## Programmed Input/Output (PIO)

Basically, PIO means that the processor is responsible to write a byte/word at a time to one I/O address at a time to communicate a block of data. Note that for x86, I/O space means something different than most other arch's as x86 has seperate I/O and memory spaces -- addressed by different instructions out/in vs store/load (okay, it's **mov** in x86 parlance, but if you know that, you already should know what I'm talking about). Think of PIO as writing to or reading from one end of a FIFO while the target reads/writes to the other end. 



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 [[CategoryGlossary|CategoryGlossary]]