C Pointers, Memory, and Low-Level Concepts

Explain what `volatile` signals to the compiler and identify scenarios where its omission causes bugs (e.g., hardware registers, ISR-shared variables).

Analyze code combining `const` and `volatile` to explain why both can apply to the same variable (e.g., a read-only hardware status register).

Explain what a double pointer (pointer to a pointer) stores and trace multi-level dereferencing in code.

Use `malloc`, `calloc`, `realloc`, and `free` correctly and explain the differences between them.

Define and use bit-fields in structures to model hardware register layouts.