Integrated Design Of 20-Line Field Telephone Exchange Based On The Architecture Of MCU+CPLD/FPGA

Wired communication method is attached importance to the military because of its high secrecy and anti-jamming. So it's of great strategic value to make applied researches on military wired communication service. TBJ-204 20-Line Field Telephone Exchange is a minitype backpacking analogy space division interchange PABX. It has been playing an important role in equipping all kinds of arms and services for campaigns, tactical exercises and emergent actions etc.Based on the detailed analysis of the exchange's architecture and implementing, this thesis points out some disadvantages of the device, such as too many absolute components, not very high enough reliability and security, very large size and weight, operating and maintaining difficultly. Considering low power requirement and man-machine interface optimizing design at the same time, the thesis come up with an integrated design scheme to the previous device based on "MCU+CPLD/FPGA Architecture": (1)Signal frequency dividing, timing frequency producing, 20 customers' LED states controlling are implemented in CPLD; (2)Decoding, latching data and controlling signals are implemented in CPLD by bus interface between MCU and CPLD; (3)Chip selecting principles and MCU idle mode design are completed under the consideration of low power requirement; (4)Operation by Chinese LCD menus is adopted in the Man-machine interface.Then, the detailed research and developing process is discussed: the in-system functions implementing in CPLD; hardware modules design of the main controlling board and the customer's board; testing the hardware modules one by one. And then, the software flow chart of the design of call management and telephonist's services are introduced.At the end of the thesis, the improved system's highlighted features are discussed-high reliability, security and anti-jamming, low power consumption and small size as well. Finally, the key technology and tips adopted in the project are summarized. And more, the innovation and the future work are presented.