There are many ways to display text on an embedded device, but not all of them may fit your HW design. This post will expose most of your options and give you a good intuition about what you need to know in order to create great graphics software. Even if you only do hardware, this will still be of interest to you, since you will get a better understanding of what the architecture of your system needs to be to be able to display text with a certain quality.
Most microcontrollers now include the options to select the GPIO speed for a certain pin inside a port. Many will announce this feature as GPIO max current control or slew-rate, but in the end they are talking about the same thing. First of all, why would you ever need to control GPIO current? Wouldn’t it be great to leave this at the maximum level at all times? Well, it is usually not that simple, and more so as integrated circuits get larger clock frequencies.