Protocol Chips Design for PLC Back to Back Bus Based on CPLD
TAN Ai-guo1, JU Chang-jiang2 (1.School of Optical-Electrical and Computer Engineering, University of Shanghai for Science and Technology,Shanghai 200093,China;2.Shanghai Electrical Apparatus Research Institute(Group)Co.,Ltd.,Shanghai 200063,China) Abstract:A couple of Protocol chips designed for programmable logical controller (PLC) back to back bus based on CPLD is present. Protocol chips can recognize periodical data and nonperiodic data of PLC back to back bus. The detail of how to design state machine, frame controller and FIFO controller in Verilog HDL language is described in the article. The stable work performance of protocol chips in 25MHz proved that the design is feasible. Key words:back to back bus;protocol chips;complex programmable logic device(CPLD);programmable logic controller(PLC) |