National Instruments VXI-MXI User Manual page 81

Chapter 4
12-11r/w 1
10-8r/w A32SIZE[2-0]
7-0r/w A32BASE[7-0]
A32 Window Example:
A32BASE
any value
C8
3E
49
9A
21
75
19
FF
FF
FF
FF
FF
FF
FF
FF
© National Instruments Corporation
A32EN A32DIR
0
1
Reserved Bits
These bits are reserved and read back as ones. Write a zero when
writing to these bits.
A32 Window Size Bits
This 3-bit number specifies the number of significant address bits
in the A32BASE field that are compared when determining if an
address is in the A32 window. The number of A32 addresses in
the window is 16,777,216 * 2
A32SIZE[2-0]. The minimum size of an A32 window is 32 MB,
and the maximum size is 4 GB.
A32 Window Base Address Bits
These bits, in conjunction with the A32SIZE bits, define the base
address of the A32 window for the VXI-MXI. The A32SIZE bits
indicate the number of A32BASE bits that are most significant.
A32BASE7 is the most significant and A32BASE0 is the least.
The A32BASE bits that are not significant can be replaced with
zeros to provide the base address of the A32 window.
A32SIZE A32 Addresses in Window
0 00000000 to FFFFFFFF
1 80000000 to FFFFFFFF
2 00000000 to 3FFFFFFF
3 40000000 to 5FFFFFFF
4 90000000 to 9FFFFFFF
5 20000000 to 27FFFFFF
6 74000000 to 77FFFFFF
7 18000000 to 19FFFFFF
0 00000000 to FFFFFFFF
1 80000000 to FFFFFFFF
2 C0000000 to FFFFFFFF
3 E0000000 to FFFFFFFF
4 F0000000 to FFFFFFFF
5 F8000000 to FFFFFFFF
6 FC000000 to FFFFFFFF
7 FE000000 to FFFFFFFF
4-23
Window Applies to
X Disabled
VXI cycles to MXI cycles
0
1 MXI cycles to VXI cycles
8-i
where i is the value of
Register Descriptions
VXI-MXI User Manual