摘要:
A dual mode transmitter for GSM and UMTS operation is provided. The GSM and UMTS paths share an oscillator and an intermediate frequency stage. Also, with the exception of the final stage of power amplification, the transmitter is provided as an integrated device.
摘要:
A homodyne receiver is provided for receiving GSM and UMTS transmissions. The receiver may also be used for other transmission schemes. The receiver includes an electronically reconfigurable low pass filter and an off set generator for providing DC offset correction for offsets which may be generated as a result of coupling between a local radio frequency oscillator and the receiver front end.
摘要:
A radio transceiver suitable for use in a mobile telephone is provided. The transceiver is operable in dual modes so as to be able to operate with both GSM and UMTS systems. In a preferred embodiment the transmitter section receives base band signals and up-converts them to an intermediate frequency of approximately 450 MHz. This is then mixed with local oscillator frequency of approximately 1.35 GHz, such that a difference frequency allows operation in the GSM 850/950 MHz band, and the sum frequency allows operation in the GSM 1800/1900 MHz bands. The frequency addition allows operation in the UMTS band. The receiver portion of the transceiver comprises a direct conversion receiver for down-converting the received signal without use of an intermediate frequency.
摘要:
A multiple bus architecture includes multiple processors, and one or more shared peripherals such as memory. The architecture includes plural bus masters, each connected to its own bus. There are also plural bus slaves, each connected to its own bus. A bus arbitration module selectively interconnects the buses, so that when the plural bus masters each access a different bus slave, no blocking occurs, and when the plural bus masers each access a same bus slave, bandwidth starvation is avoided. The architecture is supported by a bus arbitration method including hierarchical application of an interrupt-based method, an assigned slot rotation method and a round-robin method, which avoids both bandwidth starvation and lockout during extended periods of bus contention.
摘要:
A dynamic power controller is provided that identifies a clock frequency requirement of a processor and determines a voltage requirement to support the clock frequency requirement. The dynamic power controller transitions the processor to a power state defined by the clock frequency requirement and the voltage requirement. In particular, a voltage level indicated by the voltage requirement is supplied to the processor and the frequency distribution indicated by the frequency requirement is provided to the clocks signals of the processor.
摘要:
A timing system is disclosed for use in a wireless communication system that includes wireless transceiver and a digital baseband processing system. The timing system includes a primary clock generation system that provides a low frequency clock that is used as the reference clock for a digital signal processing system, which generates low frequency timing signals, and a secondary clock generation system that provides a high frequency clock that is used by the wireless transceiver to produce high resolution timing signals to control the timing of the wireless transceiver. The high resolution timing signals are commenced responsive to a low resolution timing signal.
摘要:
A timing system is disclosed for use in a wireless communication system that includes wireless transceiver and a digital baseband processing system. The timing system includes a primary clock generation system that provides a low frequency clock that is used as the reference clock for a digital signal processing system, which generates low frequency timing signals, and a secondary clock generation system that provides a high frequency clock that is used by the wireless transceiver to produce high resolution timing signals to control the timing of the wireless transceiver. The high resolution timing signals are commenced responsive to a low resolution timing signal.
摘要:
Methods and apparatus are provided for operating an embedded processor system that includes a processor and a cache memory. The method includes filling one or more lines in the cache memory with data associated with a first task, executing the first task, and, in response to a cache miss during execution of the first task, performing a cache line fill operation and, during the cache line fill operation, executing a second task. The cache memory may notify the processor of the line fill operation by generating a processor interrupt or by notifying a task scheduler running on the processor.
摘要:
The present invention is directed to methods and apparatus which may be used to help prevent electronic devices, including cell phones, from operating with software copied from (and only authorized for use by or on) another device. A further aspect is a device, including a cell phone, for example, that employs any of such methods and apparatus. Aspects of the present invention compare a program identifier (associated with software stored in a device) to a reference identifier for the device, so as to determine whether the software is authorized for use with that device. Some embodiments respond to the comparison substantially in hardware, so that the software being checked is less able to prevent the device from being disabled in the event that the program identifier and the reference identifier do not match one another.
摘要:
Methods and apparatus are provided for spread spectrum signal processing in a wireless communication system. The apparatus includes a control processor to generate commands for processing spread spectrum signal components and a reconfigurable coprocessor to process the spread spectrum signal components based on the commands and to provide reports to the control processor based on results of processing the signal components.