clock, and a register for holding a counter value of the counter in synchronization with the input word clock, and for outputting the held counter value to the internal circuit

Methods and Apparatuses are provided for automatically converting a word length of sample data being transmitted over a serial link. A serial interface transmits and/or receives one or more data words comprising digital signals, a bit clock synchronizes transmission of individual bits, and a word clock is used to group the bits into sample words. A desired word length is determined based on the relationship between the bit clock and the word clock during the transmission or reception of a data word. Based on the desired word length, the sample data is either truncated or padded, and an appropriate amount of dither is added to the sample words to reduce the distortion and quantization artifacts introduced by the word length conversion.

The invention discloses an analog-to-digital conversion system and audio equipment. The analog-to-digital conversion system comprises a clock control circuit which is used for providing clock signals according with each design ratio according to different preset oversampling rates, wherein the clock signal comprises a first digital clock signal, a second digital clock signal and an analog clock signal; an analog circuit which is used for outputting corresponding oversampling signals according to different analog clock signals; and a digital circuit which is used for performing first extraction on the oversampling signal according to the first digital clock signal to obtain a first extraction signal, and further performing second extraction on the first extraction signal according to the second digital clock signal to output a second extraction signal meeting the sampling rate requirement. Therefore, the oversampling rate of the system can be improved and higher performance can be obtained in an application requiring high performance, and the working frequency of the system can be reduced and power consumption can be saved by using a low oversampling rate in a low-power-consumption application.

The present invention relates to a digital clock generation apparatus. The digital clock generation apparatus is directed to providing a digital clock generation apparatus in which hardware is simple, duty cycles are easily controlled, and various duty cycles and various frequency clocks (n× clocks) are provided as compared to a 1× single-phase clock generation apparatus or a 1× multi-phase clock generation apparatus based on the conventional programmable delay element chain.

The invention discloses a clock skew elimination method of a 3D stacked memory, a clock skew elimination circuit of the 3D stacked memory and the 3D stacked memory. The clock skew elimination method comprises the following steps: generating a preset digital clock phase according to an original signal phase of a write data gating pin and original signal phases of all data pins, so as to enable thepreset digital clock phase to lag behind the original signal phase of the data gating pin and the original signal phase of each data pin; comparing the original signal phase of each data pin with a preset digital clock phase, and delaying the original signal phase of each data pin to ensure that the signal phase of each data pin is consistent with the preset digital clock phase. According to the embodiment, delay control is carried out on each data pin according to the preset digital clock phase, so that pin deflection is eliminated, and the data transmission reliability of the 3D stacked memory is improved.

When receiving the reproduced data from the optical disc and buffering same, the buffering from the correct position can be started on the basis of the synchronous signal and the address information included in the sub data which was received simultaneously.

There is provided a method for controlling the buffering of the main data which is reproduced from the optical disc, in which the main data and the sub data are received with taking word clocks which are partitioning timings having plural bits of the main data as a unit as references, a synchronous signal which is in synchronization with the main data is generated, and the buffering of the main data is started on the basis of the synchronous signal.

A method for phase alignment of active and standby clocks in a communication device, wherein at least one frequency-modulated direct digital frequency synthesizer (DDS) and at least one phase-modulated DDS are respectively arranged on the main clock board and the standby clock board, wherein the frequency-modulated DDS tracks an external clock The reference source synthesizes the frequency required by the output clock, and writes the frequency adjustment word that is the same as the frequency adjustment word of the frequency modulation DDS or has a fixed proportional relationship on the phase modulation DDS, and outputs the clock of the corresponding frequency; The relationship is detected, and the value of the phase register of the phase modulation DDS on the standby clock board is adjusted according to the detection result, and the output phase of the standby clock board is adjusted to align the phases of the main and standby output clocks. The invention improves the precision of the phase alignment, reduces the frequency synchronization requirements of the main and standby clock phase alignment, and improves the reliability of the clock system.

The invention discloses a bidirectional audio signal converter, and the converter comprises a shell, an analog-digital conversion part, a digital-analog conversion part and a clock part; the analog-digital conversion part, the digital-analog conversion part and the clock part are arranged in the shell, and the analog-digital conversion part comprises an analog input part, an analog-digital conversion part and a digital output part which are connected in sequence; the analog input part is used for inputting a level signal, the analog-to-digital conversion part is electrically connected with the analog input part and is used for converting an analog signal into a digital signal with independent word clock, bit clock and data, and the digital output part is electrically connected with the analog-to-digital conversion part and is used for synthesizing the digital signal into a digital audio signal meeting the AES-3 standard. The converter can be used as an A/D converter for converting a received audio analog signal into a digital signal, and can also be used as a D/A converter for converting a digital audio signal into an analog signal for connecting a monitoring loudspeaker and a cinema audio-visual disability system.