Processor embedded in an embedded system

Processor is the "heart" of the embedded system and a very important part of the embedded system.
The 2 essential parts of the processor are:
1. Control Unit(CU) : This part helps to fetch instructions from memory.

2. Execution Unit(EU) : This part will have units(ex.ALU), that will implement data transfer, data conversion operations from one part to another.

so a processor runs the fetch and execute cycles(similar to heart pump-in and pump out of blood).

There are different types of processors
1. GPP(General Purpose Processor), ex- microprocessor

2. ASIP(Application Specific Instruction-set Processor), ex - microcontroller

3. Single purpose processor , ex - pixel processor, encrypt/decryption engine

4. GPP or ASIP integrated into a VLSI circuit or FPGA core integrated with a VLSI chip.

5.ASSP (Apllication Specific System Processor)

When we build a system the following considerations about processor has to be in our mind :

- Instruction set (Arithmetic instruction format, Conditional Branch and Immediate format, Unconditional Jump format, Input and Output instruction format).

- Maximum bits in an operand ( 8-bit,16-bit etc ).

- Clock frequency(Hz).

- Ability of the processor to solve complex algorithms.