I/O Bus:
- Components: The I/O bus consists of different types of lines:
- Data lines: These carry the actual information being transferred between the processor and peripheral devices.
- Address lines: They indicate where the data should go or come from in the memory or peripheral devices.
- Control lines: These manage the flow of data and control the operations of the peripherals.
- Communication Link: Think of the I/O bus as a highway connecting the processor (like the brain of the computer) and various peripheral devices (like printers, keyboards, etc.).
- Examples of Devices: The I/O bus connects the processor to different peripherals such as magnetic tape, magnetic disk drives, printers, and terminals.
- Connection: The I/O bus from the processor is connected to the interfaces of all the peripheral devices, acting as the communication bridge between them.
I/O Commands:
When the processor wants to communicate with a peripheral device through the I/O bus, it sends commands. These commands help in managing the communication and operations with the peripherals.
- Control Command: This command tells the peripheral to start or stop a particular operation. For example, telling a printer to start printing.
- Status Command: With this command, the processor can check various statuses of the peripheral and its interface, like whether it’s ready for data transfer or if there’s an error.
- Output Data Command: When the processor needs to send data to a peripheral, it uses this command to push data onto the bus, so the peripheral can receive it.
- Input Data Command: Conversely, when the processor wants to receive data from a peripheral, it uses this command. The peripheral sends the data onto the bus, and the processor reads it from there.
Simplified Explanation:
Imagine the I/O bus as a road system connecting the computer’s brain (processor) to different buildings (peripherals) like printers, keyboards, etc. The processor communicates with these buildings using different types of commands:
- Control Command: Start or stop a building’s operation.
- Status Command: Check if a building is ready or has encountered any problems.
- Output Data Command: Send something from the processor to a building.
- Input Data Command: Receive something from a building to the processor.