Port IO: Difference between revisions

The x86 architecture separates the address space in two programmatically distinct groups: memory and ports. In ancient history, memory was used as the storage of data where reads and writes would not have side-effects, and ports were used to control external hardware, which needed different timings to work. Which is also why accessing ports is so much slower than accessing memory. Many other common architectures have a unified space, where devices run at the same speed as memory, or where the address space is divided into blocks with separately configurable properties.

 

 

== How to access ports ==