1.1 System Arichitecture

1.1 System Arichitecture

1. FDE cycle

   • DECODE
     • The instruction in the MDR is decoded by the CU. The CU may then prepare for the next step, e.g by loading values into the MAR or MDR
   • FETCH
     • 1) Copy memory address from the program counter to the MAR
       • 2) Copy the instructions stored in the MAR address to the MDR
         • Increment (increase) the program counter to point to the address of the next instruction, ready for the next cycle
   • EXECUTE
     • The instruction is performed. this could be: load data from memory, write data to memory. do a calculation or logic operation (using the ALU), change the address in the PC, or halt the program

2. The purpose of the CPU

   • The CPU is the brain of the computer system, It processes all of the data and instructions that make the system work.

3. Embedded systems

   • A computer systems built into a device (usually for a specific purpose

4. Characteristics

   • Cashe
     • Cashe is a very fast form of memory that stores regularly used data for the CPU to access it quicker next time its needed.
   • Clockspeed
     • Number of instructions that can be carried out in a second (Hz) - These days in Ghz (Billion)
   • number of cores
     • How many individual processors (cores) are on a chip. The more cores, the more instructions can be done simultaneously.