ALU

• Responsible for arithmetic calculations

Buses

Address bus

<aside> 💡 Used to transmit the address in the RAM of the next line of program code to be fetched. Used to transmit the address of a RAM location or input/output port where data is to be stored or loaded

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Data bus

<aside> 💡 Used to transfer program code between RAM memory and the processor. Used to transfer data between the processor and RAM memory or input/output ports

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Control bus

<aside> 💡 Used to send control signals from the processor to the RAM memory or input/output ports to initiate data transfer. Carries interrupt signals to the processor to indicate that hardware/software requires attention.

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Registers

<aside> 💡 Small blocks of memory used for any storage needed by instructions currently being executed

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1. General purpose registers - can be used by the developer to store any values they wish
2. Special purpose registers - have a more specific purpose

Examples of special purpose registers

1. Program Counter - used to store the next instruction to be executed
2. Memory Address Register - used to store the memory address where the next instruction is located
3. Memory Data Register - used to store the data at the memory address that is to be executed