Abstract：Programmable logic devices (FPGA) is developed rapidly in recent years, the new programmable flexible programmable logic can be easily realize high speed digital signal processing. It breaks through the parallel processing, water series, repeated programmable ability, thus effectively on the use of resources, and efficient hardware description language VHDL digital system design, so as to provide a great convenience.
This paper is based on the principle and method to design an electric clock system, aimed at through the function of the system, which reflects the FPGA in data processing applications. System based on VHDL language program, modular design method. System design includes 9 subroutine module, respectively is: frequency module, 60 into mould, 24 into mould, alarm module, regular module, 60BCD modules, 24BCD modules, 7 yards display module, scanning module. Each subroutine through simulation, and with EDA simulation diagram, the final module will assemble as a whole——electric clock. The frequency clock signal output module, then the system realized by 60 seconds count, 60 minutes count and 24 hours count, then realized by converting BCD to display the time for seven display. In order to save the current consumption, using scanning module that six display turns. The electric clock still has alarm function and timing function.
Key words: FPGA；digital electronic system design；VHDL；electronic clock
