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AS Comp - Data Flow
AS Comp
Question | Answer |
---|---|
What is a Bus? | A pathway for sending specific data. |
What is the Control Bus? | A bus used by the Control Unit to send commands to other units. |
What is the Address Bus? | Carries the address of where the data is going |
What is the Data Bus? | Carries the data from one register to another |
What does the Program Counter do? | Contains the address of the next instruction for the processor. The counter is incremented to find the next instruction. This is altered when an interrupt comes in. |
What does the MAR do? | Memory Address Register - It is where the instruction from the PC is stored for use by the CPU. |
What does the MDR do? | Memory Data Register - It finds the instruction from the address in the MAR and holds the instruction that the MAR has the address for. |
What does the CIR do? | Current Instruction Register - Takes the instruction from the MDR. Then splits up the command and sends parts to be decoded. It also holds the address of the data used in the instruction. |
What is a LAN? | Local Area Network - A group of computers connected by wireless communications within a small vicinity. |
What is a WAN? | Wide Area Network - A lot of computers linked together over a large range. Usually used in Universities and large companies. |
What is Serial Transmission? | Sending the data one bit at a time. |
What is Simplex Transmission? | Sending the data in one direction e.g. mouse to computer. |
What is full duplex transmission? | When data can be sent in both directions. |
What is half duplex transmission? | When data can be sent in both directions but not at the same time. |
What is echoing? | When data is sent and then sent back. The data will be continue to be sent until data received is the same as the data sent. |
What is CheckSum? | The data is added up and a checksum byte is created. This is then also done on the receiving side to make sure the data is correct. |
What is a Parity check? | The eighth bit of a byte is created by adding together the other bits. This is then calculated on the other side to check if the data is corrupted. |
What is a Protocol? | A set of instructions that govern data flow. |