The NDIS library provides a set of I/O functions that a miniport NIC driver calls to access I/O ports. These calls provide a standard portable interface that supports the various operating environments for NDIS drivers. Functions are provided for mapping ports, for claiming I/O resources and for reading from and writing to the mapped and unmapped I/O ports.
| Function | Definition |
| NdisMRegisterIoPortRange | Sets up access to I/O ports for using NdisRawReadPortXxx and NdisRawWritePortXxx. |
| NdisMDeregisterIoPortRange | Removes access to I/O ports previously registered with NdisMRegisterIoPortRange. |
| NdisMMapIoSpace | Maps a range of device memory for subsequent PIO operations. |
| NdisMUnmapIoSpace | Releases a region mapped by a call to NdisMMapIoSpace. |
| NdisImmediateReadSharedMemory | Reads a single buffer of data from a shared memory address before the driver has called NdisMMapIoSpace. |
| NdisImmediateWriteSharedMemory | Writes a single buffer of data to a shared memory address before the driver has called NdisMMapIoSpace. |
| NdisRawReadPortXxx | Read a single piece of data from an I/O port. Specific functions include:
NdisRawReadPortUchar |
| NdisRawReadPortBufferXxx | Read a buffer of data a piece at a time from an I/O port. Specific functions include:
NdisRawReadPortBufferUchar |
| NdisRawWritePortXxx | Writes a single piece of data to an I/O port. Specific functions include:
NdisRawWritePortUchar |
| NdisRawWritePortBufferXxx | Writes a buffer of data to I/O port. Specific functions include:
NdisRawWritePortBufferUchar |
| NdisImmediateReadPortXxx | Reads a piece of data from an I/O port before the driver has mapped the port by calling NdisMRegisterIoPortRange. Specific functions include:
NdisImmediateReadPortUchar |
| NdisImmediateWritePortXxx | Writes a piece of data from an I/O port before the driver has mapped the port by calling NdisMRegisterIoPortRange. Specific functions include:
NdisImmediateWritePortUchar |