Pcm Digital Decoding System Based On Fpga Design

Developed semiconductor- technology makes digital- technology be used widely, and traditional computer,communication,consumption products gradually use the same kind of digital- technology. Now some complicated DSP modules can be carried out by FPGA. Traditionally, DSP arithmetic uses general programmable DSP parts to reach low-speed application, and uses DSP special chips and integrate circuits to reach high-speed application. DSP designing engineers are given new choices by making use of the excellence of FPGA——it has the function similar to ASIC and solves the problem that ASIC costs much to explore and the products can't be amended. While the designing methods of VHDL have the peculiarities of non-depending of parts,easily being transplanted and accelerating designing. Moreover, once VHDL is combined with FPGA amending design on the spot, it can greatly improve the efficiency and agility of design, shorten the cycle of developing , accelerate the products to come into the market. The designing method VHDL+FPGA is the innovation of digital system design and the developing direction in the future.The paper particularly shows all kinds of designing methods of digital system,the excellence and shortcomings of VHDL, explains the on-the-spot programmable parts and emphasizes the products made by XILINX, then discusses the superiority of the designing method VHDL+FPGA in the more and more complex digital integrate system ,the process designing a DSP function module by VHDL+FPGA:the ISE soft wares of exploring FOUNDATION series,the process of writing source listing using VHDL(including the explanation of the system's two sections and the VHDL program of the sub-modules),setting up the FPGA peripheral hardware circuits,the structure of FPGA downloading system and the principle of the whole system, etc. After this, the paper says what one has learned in the designing (including issues to be paid attention to in the VHDL program and the discussions of how to design better circuits by VHDL program). At last, it takes into account the further design and makes a summarize .