Abstract: A ROM or other memory may include two or more partitions and a precharge circuit. Each of the partitions may be coupled to separate sets of output conductors, to which the precharge circuit may be coupled. The precharge circuit may precharge the conductors of the partition to be read, while not precharging the other conductors. In one embodiment, the precharge may be to a voltage representing a binary value. In one implementation, the non-precharged conductors may be held to a predetermined voltage different from the voltage to which the precharged conductors are precharged. The predetermined voltage may represent the opposite binary value to the binary value represented by the precharge voltage. The ROM may also include an output circuit which may, in certain embodiments, comprise a logic circuit which logically combines the signals on respective conductors from each partition to provide output signals from the ROM.

Abstract: Improved carrier recovery, symbol timing, and carrier phase tracking systems and methods suitable for use in connection with a dual-mode QAM/VSB receiver system are disclosed. Carrier and phase recovery systems operate on complex signals representing symbols having the same time stamp for each phase error term. in-phase signals are sampled twice a symbol at the in-phase symbol sampling time and at the quadrature-phase symbol sampling time. The signals are de-multiplexed to generate I and XI data streams, where I represents the in-phase sampling time signals and XI represents mid-symbol point sample times. A similar procedure is carrier out on quadrature-phase signals. When the in-phase signal is de-multiplexed to generate a symbol I, the quadrature-phase signal is de-multiplexed to generate its mid-symbol point XQ. Both I and Q are decoded in a decision device to define a symbol error term, which is combined with the opposite mid-symbol signal to define a phase error term PI and PQ for each rail.

Abstract: A circuit for applying power to mixed mode integrated circuits in a predefined sequence. The circuit includes a first circuit powered by a first voltage and a second circuit powered by a second voltage that is less than the first voltage and having the second voltage coupled to the first circuit. The circuit for applying power to mixed mode integrated circuits includes a modified I/O cell of the second circuit. The modified I/O cell has a driver transistor including a back gate terminal, a gate terminal that is driven by the second circuit, a drain terminal that is coupled to a first circuit signal, and a source terminal that is coupled to the second voltage. The circuit for applying power to mixed mode integrated circuits further includes a controller circuit coupled to the first voltage and the second voltage supplied as controller circuit inputs. The controller circuit has a plurality of controller circuit outputs.

Abstract: Methods and apparatus for improving the current matching within current mirror circuits in applications such as low voltage integrated circuits. Embodiments of the present invention attempt to maintain the proper current ratio between reference and output supplies by adjusting the reference output of the current mirror. An existing reference voltage on the output side of the mirror can be used or a reference voltage can be created to be used for the voltage regulation of the reference side of the current mirror.

Abstract: A linearized oscillation synthesizer includes a phase and frequency detection module, charge pump circuit, low pass filter, voltage control oscillator, and a feedback module. The phase and frequency detection module is operably coupled to produce a charge-up signal, a charge-down signal, and an off signal based on phase and/or frequency differences between a reference oscillation and a feedback oscillation. The reference oscillation is generated by a clock source such as a crystal oscillator while the divider module generates the feedback oscillation by dividing the output oscillation by a divider value. The charge pump circuit produces a positive current in response to the charge-up signal, a negative current in response to the charge-down signal and also produces a non-zero offset current. The non-zero offset current shifts the steady state operating condition, and other operating conditions, of the charge pump into a linear region of charge pump performance curve.

Abstract: Clock signals and digital data signals at a variable frequency are introduced to the input of a FIFO and are passed from the FIFO at a second (or intermediate) frequency controlled by a numerically controlled oscillator. To regulate the frequency of the signals from the numerically controlled oscillator, the phases of the clock signals at the variable frequency are compared in a phase detector with the phases of the signals from the numerically controlled oscillator to generate an error signal. The error signals and the signals at a fixed sampling frequency higher than the intermediate frequency regulate the frequency of the signals from the numerically controlled oscillator and thus the frequency of the digital data signals from the FIFO. The digital data signals from the FIFO are converted to a pair of signals at the second frequency.

Abstract: Methods and apparatus are provided for an entity such as a CPU to efficiently call a cryptography accelerator to perform cryptographic operations. A function call causes the cryptography accelerator to execute multiple cryptographic operations in a manner tailored for specific processing steps, such as steps during a handshake phase of a secured session. The techniques provide efficient use of hardware processing resources, data interfaces, and memory interfaces.

Abstract: A node comprises one or more resources and a register programmable with an indication during use. The one or more resources are addressed with addresses within a local region of an address space. The indication identifies a second region of the address space that is aliased to the local region, and other nodes address the one or more resources using addresses in the second region.

Abstract: Methods and apparatus are provided for performing authentication and decryption operations. A record including multiple encrypted blocks is received. An encrypted block in the record is extracted and decrypted first in order to obtain context information for performing authentication operations. Each remaining block is then decrypted and authenticated by using the available context information. Authentication operations can be performed without having to wait for the decryption of all of the blocks in the record.

Abstract: An IQ receiver includes an estimator/compensator module to determine and correct IQ mismatch errors between the I and Q channels of the IQ receiver. The estimator module determines a phase compensation factor C1 and an amplitude compensation factor C2 based on a calibration signal that is injected into the analog front-end of the IQ receiver. A compensator module applies the phase correction factor C1 and the amplitude correction factor C2 to the baseband output of the Q channel in order to reduce any phase or amplitude errors between the I and Q channels. The estimator module and the compensator module can be efficiently implemented in a digital state machine, or processor, including a digital signal processor.

Abstract: A reference ladder is configured to have improved feedback stability. The reference ladder includes a resistor ladder having a plurality of taps that produce a plurality of reference voltages. The resistor ladder is driven by a first current source at a first tap of the plurality of taps and by a second current source at a second tap of the plurality of taps. A first feedback network senses a voltage at the first tap and controls the first current source based on the first sensed voltage. A second feedback network senses a voltage at the second tap and controls the second current source based on the second sensed voltage. The first and second taps each operate as both a force tap and a sense tap of the resistor ladder. Differential input stages that are connected to the plurality of taps are at least partially isolated from the feedback networks by converging the force and sense taps, thereby improving the stability of the feedback networks.

Abstract: A linearized oscillation synthesizer includes a phase and frequency detection module, charge pump circuit, low pass filter, voltage control oscillator, and a feedback module. The phase and frequency detection module is operably coupled to produce a charge-up signal, a charge-down signal, and an off signal based on phase and/or frequency differences between a reference oscillation and a feedback oscillation. The reference oscillation is generated by a clock source such as a crystal oscillator while the divider module generates the feedback oscillation by dividing the output oscillation by a divider value. The charge pump circuit produces a positive current in response to the charge-up signal, a negative current in response to the charge-down signal and also produces a non-zero offset current. The non-zero offset current shifts the steady state operating condition, and other operating conditions, of the charge pump into a linear region of charge pump performance curve.

Abstract: An analog to digital converter includes a first amplifier array connected to taps from a reference ladder, a second amplifier array, wherein each amplifier in the first amplifier array is connected to only two amplifiers of the second amplifier array, a third amplifier array, wherein each amplifier in the second amplifier array is connected to only two amplifiers of the third amplifier array, and an encoder connected to outputs of the third amplifier array that converts the outputs to an N-bit digital signal.

Abstract: A communication network having at least one access point supports wireless communication among a plurality of wireless roaming devices via a first and a second wireless channel. The access point comprises a first and a second transceiver. The first and second transceivers operate on the first and second wireless channels, respectively. Each of the plurality of wireless roaming devices are capable of communicating on the first and second wireless channel. In one embodiment, the first wireless channel is used to exchange data, while the second channel is used to manage such exchanges as well as access to the first channel. In an alternate embodiment, both channels are used to support communication flow, however the first channel supports a protocol that is more deterministic than that of the second channel. Allocation of ones of the plurality of wireless roaming devices from one channel to the next may occur per direction from the access point.

Abstract: A node comprises a first agent, a second agent, and a third agent, all coupled to an interconnect. The first agent is configured to initiate a transaction on the interconnect to transfer a coherency block to the second agent. The third agent is configured to transmit the coherency block on the interconnect during a data portion of the transaction instead of the first agent responsive to a state of the coherency block in the third agent. In some embodiments, the first agent may be designated to store the node state of a remote cache block, and the second agent may be responsible for internode coherency within the node.

Abstract: A memory access system is described which generates two memory addresses from a single memory access instruction which identifies a register holding at least two packed objects. In the preferred embodiment, the contents of a base register is combined respectively with each of two or more packed objects in an offset register.

Abstract: An Analog-to-Digital-Converter (ADC) converts an analog signal to digital data. The ADC includes a modulator, a decimation filter, and a time dither clock reduction circuit. The modulator receives the analog signal and a feedback signal and, based there upon, produces a modulated signal at a modulator clock rate. The decimation filter couples to the modulator, receives the modulated signal, and decimates and filters the modulated signal to produce the digital data. The time dither clock reduction circuit receives the modulated signal and provides the feedback signal to the modulator. The time dither clock reduction circuit applies both clock reduction and time dithering to the modulated signal to produce the feedback signal. At each modulator clock cycle, the time dithering clock reduction circuit considers modulated signals for a dithering factor, N, previous modulator clock cycles and a modulated signal for a current modulator clock cycle.

Abstract: A video and graphics system includes a video decoding system for processing compressed video data. The compressed video data includes MPEG-2 video data containing SDTV video data or HDTV video data. The video decoding system includes a video decoder for processing the compressed video data to generate displayable video, and a memory controller for transferring the compressed video data to and from an external memory. The video decoder requests to the memory controller to transfer the compressed video data using one of predetermined addressing patterns. The predetermined addressing patterns allow for more efficient transferring of the compressed video data to and from the external memory when compared to sequentially transferring a fixed number of data bytes starting at a fixed address. The use of the predetermined addressing patterns results in reading the compressed video data from the external memory in a predetermined order in a less number of clock cycles.

Abstract: A method for refreshing data in a circuit element included in a dynamic register. A static loop is coupled to the circuit element as a feedback path from the output terminal to the input terminal of the circuit element. A control signal is provided to the static loop. The static loop is activated via the control signal to refresh the data in the circuit element.

Abstract: A graphics integrated circuit chip is used in a set-top box for controlling a television display. The graphics chip processes analog video input, digital video input, graphics input and audio input simultaneously. A video scaling system preferably conserves memory by downscaling video prior to capturing the video in memory and upscaling video after the video is called out of memory.