SLR 1 (Components of a CPU) Flashcards
What does the PC do?
Holds the address of the next instruction to be executed
What does Accumulator do
Stores the results of calculations
What does the MAR do
Holds the address of the location that is to be read from/written to
What does MDR do
Temporarily stores the data instructions that has been read or data that has to be written
What does CIR do
Hold the current instruction being executed, divided up into operand and opcode
What is Data Bus
(2 way bus) used for transporting data and instructions between components
What is Control Bus
(2 way bus) used to transmit control signals between internal and external components. It also coordinates the use of address and data buses and provide information between system components
Examples of control signals
Bus request: shows that a device is requesting the use of the data bus
Bus grant: shows that the CPU has granted access to the data bus
Memory write: data is written into the addressed location using this bus
Memory read: data is read from a specific location to be placed onto the data bus,
Interrupt request: shows that a device is requesting access to the CPU
Clock: used to synchronise operations
Address bus
