Abstract:
A microprocessor configured to detect subroutine call instructions having a target address indicative of a DSP function is provided. The detection of such instructions may be performed, for example, in an instruction decode unit within the microprocessor. Subroutine call instructions detected in this manner are routed to a digital signal processor coupled near the microprocessor or possibly integrated into the microprocessor. The microprocessor may be configured to store an indication that the DSP is enabled. If the DSP is not enabled, then the microprocessor executes the original routines stored at the target address of the instruction. Although the routines may not be as efficient in performing the DSP function, the program employing the function may still operate properly in the absence of the DSP. In this manner, a computer system may initially operate without the DSP included. If a user later decides to upgrade the computer system with a DSP, then the microprocessor may dispatch DSP functions to the DSP. Until the upgrade occurs, the microprocessor may execute the functions.
Abstract:
A serial communication system including a serial communication port structure for starting and stopping an internal clock. This internal clock is designed, in operation, to generate a clock output signal to be transmitted to a device external to the system in which the serial communication port is incorporated. By emitting a clock output pulse train of predetermined length, the serial communication port can effectively control the passage of time as sensed by the external device. The location of data boundaries relative to the clock phase is programmable such that the data boundaries coincide with active clock edges.
Abstract:
A method and apparatus for encrypting and decrypting a microprocessor serial number. First and second encryption keys and a serial number are provided in microprocessor machine specific registers. The serial number is encrypted using the first key. The encrypted serial number is encrypted using the second key. The first encryption key may be encrypted along with the serial number using the second key. The double-encrypted serial number is then stored in memory provided for that purpose.
Abstract:
An improved vocoder system and method for estimating pitch in a speech waveform. The method comprises an improved correlation method for estimating the pitch parameter which more accurately disregards false correlation peaks resulting from the contribution of the First Formant to the pitch estimation method. The vocoder performs a correlation calculation on a frame of the speech waveform to estimate the pitch of the frame. According to the invention, during the correlation calculation the vocoder performs calculations to determine when a transition from unvoiced to voiced speech occurs. When such a transition is detected, the vocoder widens the correlation sample window. The present invention thus determines when a transition from unvoiced to voiced speech occurs and dynamically adjusts or widens the sample window to reduce the effect of the First Formant in the pitch estimation. Once this frame and the next have been classified as voiced, the correlation sample window can be reduced to its original value. Therefore, the present invention more accurately provides the correct pitch parameter in response to a sampled speech waveform.
Abstract:
An apparatus for digital cordless telecommunications includes a frame formatter for logical channel formatting of transmitted baseband signals and received baseband signals. The apparatus comprises a radio interface connection with the frame formatter, for delivering and receiving the transmitted baseband signal and the received baseband signal, respectively, a FIFO/codec interface connected with the frame formatter, an interrupt interface connected with the frame formatter, a control register interface connected with the frame formatter, and a microcontroller interface connected with the frame formatter.
Abstract:
Method and system aspects properly enable and disable a function in a peripheral device. In a system aspect, the system includes a processing system, and a control mechanism within the peripheral device and coupled to the processing system, the control mechanism controlling enabling and disabling of a function in the peripheral device. The control mechanism further includes a decoder coupled to the processing system, and a counter coupled to the decoder. In a method aspect, the method includes receiving first and second control signals at a control mechanism in the peripheral device from at least one component in the processing system, and maintaining a state of the peripheral device at a predetermined level according to a value of the control mechanism, wherein the first and second control signals alter the value of the control mechanism.
Abstract:
A sound processing apparatus includes a plurality of microphones spaced apart from each other, each microphone producing electrical signals representative of sound signals incident thereon. The sound processing apparatus also includes a signal processing unit that produces a specific direction sound signal by processing the electrical signals according to a specific sound direction. The plurality of microphones can be positioned about a periphery of a computer display, and adaptative beam forming techniques can be employed to provide a directional input sound signal for use in sound processing.
Abstract:
A network interface transmits data packets between a host computer and a network and includes a first in first out (FIFO) buffer memory with an adaptive transmit start point determined for each data packet. The network interface receives data packets from the host computer via a peripheral component interconnect (PCI) bus. A FIFO control determines the byte length of each data packet based on the header information contained in the first few received bytes of the packet. The FIFO control also measures a minimum fill time indicating the time necessary to fill the FIFO buffer memory with a predetermined minimum amount of data necessary before transmission by the FIFO buffer memory. The FIFO control calculates the time to fill the FIFO buffer memory with each packet based on the determined length and the measured minimum fill time. The time to empty the packet from the FIFO buffer memory is also calculated based upon the length of the packet and predetermined network transmission rates. If the time to empty the packet from the FIFO buffer memory is greater than or equal to the time to fill the FIFO buffer memory, the transmit start point is set to the predetermined minimum amount; otherwise, the transmit start point is adjusted in accordance with the difference in time between filling and emptying the FIFO buffer memory with the packet, a FIFO fill rate based on the measured minimum fill time, and a coefficient that accounts for latencies in the PCI bus. The network interface thus provides an optimal transmit start point for each data packet, minimizing latency and underflow conditions during network transmission.
Abstract:
A digital to analog converter that includes circuitry that converts sequences of positive and negative digital data samples into electrical currents and current mirror circuitry that generates an analog waveform by combining and amplifying the electrical currents.
Abstract:
A floating gate diode which can be used as a sourceless memory cell, and which may be arranged into an array of memory cells is disclosed. The floating gate diode comprises: a drain region (64) formed in a substrate (62); an oxide overlying and associated with the drain region (64); and a floating gate (66) overlying the oxide. Upon application of a voltage to the drain (64), a current between the drain (64) and substrate (62) is induced in proportion to an amount of electrons stored on the gate. The cells may be arranged into an array which comprises a substrate having a surface; a plurality of drain regions, one of said drain regions respectively corresponding to one of the plurality of cells, formed in the substrate; an oxide region overlying the plurality of drain regions on the surface of the substrate; and a plurality of floating gates overlying the oxide and respectively associated with the plurality of drain regions.