The automation process is a very important pillar for Industry 4.0.One of the first steps is the control of motors to improve production efficiency and generate energy savings.In mass production industries,techniques ...The automation process is a very important pillar for Industry 4.0.One of the first steps is the control of motors to improve production efficiency and generate energy savings.In mass production industries,techniques such as digital signal processing(DSP)systems are implemented to control motors.These systems are efficient but very expensive for certain applications.From this arises the need for a controller capable of handling AC and DC motors that improves efficiency and maintains low energy consumption.This project presents the design of an adaptive control system for brushless AC induction and DC motors,which is functional to any type of plant in the industry.The design was possible by implementing Matlab software and tools such as digital signal processor(DSP)and Simulink.Through an extensive investigation of the state of the art,three models needed to represent the control system have been specified.The first model for the AC motor,the second for the DC motor and the third for the DSP control;this is done in this way so that the probability of failure is lower.Subsequently,these models have been programmed in Simulink,integrating the three main models into one.In this way,the design of a controller for use in AC induction motors,specifically squirrel cage and brushless DC motors,has been achieved.The final model represents a response time of 0.25 seconds,which is optimal for this type of application,where response times of 2e-3 to 3 seconds are expected.展开更多
A fuzzy logic intelligent control system of pulsed MAG welding inverter based on digital signal processor (DSP) is proposed to obtain the consistency of arc length in pulsed MAG welding. The proposed control system ...A fuzzy logic intelligent control system of pulsed MAG welding inverter based on digital signal processor (DSP) is proposed to obtain the consistency of arc length in pulsed MAG welding. The proposed control system combines the merits of intelligent control with DSP digital control. The fuzzy logic intelligent control system designed is a typical two-input-single-output structure, and regards the error and the change in error of peak arc voltage as two inputs and the background time as single output. The fuzzy logic intelligent control system is realized in a look-up table (LUT) method by using MATLAB based fuzzy logic toolbox, and the implement of LUT method based on DSP is also discussed. The pulsed MAG welding experimental results demonstrate that the developed fuzzy logic intelligent control system based on DSP has strong arc length controlling ability to accomplish the stable pulsed MAG welding process and controls pulsed MAG welding inverter digitally and intelligently.展开更多
The relativity of instructions of motor control digital signal processor (MCDSP) in the design is analyzed. A method for obtaining a minimum instruction set in plac e of the complete instruction set during generatio...The relativity of instructions of motor control digital signal processor (MCDSP) in the design is analyzed. A method for obtaining a minimum instruction set in plac e of the complete instruction set during generation of testing procedures is giv en in terms of the processor presentation matrix between micro-operators and in structions of MCDSP.展开更多
This paper presents an optimized implementation of the FDK algorithm on a single fixed-point TMS320C6455 digital signal processor (DSP). Software pipelining and proper configuration of the data transfer enables a 25...This paper presents an optimized implementation of the FDK algorithm on a single fixed-point TMS320C6455 digital signal processor (DSP). Software pipelining and proper configuration of the data transfer enables a 2563 volume to be reconstructed in about 42 seconds from 360 projections with very good accuracy. This implementation reveals the potential of modern high-performance DSPs in accelerating image reconstruction, especially when cost and power consumption are emphasized.展开更多
Satellite signal simulator for global navigation satellite system(GNSS)can evaluate the accuracy of capturing,tracing and positioning of GNSS receiver.It has significant use-value in the military and civil fields.The ...Satellite signal simulator for global navigation satellite system(GNSS)can evaluate the accuracy of capturing,tracing and positioning of GNSS receiver.It has significant use-value in the military and civil fields.The system adopts the overall design scheme of digital signal processor(DSP)and field-programmable gate array(FPGA).It consists of four modules:industrial control computer simulation software,mid-frequency signal generator,digital-to-analog(D/A)module and radio frequency(RF)module.In this paper,we test the dynamic performance of simulator using the dynamic scenes testing method,and the signal generated by the designed simulator is primarily validated.展开更多
A digital control of pulsed gas metal arc welding inverter was proposed. A control system consisting of analogue parts was replaced with a new digital control implemented in a TMS320LF2407A DSP chip. The design and co...A digital control of pulsed gas metal arc welding inverter was proposed. A control system consisting of analogue parts was replaced with a new digital control implemented in a TMS320LF2407A DSP chip. The design and constructional features of the whole digital control were presented. The resources of the DSP chip were efficiently utilized and the circuits are very concise, which can enhance the stability and reliability of welding inverter. Experimental results demonstrate that the developed digital control has the ability to accomplish the excellent pulsed gas metal arc welding process and the merits of the developed digital control are stable welding process, little spatter and perfect weld appearance.展开更多
An important issue of ground-penetrating radar (GPR) signals analysis is de-noising thai is the guarantee of acquiring good detecting effect. The paper illustrates a successful application of digital single process...An important issue of ground-penetrating radar (GPR) signals analysis is de-noising thai is the guarantee of acquiring good detecting effect. The paper illustrates a successful application of digital single processor (DSP) based on wavelet shrinkage algorithm. In order to realize real-time GPP, signals analysis, some key issues are discussed such as the realization of fast wavelet transformation, the selection of CPU chip and the optimization of data movement. Experimenial results show that the DSP based application not only basically meets the real-time requirement of GPP, signals analysis, but also assures the quality of the GPR signals analysis.展开更多
A novel inverter power source is developed characterized with constant output current and unit power factor input. Digital signal processor ( DSP ) is used to realize power factor correction and control of back-stag...A novel inverter power source is developed characterized with constant output current and unit power factor input. Digital signal processor ( DSP ) is used to realize power factor correction and control of back-stage inverter bridge of the arc welding inverter. The fore-stage adopts double closed loop proportion and integration (PI) rectifier technique and the back- stage adopts digital pulse width modulation ( PWM) technique. Simulated waves can be obtained in Matlab/Simulink and validated by experiments. Experiments of the prototype showed that the total harmonic distortion (THD) can be controlled within 10% and the power factor is approximate to 1.展开更多
A new type of variable polarity welding power modulated with high-frequency pulse current is developed. Series of high-frequency pulse current is superimposed on direct-current-electrode-negative (DCEN), which can i...A new type of variable polarity welding power modulated with high-frequency pulse current is developed. Series of high-frequency pulse current is superimposed on direct-current-electrode-negative (DCEN), which can improve the crystallization process in the weld bead as a result of the electromagnetic force generated by pulse current. Digital signal processor (DSP) is used to realize the closed-loop control of the first inverter, variable polarity output of the second inverter and high-frequency pulse current superposition.展开更多
The transistor voltage regulators have been widely adopted in the brushless AC generators in aircraft. This paper researches the digital voltage regulator. The paper presents the hardware platform of the digital volta...The transistor voltage regulators have been widely adopted in the brushless AC generators in aircraft. This paper researches the digital voltage regulator. The paper presents the hardware platform of the digital voltage regulator, which is based on a DSP chip — TMS320C32. A novel fuzzy filter control structure is developed from normal fuzzy control strategy. And the fuzzy filter control algorithm is adopted in the hardware platform successfully. The computer simulation has been conducted. Some control parameters have been obtained through the simulation. The same parameters have been applied in the digital regulation experiments on a brushless AC generator. In the experiment, the digital voltage regulator results in good responses. From the experiment results, it can be seen that the new control algorithm is efficient for the digital voltage regulator.展开更多
Digital design of a digital signal processor involves accurate and high-speed mathematical computation units.DSP units are one of the most power consuming and memory occupying devices.Multipliers are the common buildi...Digital design of a digital signal processor involves accurate and high-speed mathematical computation units.DSP units are one of the most power consuming and memory occupying devices.Multipliers are the common building blocks in most of the DSP units which demands low power and area constraints in the field of portable biomedical devices.This research works attempts multiple power reduction technique to limit the power dissipation of the proposed LUT multiplier unit.A lookup table-based multiplier has the advantage of almost constant area requirement’s irrespective to the increase in bit size of multiplier.Clock gating is usually used to reduce the unnecessary switching activities in idle circlet components.A clock tree structure is employed to enhance the SRAM based lookup table memory architecture.The LUT memory access operation is sequential in nature and instead of address decoder a ring counter is used to scan the memory contents and gated driver tree structure is implemented to control the clock and data switching activities.The proposed algorithm yields 20%of power reduction than existing.展开更多
A new design of vision based soccer robot using the type TMS320F240 of DSPs for MiroSot series is presented. The DSP used enables cost effective control of DC motor, and features fewer external components, lower syste...A new design of vision based soccer robot using the type TMS320F240 of DSPs for MiroSot series is presented. The DSP used enables cost effective control of DC motor, and features fewer external components, lower system cost and better performances than traditional microcontroller. The hardware architecture of robot is firstly presented in detail, and then the software design is briefly discussed. The control structure of decision making subsystem is illuminated also in this paper. The conclusion and prospect are given at last.展开更多
According to the algorithm of the fuze antenna beamforming and the requirement for the realtime performenee, a fuze antenna beamformer based on digital signal processor (DSP) was designed. The program was written in...According to the algorithm of the fuze antenna beamforming and the requirement for the realtime performenee, a fuze antenna beamformer based on digital signal processor (DSP) was designed. The program was written in C, and in order to reduce the operation time of DSP, the key part of the matrix operation was written in simple algorithm. The precise and speediness of DSP calculation results were analyzed through Matlab and the Profiling tools in Code Composer Studio (CCS). The results show that the precise and the speediness both can satisfy the requirement for the fuze antennh beamforming.展开更多
An audiobeam loudspeaker system based on the fixed-point digital signal processor(DSP)TMS320VC5509A(VC5509A for short)is developed to emit audible sound with high directivity along a selected path.This system is compo...An audiobeam loudspeaker system based on the fixed-point digital signal processor(DSP)TMS320VC5509A(VC5509A for short)is developed to emit audible sound with high directivity along a selected path.This system is composed of preamplifier,anti-aliasing filter,ADC(analog to digital converter),VC5509A basic system,DAC(digital to analog converter),smoothing filter,ultrasonic power amplifier and ultrasonic transducer array.VC5509A is used to implement the key signal preprocessing algorithms,such as signal preprocessing,amplitude modulation,carrier signal generator,etc.The experiments show that this system has the advantages of high accuracy and good stability.展开更多
A kind of pseudo Gray code presentation of test patterns based on accumulation generators is presented and a low power test scheme is proposed to test computational function modules with contiguous subspace in very la...A kind of pseudo Gray code presentation of test patterns based on accumulation generators is presented and a low power test scheme is proposed to test computational function modules with contiguous subspace in very large scale integration (VLSI), especially in digital signal processors (DSP). If test patterns from accumulators for the modules are encoded in the pseudo Gray code presentation, the switching activities of the modules are reduced, and the decrease of the test power consumption is resulted in. Results of experimentation based on FPGA show that the test approach can reduce dynamic power consumption by an average of 17.40% for 8-bit ripple carry adder consisting of 3-2 counters. Then implementation of the low power test in hardware is exploited. Because of the reuse of adders, introduction of additional XOR logic gates is avoided successfully. The design minimizes additional hardware overhead for test and needs no adjustment of circuit structure. The low power test can detect any combinational stuck-at fault within the basic building block without any degradation of original circuit performance.展开更多
In this paper, we present an optimized design method for high-speed embedded image processing system using 32 bit floating-point Digital Signal Processor (DSP) and Complex Programmable Logic Device (CPLD). The DSP...In this paper, we present an optimized design method for high-speed embedded image processing system using 32 bit floating-point Digital Signal Processor (DSP) and Complex Programmable Logic Device (CPLD). The DSP acts as the main processor of the system: executes digital image processing algorithms and operates other devices such as image sensor and CPLD. The CPLD is used to acquire images and achieve complex logic control of the whole system. Some key technologies are introduced to enhance the performance of our system. In particular, the use of DSP/BIOS tool to develop DSP applications makes our program run much more efficiently. As a result, this system can provide an excellent computing platform not only for executing complex image processing algorithms, but also for other digital signal processing or multi-channel data collection by choosing different sensors or Analog-to-Digital (A/D) converters.展开更多
A novel and simple ifrea! control algorithm using digital signal processor (DSP) has been proposed and realized for a three phase shunt active filter (SAF). The simulation and prototype construction of SAF is cond...A novel and simple ifrea! control algorithm using digital signal processor (DSP) has been proposed and realized for a three phase shunt active filter (SAF). The simulation and prototype construction of SAF is conducted to compensate the reactive power and harmonics in a distribution system. The major feature of the proposed ifreal algorithm is that it does not require unit vector templates and any transformations for the reference current genera- tion of SAF. This reduces the computational complexity and makes the control flexible and faster. The simulation is conducted in MATLAB/SIMULINK while DSP TMS320LF2407 is employed in the digital implementation of hysteresis current control (HCC) for experimentation. The hardware results correlate with the simulation results in reducing the total harmonic distortion (THD) of the source current and achieving unity power factor.展开更多
The cost of the central register file and the size of the program code limit the scalability of very long instruction word(VLIW) processors with increasing numbers of functional units.This paper presents the archite...The cost of the central register file and the size of the program code limit the scalability of very long instruction word(VLIW) processors with increasing numbers of functional units.This paper presents the architectural design of a six-way VLIW digital signal processor(DSP) with clustered register files.The architecture uses a variable length instruction set and supports dynamic instruction dispatching.The one-level memory system architecture of the processor includes 16-KB instruction and data caches and 16-KB instruction and data on-chip RAM.A compiler based on the Open64 was developed for the system.Evaluations show that the processor is suitable for high performance applications with a high code density and small program code size.展开更多
We demonstrate a scheme to use a Littman configuration external cavity diode laser (ECDL) as a stablefrequency light source to stabilize two cw single-mode Ti:sapphire lasers for laser cooling of magnesium fluoride...We demonstrate a scheme to use a Littman configuration external cavity diode laser (ECDL) as a stablefrequency light source to stabilize two cw single-mode Ti:sapphire lasers for laser cooling of magnesium fluoride molecules. An ECDL based on the Littman configuration is constructed and stabilized by a digital signal processor system. We stabilize the frequency of our ECDL to 4-0.77 MHz precision over 10 h and the Allan standard deviation reaches 2.6 × 10-11 at an integration time of 10 s. We lock two Ti:sapphire lasers through a transfer cavity, and either laser has a long-term frequency stability of 4-2.5 MHz.展开更多
文摘The automation process is a very important pillar for Industry 4.0.One of the first steps is the control of motors to improve production efficiency and generate energy savings.In mass production industries,techniques such as digital signal processing(DSP)systems are implemented to control motors.These systems are efficient but very expensive for certain applications.From this arises the need for a controller capable of handling AC and DC motors that improves efficiency and maintains low energy consumption.This project presents the design of an adaptive control system for brushless AC induction and DC motors,which is functional to any type of plant in the industry.The design was possible by implementing Matlab software and tools such as digital signal processor(DSP)and Simulink.Through an extensive investigation of the state of the art,three models needed to represent the control system have been specified.The first model for the AC motor,the second for the DC motor and the third for the DSP control;this is done in this way so that the probability of failure is lower.Subsequently,these models have been programmed in Simulink,integrating the three main models into one.In this way,the design of a controller for use in AC induction motors,specifically squirrel cage and brushless DC motors,has been achieved.The final model represents a response time of 0.25 seconds,which is optimal for this type of application,where response times of 2e-3 to 3 seconds are expected.
基金supported by National Natural Science Foundation of China(No.50375054)China Postdoctoral Science Foundation (No.20060400745).
文摘A fuzzy logic intelligent control system of pulsed MAG welding inverter based on digital signal processor (DSP) is proposed to obtain the consistency of arc length in pulsed MAG welding. The proposed control system combines the merits of intelligent control with DSP digital control. The fuzzy logic intelligent control system designed is a typical two-input-single-output structure, and regards the error and the change in error of peak arc voltage as two inputs and the background time as single output. The fuzzy logic intelligent control system is realized in a look-up table (LUT) method by using MATLAB based fuzzy logic toolbox, and the implement of LUT method based on DSP is also discussed. The pulsed MAG welding experimental results demonstrate that the developed fuzzy logic intelligent control system based on DSP has strong arc length controlling ability to accomplish the stable pulsed MAG welding process and controls pulsed MAG welding inverter digitally and intelligently.
文摘The relativity of instructions of motor control digital signal processor (MCDSP) in the design is analyzed. A method for obtaining a minimum instruction set in plac e of the complete instruction set during generation of testing procedures is giv en in terms of the processor presentation matrix between micro-operators and in structions of MCDSP.
文摘This paper presents an optimized implementation of the FDK algorithm on a single fixed-point TMS320C6455 digital signal processor (DSP). Software pipelining and proper configuration of the data transfer enables a 2563 volume to be reconstructed in about 42 seconds from 360 projections with very good accuracy. This implementation reveals the potential of modern high-performance DSPs in accelerating image reconstruction, especially when cost and power consumption are emphasized.
基金Shanxi Provincial Science and Technology Research Fund(No.2012021013-6)
文摘Satellite signal simulator for global navigation satellite system(GNSS)can evaluate the accuracy of capturing,tracing and positioning of GNSS receiver.It has significant use-value in the military and civil fields.The system adopts the overall design scheme of digital signal processor(DSP)and field-programmable gate array(FPGA).It consists of four modules:industrial control computer simulation software,mid-frequency signal generator,digital-to-analog(D/A)module and radio frequency(RF)module.In this paper,we test the dynamic performance of simulator using the dynamic scenes testing method,and the signal generated by the designed simulator is primarily validated.
基金Supported by National Natural Science Foundation of China ( No50375054)China Postdoctoral Science Foundation ( No20060400745)
文摘A digital control of pulsed gas metal arc welding inverter was proposed. A control system consisting of analogue parts was replaced with a new digital control implemented in a TMS320LF2407A DSP chip. The design and constructional features of the whole digital control were presented. The resources of the DSP chip were efficiently utilized and the circuits are very concise, which can enhance the stability and reliability of welding inverter. Experimental results demonstrate that the developed digital control has the ability to accomplish the excellent pulsed gas metal arc welding process and the merits of the developed digital control are stable welding process, little spatter and perfect weld appearance.
基金Supported by the National Natural Science Founda-tion of China (49984001)
文摘An important issue of ground-penetrating radar (GPR) signals analysis is de-noising thai is the guarantee of acquiring good detecting effect. The paper illustrates a successful application of digital single processor (DSP) based on wavelet shrinkage algorithm. In order to realize real-time GPP, signals analysis, some key issues are discussed such as the realization of fast wavelet transformation, the selection of CPU chip and the optimization of data movement. Experimenial results show that the DSP based application not only basically meets the real-time requirement of GPP, signals analysis, but also assures the quality of the GPR signals analysis.
文摘A novel inverter power source is developed characterized with constant output current and unit power factor input. Digital signal processor ( DSP ) is used to realize power factor correction and control of back-stage inverter bridge of the arc welding inverter. The fore-stage adopts double closed loop proportion and integration (PI) rectifier technique and the back- stage adopts digital pulse width modulation ( PWM) technique. Simulated waves can be obtained in Matlab/Simulink and validated by experiments. Experiments of the prototype showed that the total harmonic distortion (THD) can be controlled within 10% and the power factor is approximate to 1.
文摘A new type of variable polarity welding power modulated with high-frequency pulse current is developed. Series of high-frequency pulse current is superimposed on direct-current-electrode-negative (DCEN), which can improve the crystallization process in the weld bead as a result of the electromagnetic force generated by pulse current. Digital signal processor (DSP) is used to realize the closed-loop control of the first inverter, variable polarity output of the second inverter and high-frequency pulse current superposition.
基金Pre-research subject of the 9-th 5 year plan for National Defenc
文摘The transistor voltage regulators have been widely adopted in the brushless AC generators in aircraft. This paper researches the digital voltage regulator. The paper presents the hardware platform of the digital voltage regulator, which is based on a DSP chip — TMS320C32. A novel fuzzy filter control structure is developed from normal fuzzy control strategy. And the fuzzy filter control algorithm is adopted in the hardware platform successfully. The computer simulation has been conducted. Some control parameters have been obtained through the simulation. The same parameters have been applied in the digital regulation experiments on a brushless AC generator. In the experiment, the digital voltage regulator results in good responses. From the experiment results, it can be seen that the new control algorithm is efficient for the digital voltage regulator.
文摘Digital design of a digital signal processor involves accurate and high-speed mathematical computation units.DSP units are one of the most power consuming and memory occupying devices.Multipliers are the common building blocks in most of the DSP units which demands low power and area constraints in the field of portable biomedical devices.This research works attempts multiple power reduction technique to limit the power dissipation of the proposed LUT multiplier unit.A lookup table-based multiplier has the advantage of almost constant area requirement’s irrespective to the increase in bit size of multiplier.Clock gating is usually used to reduce the unnecessary switching activities in idle circlet components.A clock tree structure is employed to enhance the SRAM based lookup table memory architecture.The LUT memory access operation is sequential in nature and instead of address decoder a ring counter is used to scan the memory contents and gated driver tree structure is implemented to control the clock and data switching activities.The proposed algorithm yields 20%of power reduction than existing.
文摘A new design of vision based soccer robot using the type TMS320F240 of DSPs for MiroSot series is presented. The DSP used enables cost effective control of DC motor, and features fewer external components, lower system cost and better performances than traditional microcontroller. The hardware architecture of robot is firstly presented in detail, and then the software design is briefly discussed. The control structure of decision making subsystem is illuminated also in this paper. The conclusion and prospect are given at last.
基金the Ministerial Level Advanced Research Foundation(51204BQ01)
文摘According to the algorithm of the fuze antenna beamforming and the requirement for the realtime performenee, a fuze antenna beamformer based on digital signal processor (DSP) was designed. The program was written in C, and in order to reduce the operation time of DSP, the key part of the matrix operation was written in simple algorithm. The precise and speediness of DSP calculation results were analyzed through Matlab and the Profiling tools in Code Composer Studio (CCS). The results show that the precise and the speediness both can satisfy the requirement for the fuze antennh beamforming.
基金Science and Technology Development Plan of Shandong Province(No.2010GSF10809)
文摘An audiobeam loudspeaker system based on the fixed-point digital signal processor(DSP)TMS320VC5509A(VC5509A for short)is developed to emit audible sound with high directivity along a selected path.This system is composed of preamplifier,anti-aliasing filter,ADC(analog to digital converter),VC5509A basic system,DAC(digital to analog converter),smoothing filter,ultrasonic power amplifier and ultrasonic transducer array.VC5509A is used to implement the key signal preprocessing algorithms,such as signal preprocessing,amplitude modulation,carrier signal generator,etc.The experiments show that this system has the advantages of high accuracy and good stability.
基金supported by the National Natural Science Foundation of China under Grant No.90407007University Science Foundation of China under Grant No R0820207
文摘A kind of pseudo Gray code presentation of test patterns based on accumulation generators is presented and a low power test scheme is proposed to test computational function modules with contiguous subspace in very large scale integration (VLSI), especially in digital signal processors (DSP). If test patterns from accumulators for the modules are encoded in the pseudo Gray code presentation, the switching activities of the modules are reduced, and the decrease of the test power consumption is resulted in. Results of experimentation based on FPGA show that the test approach can reduce dynamic power consumption by an average of 17.40% for 8-bit ripple carry adder consisting of 3-2 counters. Then implementation of the low power test in hardware is exploited. Because of the reuse of adders, introduction of additional XOR logic gates is avoided successfully. The design minimizes additional hardware overhead for test and needs no adjustment of circuit structure. The low power test can detect any combinational stuck-at fault within the basic building block without any degradation of original circuit performance.
基金Supported by the National Natural Science Foundation of China (No.60472046)
文摘In this paper, we present an optimized design method for high-speed embedded image processing system using 32 bit floating-point Digital Signal Processor (DSP) and Complex Programmable Logic Device (CPLD). The DSP acts as the main processor of the system: executes digital image processing algorithms and operates other devices such as image sensor and CPLD. The CPLD is used to acquire images and achieve complex logic control of the whole system. Some key technologies are introduced to enhance the performance of our system. In particular, the use of DSP/BIOS tool to develop DSP applications makes our program run much more efficiently. As a result, this system can provide an excellent computing platform not only for executing complex image processing algorithms, but also for other digital signal processing or multi-channel data collection by choosing different sensors or Analog-to-Digital (A/D) converters.
文摘A novel and simple ifrea! control algorithm using digital signal processor (DSP) has been proposed and realized for a three phase shunt active filter (SAF). The simulation and prototype construction of SAF is conducted to compensate the reactive power and harmonics in a distribution system. The major feature of the proposed ifreal algorithm is that it does not require unit vector templates and any transformations for the reference current genera- tion of SAF. This reduces the computational complexity and makes the control flexible and faster. The simulation is conducted in MATLAB/SIMULINK while DSP TMS320LF2407 is employed in the digital implementation of hysteresis current control (HCC) for experimentation. The hardware results correlate with the simulation results in reducing the total harmonic distortion (THD) of the source current and achieving unity power factor.
基金Supported by the National Natural Science Foundation of China (No.60236020)the Specialized Research Fund for the Doctoral Program of Higher Education of MOE,China (No.20050003083)
文摘The cost of the central register file and the size of the program code limit the scalability of very long instruction word(VLIW) processors with increasing numbers of functional units.This paper presents the architectural design of a six-way VLIW digital signal processor(DSP) with clustered register files.The architecture uses a variable length instruction set and supports dynamic instruction dispatching.The one-level memory system architecture of the processor includes 16-KB instruction and data caches and 16-KB instruction and data on-chip RAM.A compiler based on the Open64 was developed for the system.Evaluations show that the processor is suitable for high performance applications with a high code density and small program code size.
基金supported by the National Natural Science Foundation of China(Nos.11374100,91536218,and 11274114)the Natural Science Foundation of Shanghai Municipality(No.13ZR1412800)
文摘We demonstrate a scheme to use a Littman configuration external cavity diode laser (ECDL) as a stablefrequency light source to stabilize two cw single-mode Ti:sapphire lasers for laser cooling of magnesium fluoride molecules. An ECDL based on the Littman configuration is constructed and stabilized by a digital signal processor system. We stabilize the frequency of our ECDL to 4-0.77 MHz precision over 10 h and the Allan standard deviation reaches 2.6 × 10-11 at an integration time of 10 s. We lock two Ti:sapphire lasers through a transfer cavity, and either laser has a long-term frequency stability of 4-2.5 MHz.