I wanted to test some more advanced programming (i.e. sequential circuits) of the CPLD, sequential circuits need their inputs to have stable transitions, i.e they need to be debounced.
Sequential circuits (synchronous and asynchronous) need debounced inputs, here is a good guide on how and why should one debouce an manual input.
I used the RS Latch method in Figure 1 of the document above, but since I used standard TTL 74 series, inputs floating are considered as "ONE", so I can do without the input resistors. I also tried out the RC filter approach the circuit is depicted on top.
This is a picture of CPLD, the clock circuit (with 2 inputs) and the 4 push button inputs and 4 LED outputs.
2 weeks ago