1. Field of the Invention
The present invention relates to a digital signal processor (DSP); in particular, the present invention relates to a DSP having the feature of power-saving.
2. Description of Related Art
In the era of information technology, demands for signal processing increase more and more. General-purpose processors usually are not capable of completing high-speed and complicated signal processing operations, therefore, the digital signal processor is developed to specifically deal with such tasks. The DSP is directed to performance of real-time operations on digitized signals; such operations may include signal filtering, mixing and comparing and the like.
The DSP can be not only programmable, but the in-field operation rate thereof may reach up to tens of millions of complex instructions per second which is far beyond the ability of commonly used microprocessors, playing a role of the critical chips in modern digitized electronic world. The conventional DSP also needs higher clocks in performing high-speed data processing, which may not only require massive amount of electricity, but power consumption must be much higher. In order to solve the above-said power consumption problem, the industry has made significant efforts to develop technologies enabling better power-saving effect in DSP.
Furthermore, currently available electronic applications mostly require portability and emphasize the ability to operate under a condition of limited power source; even for electronic products having stable power supply, and the demands on issues such as environment protection and power-saving are highlighted as well. Therefore, the technologies in the field of DSP have to advance toward low energy consumption.
In accordance with the prediction of Gene's Law, the trend regarding to energy consumption reductions in the DSP along the evolution of manufacture processes will augment one tenth in every 5 years. Actually, conventional DSP power-saving technologies are essentially based on dynamic adjustments on the operating clock and the operation voltage of the DSP; whereas, inasmuch as differences exist in various applications of the DSP, although switching the DSP among differing operating frequencies and voltages according to the DSP applications indeed reduces the power consumption, the effect thereof may be limited.
For example, currently available DSPs can be roughly categorized as 8-bit, 16-bit and 32-bit DSPs. When a 32-bit DSP receives an instruction for 16 bits, each of the components installed inside of such a DSP will start to run the instruction of 16-bit, however, the redundant components of the DSP never rest idle. Thus the aforementioned status causes unnecessary power consumption.
In brief, there are some disadvantages in the conventional technologies as follows:
1. Incapable of effectively controlling the number of transistors required while the DSP work.
2. Unable to arrange the resources precisely according to instruction and data.
In view of the above, what is desired is an improved DSP that is efficient and power-saving.