Abstract: A data transmission technique where high speed data is transmitted differentially in a forward channel by way of a serial link, and relatively low speed data is differentially modulated onto the forward channel signal for transmission in a reverse channel via the link. By utilizing differential modulation in both forward and reverse channels, the resulting signal has a common mode voltage that is substantially constant, resulting in low EM!. The spectral content of the signal associated with the high speed data may be substantially non-overlapping with the spectral content of the signal associated with the low speed data. This facilitates the recovery of the high speed data and low speed data with minimal interference. The differential signaling lends itself for communicating data via an inexpensive medium, such as twisted wire pair or parallel PCB traces. The data transmission technique applies to various communication network topologies: point-to-point, daisy-chain, and point-to-multiple points.

Abstract: A system for full duplex communication using a single-ended communications link is described. The system includes a first link interface configured to generate a signal for transmission via the single-ended communications link. The signal includes data encoded in a forward channel. The system also includes a second link interface configured to receive the signal from the first link interface via the single-ended communications link and modulate the signal to encode data in a reverse channel so that the signal includes the forward channel data and the reverse channel data simultaneously.

Abstract: An apparatus for generating a spread-spectrum signal based on an input signal whose frequency may vary substantially. The apparatus is particularly suited for controlling the frequency of the modulation in response to wide variations of the frequency of the input signal. This prevents the modulation frequency from deviating into an undesired frequency range which could cause adverse operational effects. The apparatus includes a detector adapted to generate a first signal related to the frequency of the input signal, a controller adapted to generate a second signal for controlling a frequency of a modulation signal based on the first signal, a modulation signal generator adapted to generate the modulation signal based on the second signal, and a spread-spectrum signal generator adapted to generate the spread-spectrum signal based on the modulation signal.

Abstract: System and method for transmitting video and audio data words via a serial data link. A transmitting device includes a first module for generating an audio data frame comprising an audio data word and a frame separation code; and a second module for generating high speed data frames each comprising at least a portion of a video data word and only a portion of the audio data frame, and for transmitting the high speed data frames via the serial data link. A receiving device includes a first module for forming the video data word from one or more high speed data frames, and a second module for forming the audio data frame from portions of high speed data frames. The second module may extract the audio data word from the audio data frame, and generate an audio clock based on a rate in which audio data words are received.

Abstract: A system for full duplex communication using a single-ended communications link is described. The system includes a first link interface configured to generate a signal for transmission via the single-ended communications link. The signal includes data encoded in a forward channel. The system also includes a second link interface configured to receive the signal from the first link interface via the single-ended communications link and modulate the signal to encode data in a reverse channel so that the signal includes the forward channel data and the reverse channel data simultaneously.

Abstract: An apparatus for transferring data in a non-spread domain to a spread domain. The apparatus comprises a first-in-first-out (FIFO) memory; a write pointer generator adapted to generate a write pointer for writing data into the FIFO memory in response to a non-spread clock signal; a spread-clock generator adapted to generate a spread clock signal based on the non-spread clock signal; a read pointer generator adapted to generate a read pointer for reading data from the FIFO memory in response to the spread clock signal; and a controller adapted to control the spread-clock generator in response to the read and write pointers indicating predetermined potential data overflow or underflow of the FIFO memory.

Abstract: A data transmission technique where high speed data is transmitted differentially in a forward channel by way of a serial link, and relatively low speed data is differentially modulated onto the forward channel signal for transmission in a reverse channel via the link. By utilizing differential modulation in both forward and reverse channels, the resulting signal has a common mode voltage that is substantially constant, resulting in low EM!. The spectral content of the signal associated with the high speed data may be substantially non-overlapping with the spectral content of the signal associated with the low speed data. This facilitates the recovery of the high speed data and low speed data with minimal interference. The differential signaling lends itself for communicating data via an inexpensive medium, such as twisted wire pair or parallel PCB traces. The data transmission technique applies to various communication network topologies: point-to-point, daisy-chain, and point-to-multiple points.

Abstract: A data transmission technique where high speed data is transmitted differentially in a forward channel by way of a serial link, and relatively low speed data is differentially modulated onto the forward channel signal for transmission in a reverse channel via the link. By utilizing differential modulation in both forward and reverse channels, the resulting signal has a common mode voltage that is substantially constant, resulting in low EMI. The spectral content of the signal associated with the high speed data may be substantially non-overlapping with the spectral content of the signal associated with the low speed data. This facilitates the recovery of the high speed data and low speed data with minimal interference. The differential signaling lends itself for communicating data via an inexpensive medium, such as twisted wire pair or parallel PCB traces. The data transmission technique applies to various communication network topologies: point-to-point, daisy-chain, and point-to-multiple points.

Abstract: An apparatus that includes a module for controlling the frequency of a voltage controlled oscillator (VCO) as part of a phase locked loop (PLL), or clock and data recovery (CDR) when an input reference signal to the PLL or serial data to the CDR has ceased from being received. In particular, the apparatus comprises a VCO adapted to generate a VCO clock signal, a first control module adapted to control the frequency of the VCO clock signal based on the input reference signal, and a second control module adapted to control the frequency of the VCO clock signal in response to an absence of the input reference signal. By controlling the frequency of the VCO clock signal during an absence of the input reference signal, the first control module is able to more easily re-acquire control the frequency of the VCO clock signal when the input reference signal is received again.

Abstract: An apparatus for generating a pulse having a pulse width substantially independent of process variation in resistive and capacitive values. The apparatus includes a PTAT current source to generate a first current to charge a capacitor to produce a first voltage; a ?VGS current source to generate a second current through a resistor to produce a second voltage V2; a comparator to generate the pulse in response to the first and second voltages; and a circuit to enable the charging and discharging of the capacitor. The use of the distinct current sources (e.g., PTAT and ?VGS) enables the pulse generator to be configured substantially process independent of resistive value. The use of a MOSFET capacitor for the capacitor enables the pulse generator to be made substantially process independent of capacitive value. An additional bandgap current source in parallel with the ?VGS current source reduces the pulse width dependency on temperature.

Abstract: An apparatus for generating a spread-spectrum signal based on an input signal whose frequency may vary substantially. The apparatus is particularly suited for controlling the frequency of the modulation in response to wide variations of the frequency of the input signal. This prevents the modulation frequency from deviating into an undesired frequency range which could cause adverse operational effects. The apparatus includes a detector adapted to generate a first signal related to the frequency of the input signal, a controller adapted to generate a second signal for controlling a frequency of a modulation signal based on the first signal, a modulation signal generator adapted to generate the modulation signal based on the second signal, and a spread-spectrum signal generator adapted to generate the spread-spectrum signal based on the modulation signal.

Abstract: System and method for transmitting video and audio data words via a serial data link. A transmitting device includes a first module for generating an audio data frame comprising an audio data word and a frame separation code; and a second module for generating high speed data frames each comprising at least a portion of a video data word and only a portion of the audio data frame, and for transmitting the high speed data frames via the serial data link. A receiving device includes a first module for forming the video data word from one or more high speed data frames, and a second module for forming the audio data frame from portions of high speed data frames. The second module may extract the audio data word from the audio data frame, and generate an audio clock based on a rate in which audio data words are received.

Abstract: A data transmission technique where high speed data is transmitted differentially in a forward channel by way of a serial link, and relatively low speed data is differentially modulated onto the forward channel signal for transmission in a reverse channel via the link. By utilizing differential modulation in both forward and reverse channels, the resulting signal has a common mode voltage that is substantially constant, resulting in low EMI. The spectral content of the signal associated with the high speed data may be substantially non-overlapping with the spectral content of the signal associated with the low speed data. This facilitates the recovery of the high speed data and low speed data with minimal interference. The differential signaling lends itself for communicating data via an inexpensive medium, such as twisted wire pair or parallel PCB traces. The data transmission technique applies to various communication network topologies: point-to-point, daisy-chain, and point-to-multiple points.

Abstract: An apparatus for generating a pulse having a pulse width substantially independent of process variation in resistive and capacitive values. The apparatus includes a PTAT current source to generate a first current to charge a capacitor to produce a first voltage; a ?VGS current source to generate a second current through a resistor to produce a second voltage V2; a comparator to generate the pulse in response to the first and second voltages; and a circuit to enable the charging and discharging of the capacitor. The use of the distinct current sources (e.g., PTAT and ?VGS) enables the pulse generator to be configured substantially process independent of resistive value. The use of a MOSFET capacitor for the capacitor enables the pulse generator to be made substantially process independent of capacitive value. An additional bandgap current source in parallel with the ?VGS current source reduces the pulse width dependency on temperature.

Abstract: An apparatus for generating a pulse having a pulse width substantially independent of process variation in resistive and capacitive values. The apparatus includes a PTAT current source to generate a first current to charge a capacitor to produce a first voltage; a ?VGS current source to generate a second current through a resistor to produce a second voltage V2; a comparator to generate the pulse in response to the first and second voltages; and a circuit to enable the charging and discharging of the capacitor. The use of the distinct current sources (e.g., PTAT and ?VGS) enables the pulse generator to be configured substantially process independent of resistive value. The use of a MOSFET capacitor for the capacitor enables the pulse generator to be made substantially process independent of capacitive value. An additional bandgap current source in parallel with the ?VGS current source reduces the pulse width dependency on temperature.

Abstract: An input circuit allows input buffers fabricated using submicron CMOS technologies to receive input signals having a voltage swing of 5V. The input circuit uses a cascode transistor to bias the drain of the input transistor so that the VGD of the input transistor does not reach or exceed the gate-oxide breakdown voltage. Outputs of the input buffers have a maximum voltage that is limited by their respective supply voltages.