There are two styles of reset that can be applied to a synchronous design (i.e. a design with state elements); these are synchronous and asynchronous. The examples given in the lab and in the lectures are in fact all asynchronous. There has been much debate about which of these is the best to use - the paper below discusses this potentially confusing topic and offers some clarity.
- Synchronous Resets? Asynchronous Resets? I am so confused! How will I ever know which to use?, C.E. Cummings and D. Mills, Sunburst Design Inc.