1.1.1- Processor Components Flashcards
What is the function of the control unit ?
→ Coordinates all activities of the CPU
→ Directs flow of data between CPU and other devices
What is a bus?
Parallel wires that connect 2 or move components together
What does PC do?
Program counters holds address of the next instruction.
MAR
memory address register holds address of the memory location from which data or instructions is fetched or written
Sends to main memory,
MDR
memory data register
Temporarily stores data which is read from or written to memory
AKA buffer register
CIR
Current instruction register
Holds the current instruction being executed
ALU
Arithmetic logic unit
Performs arithmetic and logical operations on data
ACCUMULATOR
General purpose register
Stores temporary data while instructions or calculations are being carried out.
Stores temporary ALU calculations
Acts as a buffer
Temporary storage for data being processed during calculations
ADDRESS BUS
Carries memory addresses that identify where the data is being read from or written to
Sends address to memory
DATA BUS
Carries binary 1’s and 0’s that make up actual information being transmitted around the computer
Bidirectional
CONTROL BUS
Carries command and control signals to and from every other component of the CPU
controls signals sent
Bi directional
What does bus grant Indicate?
Indicates the CPU has granted access to the data bus
What does memory write do?
Causes the data on data bus to be written into the addressed location
What does memory read do?
Causes the data from the addressed location to be placed onto the data bus
What does the interrupt request control signal indicate?
Indicates that a devise is requesting access to the CPU
