National Instruments NI-VXI

Chapter 3 Software Overview

SetPrivilege (window, priv)

SetPrivilege sets the VXI/VMEbus windowing hardware to access

the specified window with the specified VXI/VMEbus access privilege.

The possible privileges include Nonprivileged Data, Supervisory Data,

Nonprivileged Program, Supervisory Program, Nonprivileged

Block, and Supervisory Block access. The application must have

Owner-Access Privilege to the applicable window for this function to

execute successfully. Notice that some platforms may not support all of

the privilege states. This is reflected in the return code of the call to

SetPrivilege. Nonprivileged Data transfers must be supported

within the VXI/VME environment, and are supported on all hardware

platforms.

UnMapVXIAddress (window)

UnMapVXIAddress reallocates the window mapped using the

MapVXIAddress function. If the caller is an Owner-Privilege accessor

(only one is permitted), the window is free to be remapped. If the caller

is an Access-Only Privilege accessor, the window can be remapped

only if the caller is the last Access-Only accessor. After a call is made

to UnMapVXIAddress, the pointer obtained from MapVXIAddress is

no longer valid. You should no longer use the pointer because a

subsequent call may have changed the settings for the particular

window, or the window may no longer be accessible at all.

VXIpeek (addressptr, width, value)

VXIpeek reads a single byte, word, or longword from a particular

address obtained by MapVXIAddress. On most platforms using

C language interfaces, VXIpeek is a macro. It is recommended,

however, that you use VXIpeek instead of a direct dereference of the

pointer, as it supports portability between different platforms and

programming languages.

VXIpoke (addressptr, width, value)

VXIpoke writes a single byte, word, or longword to a particular

address obtained by MapVXIAddress. On most platforms using

C language interfaces, VXIpoke is a macro. It is recommended,

however, that you use VXIpoke instead of a direct dereference of the

pointer, as it supports portability between different platforms and

programming languages.