FPGA Concepts: Flipflops

How do you program an FPGA? What does the concepts even mean? How do FPGA programming languages differ from software programming languages? These are the questions we'll tackle in this series.

The third part deals with stateful logic design in HDL (hardware description languages). We go through what is a flip flop, how it's used. We demonstrate this using a frequency divider.

I want to thank all of my Patreaon supporters, and especially my BBC Micro level supporters:
Yehuda T. Deutsch

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Bill of materials:
FPGA board is out of production. A similar one is at https://www.aliexpress.com/item/10050...
Scope is the Hantek DSO2C10. It's about the cheapest scope you can buy with buttons and knobs (which I find crucial for sane interaction), and does the job very well.

Table of contents:
00:00 - Previous videos recap
00:34 - SR latch
02:13 - D latch
02:59 - Edge trigger
04:17 - D Flilpflop
05:20 - Blink top module
05:57 - Defining the constraints, reading the schematics
09:13 - LED constraints
11:26 - Loading the design
12:35 - Frequency divider
15:22 - Procedural assignment visibility
16:41 - Wrong frequency
17:45 - Frequency is still off
19:53 - Resources used by the design
23:13 - Adding async reset
24:49 - Reducing resources