Computer Architecture Processor Structure Processor Function Look Inside

The control unit of the processor reads an instruction to load data from a certain memory location. This instruction will be latched into the instruction register. This engages the read line and receives contents of memory into the data bus. Then this data is latched into one of the registers awaiting further instruction.

The next instruction (to add data from a different memory location) is read from the instruction decoder and latched onto the instruction register. This engages the read line and receives contents of memory onto the data bus, latching it into the other register. Then the ALU is set for addition and processes the data from the registers, adding one quantity to the other.

The result is latched onto a third register. A final instruction is then needed to transfer the data from the register, engage the write line, and send the data through the data bus for storage in a certain memory location.

Arithmetic Logic Unit: Performs calculations with data from registers. Typically can be set to add, subtract, multiply and compare data.

Control Unit: Instruction decoder and register. Extracts instructions from memory and sends them to the registers and ALU for execution.

Registers: Flip flops that latch the data from the ALU or data bus.

Address bus: Sends an address to memory.

Data bus: Sends data to memory and receives data from memory.

Read and Write lines: Tell whether to load data from a particular memory location or write data to that memory location.