Digital Integrating Circuit Design Of SECAM Decoder In Color Television Systems

The method used in SECAM decoder in this article is not as the same as the traditional analog method, but based on digital design. Convert analog signal to digital signal using an ADC first, then decode the digital signal in digital integrating circuit. The output data of the decoder can be converted to any video format that we need. According to the design flow of digital integrating circuit, and also considering the hardware implement, we design the algorithm using Matlab first, after we get the proper picture quality that we need, we will write C code, Verilog code, then do simulation, which will be compared with Matlab result and C result. If the simulation succeeds, we'll do synthesis and FPGA verification. At last, we get the proper picture from FPGA, the design pass the FPGA verification.There are some innovated algorithms in the design. First, using a new corrective method in color signal detection, and also a method of assume first then corrective which can avoid the bad picture quality as a result of the assumption failing. Besides this, considering the relation between sampling rate, system clock and sub carrier when we decide sampling rate and system clock, we can make some design much more simple, such as FFT, CORDIC and so on, using little area but have no bad effect on the timing and the picture quality.After we finish the hdl coding and simulation, we'll do FPGA verification. As the performance of FPGA will be much worse than the real chip, we have confidence that we can succeed, if we pass FPGA verification. So we set up a complex FPGA verification plat form to verify the design. At last, we pass the verification and get the proper picture, so the design should be right.There are many years after SECAM was invented, but using digital integrating circuit to demodulate it just appears recently. Along with the development of micro -electronics, digital integrating circuit will be used more and more, and also the digital integrating circuit of TV decoder will be used more and more, it will be the matting of Digital TV in future.