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| I/O Communication |
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| Techniques |
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| ä | 3
techniques are possible for I/O operation |
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| ä | Programmed
I/O |
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| ä | Does
not use interrupts: CPU has to wait for |
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| completion
of each I/O operation |
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| ä | Interrupt-driven
I/O |
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| ä | CPU
can execute code during I/O operation: it |
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| gets
interrupted when I/O operation is done. |
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| ä | Direct
Memory Access |
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| ä | A
block of data is transferred directly from/to |
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| memory
without going through CPU |
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