National Instruments 370551A-01 用户手册

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页码 139
Chapter 6
NI-VXI Configuration Utility
© National Instruments Corporation
6-7
VXI/VME Shared RAM Size
This field indicates the amount of RAM (in bytes) that is shared in either 
A24 or A32 space. This determines the total shared RAM size, which is 
then divided into two equal halves that you can set up independently of one 
another. 
Note
When the Address Space field is in the default setting of A16 only, this field is 
ignored.
Shared RAM Pool
This field indicates the size of memory (in kilobytes) that is allocated at 
startup. This memory is used by the lower/upper half window when the 
Memory Select control—accessible through the Advanced popup 
field—is set to System memory
The following table indicates how the Shared RAM Pool relates to the 
VXI Shared RAM Size depending on the setting of the Memory Select 
control for the upper and lower half windows.
The shared RAM pool is used by 
VXImemAlloc()
 function calls. For 
information on the 
VXImemAlloc()
 function, refer to the NI-VXI User 
Manual
 and the NI-VXI Programmer Reference Manual.
Memory Range
Default Value
0 to 65,535 KB
0 KB
Lower Half
Window
Upper Half
Window
Shared RAM Pool
(Window)
System memory
System memory
Equal to VXI/VME
Shared RAM Size
System memory
Onboard memory
Half the VXI/VME
Shared RAM Size
Onboard memory
System memory
Half the VXI/VME
Shared RAM Size
Onboard memory
Onboard memory
0