# Down the Stack 

In this Session you will learn more about Rust's split crate model that includes
* the Board Support Crate
* an implementation of the Hardware Abstraction Layer
* the Peripheral Access Crate

This session consists of lectures and two blocks of exercises:
* BSC Exercise: Implementing further features in a basic BSC
* PAC Exercise: Generating a PAC from an SVD file and writing into registers using the the generated PAC.