Digital clock design

This paper introduces the design requirements and methods of digital clock, including basic requirements and extended requirements, as well as the design methods and descriptions of input and output ports.

basic requirement

We can use the existing hardware system to design a control circuit that can display minutes and seconds at least. Minutes and seconds are indicated by two digital tubes, and have time adjustment and reset functions.

Extended requirements

It can display hours (two digital tubes) and adjust hours at the same time; With alarm clock timing function.

design method

Using modular description method, it can be divided into frequency division module, time sequence control module, digital display module, reset module and so on. Each module can be edited into an independent HDL file or GDF file, and can also be used as a process module in HDL programs. Finally, the system is simulated and verified, and on this basis, it is downloaded to the hardware for field testing.

I/O port description

Input signals-clock signal clk, reset signal clr, time setting key set, time increasing key tup and time decreasing key tdown；; Output signal-scanning seven-segment digital tube with segment selection output led[7..0] and position selection output ctrlbit[3..0].