1.1.1 Structure and function of the processor Flashcards
What does the ALU do?
Completes all mathematical and boolean operations
What is the control unit?
Component that directs operations in the CPU
What are registers?
Small memory cells that operate at high speeds
What does the PC do?
Holds the address of the next instruction to be fetched
Where are the arithmetic and logic results stored?
Accumulator
What does the MAR do?
Holds the address of the location that’s to be written to or from
What does the MDR do?
Temporarily holds the data that had just been read from or the data that needs to be written
What does the CIR do?
Holds the current instruction divided into opcode and operand
What is opcode?
Is used to determine the type of instruction and what hardware to use to execute it
What is the operand?
The address of where the operation is performed
What occurs in the fetch phase?
- The address from the PC is copied into the MAR
- The data held at that memory address in the RAM is copied into the MDR
- The PC is incremented by one
- The value in the MDR is copied into the CIR
What occurs in the decode phase?
Contents of CIR are split into operand and opcode
What occurs during the execute phase?
The opcode is executed on the data
What is pipelining?
Process of overlapping the fetch, decode, and execute stages so all three are operating at the same time
What is Harvard architecture?
Architecture in which there are 2 separate memory and buses for data and instructions
