Addressing and Managing I/O
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Addressing an I/O Device
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Dedicated CPU I/O instructions.
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Memory-mapped I/O
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Portions of the address space are assigned for I/O devices.
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Loads and stores to these addresses cause data to be transferred.
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Managing an I/O Operation
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Polling - periodically check status bits
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Interrupt-driven I/O - interrupt generated after each I/O event
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Direct memory access (DMA) - special controller that transfers
data between an I/O device and memory independent of the processor
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