National Instruments VXI-MXI User Manual page 69

Chapter 4
12-11r/w 1
10-8r/w LASIZE[2-0]
7-0r/w LABASE[7-0]
Logical Address Window Example:
LABASE
any value
00
08
18
3F
55
88
CC
AA
AA
AA
AA
AA
AA
AA
AA
© National Instruments Corporation
LAEN LADIR
0
1
Reserved Bits
These bits are reserved and read back as ones. Write a zero when
writing to these bits.
Logical Address Window Size Bits
This 3-bit number specifies the number of significant address bits
in the LABASE field that are compared when determining if an
address is in the logical address window. The number of logical
addresses in the window is 2
[2-0]. Because i can range from 0 to 7, the minimum size of a
logical address window is 2, and the maximum size is 256.
Logical Address Window Base Address Bits
These bits, in conjunction with the LASIZE bits, define the base
address of the Logical Address window for the VXI-MXI. The
LASIZE bits indicate the number of LABASE bits that are most
significant. LABASE7 is the most significant, and LABASE0 is
the least. The LABASE bits that are not significant can be
replaced with zeros to provide the base address of the logical
address window.
LASIZE Logical Addresses in Window
0
1
2
3
4
5
6
7
0
1
2
3
4
5
6
7
4-11
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 LASIZE
00 to FF
00 to 7F
00 to 3F
00 to 1F
30 to 3F
50 to 57
88 to 8B
CC to CD
00 to FF
80 to FF
80 to BF
A0 to BF
A0 to AF
A8 to AF
A8 to AB
AA to AB
Register Descriptions
VXI-MXI User Manual