14. Input/Output Address Space

• Pentium x86 provides 64 KB of I/O address space.

• Can be used for 8-, 16-, and 32-bit I/O ports.

• Combination cannot exceed the total I/O address space, can have either

  • 64 K 8-bit ports

  • 32 K 16-bit ports

  • 16 K 32-bit ports

  • A combination of these for a total of 64 KB.

• I/O instructions do not go through memory segmentation or paging.

• I/O address refers to the physical I/O address.