Processor

Program Flow and data path Control Unit (CU) —includes a fetch unit for fetching
instructions from the memory Execution Unit (EU) — includes circuits for arithmetic and
logical unit(ALU), and for instructions for a program control task, say, data transfer
instructions, halt, interrupt or jump to another set of instructions or call to another routine or
sleep or reset. The processor used in embedded systems can be of three types:
ப்‌ Micro-Controllers

Microcontrollers comprise the main elements of a small computer system on a single
chip. They contain the memory, and IO as well as the CPU one the same chip. This

considerably reduces the size, making them ideal for small embedded systems, but means

that there are compromises in terms of performance and flexibility.