Often the lack of good understanding of the fundamental concepts is the reason for difficulty later. Every Embedded System is an always ON system that responds to events around them. Meeting deadlines and achieving real time behavior depends heavily on interrupts and its effective management. And understanding how RTOSwork shall help in effectively putting together an Embedded System product. This is a thorough course from a seasoned expert. Examples are with 8051 Assembly Language. It is a simple microcontroller but yet packed with features. Once you are comfortable with 8051, you can directly transition to processors like ARM.