Texas Instruments Corporation

National Semiconductor Corporation

Roman Staszewski

Robert Bogdan Staszewski

Fuqiang Shi

Thang M Tran

Khurram Waheed

Jingcheng Zhuang

Eric G Soenen

Thomas F Adkins

Loulis J Izzi

Thomas Casimir Murphy

Jinwen Xi

A novel and useful apparatus for and method of software based phase locked loop (PLL). The software based PLL incorporates a reconfigurable calculation unit (RCU) that is optimized and programmed to sequentially perform all the atomic operations of a PLL or any other desired task in a time sharing manner. An application specific instruction-set processor (ASIP) incorporating the RCU includes an instruction set whose instructions are optimized to perform the atomic operations of a PLL. The RCU is clocked at a fast enough processor clock rate to insure that all PLL atomic operations are performed within a single PLL reference clock cycle.

IC transmitter digital phase domain calculator with atomic computation units

Reconfigurable calculation unit with atomic computation units and control inputs

Phase domain calculator clock, ALU, memory, register file, sequencer, latches

Software reconfigurable digital phase lock loop architecture

ASIP with reconfigurable circuitry implementing atomic operations of a PLL

Transmission of information between user equipment (UE) and base stations in a wireless network occurs using a stream of periodic data. A modem in the UE operates synchronized to a first clock source to produce the stream of periodic data at a chip rate. Transceiver circuitry is synchronized to a variable clock source to receive the stream of data from the first circuitry at a rate according to the variable clock source. A fixed phase relationship is maintained between the variable clock source and the first clock source while the data period is uniform by adjusting the variable clock in response to detected phase errors. Occasionally, one period of the periodic data is changed by a defined amount. The fixed phase relationship is restored over a number of periods in a gradual manner by changing the frequency of the variable clock by an amount. By restoring the phase relationship gradually, quality degradation of the transmitted signal is reduced.

Fractional interpolative timing advance and retard control in a transceiver

A novel and useful apparatus for and method of spur reduction using computation spreading with dithering in a digital phase locked loop (DPLL) architecture. A software based PLL incorporates a reconfigurable calculation unit (RCU) that is optimized and programmed to sequentially perform all the atomic operations of a PLL or any other desired task in a time sharing manner. An application specific instruction-set processor (ASIP) incorporating the RCU is adapted to spread the computation of the atomic operations out over a PLL reference clock period wherein each computation is performed at a much higher processor clock frequency than the PLL reference clock rate. This significantly reduces the per cycle current transient generated by the computations. The frequency content of the current transients is at the higher processor clock frequency which results in a significant reduction in spurs within sensitive portions of the output spectrum. Further reduction in spurs is achieved by dithering the duration of the software loop of atomic operations and/or by randomly shuffling one or more non-data dependent instructions within each iteration of the software loop.

Computation spreading utilizing dithering for spur reduction in a digital phase lock loop

This invention is an application specific integrated processor to implement the complete fixed-rate DRX signal processing paths (FDRX) for a reconfigurable processor-based multi-mode 3G wireless application. This architecture is based on the baseline 16-bit RISC architecture with addition functional blocks (ADU) tightly coupled with the based processor's data path. Each ADU accelerates a computation-intensive tasks in FDRX signal path, such as multi-tap FIRs, IIRs, complex domain and vectored data processing. The ADUs are controlled through custom instructions based on the load/store architecture. The whole FDRX data path can be easily implemented by the software employing these custom instructions.

Application specific instruction set processor for digital radio processor receiving chain signal processing

A novel and useful apparatus for and method of spur reduction using computation spreading in a digital phase locked loop (DPLL) architecture. A software based PLL incorporates a reconfigurable calculation unit (RCU) that is optimized and programmed to sequentially perform all the atomic operations of a PLL or any other desired task in a time sharing manner. An application specific instruction-set processor (ASIP) incorporating the RCU is adapted to spread the computation of the atomic operations out over and completed within an entire PLL reference clock period. Each computation being performed at a much higher processor clock frequency than the PLL reference clock rate. This functions to significantly reduce the per cycle current transient generated by the computations. Further, the frequency content of the current transients is at the higher processor clock frequency. This results in a significant reduction in spurs within sensitive portions of the output spectrum.

Computation spreading for spur reduction in a digital phase lock loop

A novel and useful apparatus for and method of software based phase locked loop (PLL). The software based PLL incorporates a reconfigurable calculation unit (RCU) that is optimized and programmed to sequentially perform all the atomic operations of a PLL or any other desired task in a time sharing manner. An application specific instruction-set processor (ASIP) incorporating the RCU includes an instruction set whose instructions are optimized to perform the atomic operations of a PLL. A multi-stage data stream based processor incorporates a parallel/pipelined architecture optimized to perform data stream processing efficiently. The multi-stage parallel/pipelined processor provides significantly higher processing speeds by combining multiple RCUs wherein input data samples are input in parallel to all RCUs while computation results from one RCU are used by adjacent downstream RCUs. A register file provides storage for historical values while local storage in each RCU provides storage for temporary results.

Computation parallelization in software reconfigurable all digital phase lock loop

An improved electrically erasable read only memory (EEPROM) includes a EEPROM cell and a static random access memory (SRAM) cell. Complementary pairs of complementary metal oxide semiconductor (CMOS) transistors connect the gates of transistors forming the EEPROM cell to either the corresponding data nodes of the SRAM cell or to a fixed read or nonzero test voltage. When formed into an array, it is not necessary to replicate differential sense circuitry in every cell. EEPROM transistor pairs are combined into columns which share a common sense latch. The nonsero test voltage allows for measurement of the actual threshold voltages (V.sub.T) of each EEPROM device individually.

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McKinney, TX, United States of America

Roman Staszewski