So, I'm trying to design a digital 24 hour clock in Multisim that will include buttons, when pressed, will increase or decrease the figures. The problem is that I cannot figure out how to implement a button that can decrease the figures CORRECTLY.
So far, what I have did is build four of 4 bit mod 10 synchronous counters and using the previous counter's reset as a clock signal for the next counter. What this means that, in the 4-bit synchronous counter that represents the 2nd digit of minute, there will be an output, whose input is 0101 (number 10 because it is supposed to go back to 0 after 9) and it goes into reset of the counter. This output also serves as a clock pulse for the 4 bit-synchronous counter that represent the 1st digit of minute because only then, the 1st digit will increase when the 2nd digit goes from 9 back to 0.
I cannot figure out how to implement a button to decrease the figures. I tried to use an up/down counter but since the resets are given signal at some point in the sequence, it doesnt work; like, when it is at 0, it doesnt go back but just sticks at 0 (because obviously when it tries to go back, it just resets the counter).
This is my university project and I cannot fail this. I am not taking an easy path of just asking other people, I have done a lot of research and tried to think of many ways. Any help is GREATLY appreciated.
Thank you
