1.1 Systems Architecture Flashcards
Describe what happens in the Fetch stage of the Fetch-Execute Cycle.
Address Bus takes memory address from the Memory to the MAR.
Address Bus from MAR goes to the RAM to fetch data.
Data is copied from the RAM onto the Data Bus and taken to the MDR.
Instruction it then taken to the CU and sends instruction on the Control Bus to increment PC by 1.
Describe what happens in the Decode stage of the Fetch-Execute Cycle.
Data given to the CU is decoded.
CU gives instructions to different components.
Describe what happens in the Execute stage of the Fetch-Execute Cycle.
CU updates MAR with memory location for data.
Data Bus retrieves data from RAM and takes it to the MAR.
Data is taken to the ACC and transferred to the ALU to be processed.
Purpose of the Memory Address Register.
Stores location in the memory to be used by the MDR.
Holds address of data to be fetched/stored.
Purpose of the Memory Data Register.
Holds data fetched from or to be written to the memory.
Purpose of the Program Counter.
Holds the address of the next instruction.
Purpose of the Accumulator.
Holds the results of calculations.
Purpose of the Arithmetic Logic Unit.
Performs calculations.
Purpose of the Control Unit.
Decodes instructions and sends signals to control how data moves around the CPU.
Purpose of the Cache.
Provides fast access to frequently used instructions and data without the need to go to the main memory (RAM).
Define the Von Neumann Architecture.
Where both data and software that are currently being used are stored in the RAM.
Define “Embedded System”.
A computer system with a dedicated function within a larger mechanical system.
Examples of Embedded Systems.
Traffic lights
Hospital Equipment
Factory Equipment
Features of an Embedded System.
Built for a specific need.
Cannot be changed easily.
Factors the affect the performance of the CPU.
Clock speed
Cache size
Number of Cores
What is the Cache?
Small amount of high-speed random access memory built directly within the processor.
What is a Clock used for?
Used to coordinate all the computer’s components.
What is Clock Speed?
Frequency of pulses
Higher frequency means more fetch-decode-executed cycles performed per second.
State an disadvantage of a high Clock Speed.
Overclocking may cause long-term damage to the CPU as it produces more heat.
State an advantage of a high Clock Speed.
More fetch-decode-execute cycles performed per second.
State an disadvantage of a large Cache.
Processor has more data to look through for the data wanted.
More expensive to build than RAM.
State an advantage of a large Cache.
Processor takes less time waiting for instructions to be fetched.
What is a Core?
A processing unit within the CPU.
State the function of a Core.
Fetching, decoding and executing instructions.
