Table of Contents
Advertisement
Chapter 4
12-11r/w 1
10-8r/w
A24SIZE[2-0]
7-0r/w
A24BASE[7-0]
A24 Window Example:
A24BASE
any value
4E
A7
35
6C
81
B4
02
00
00
00
00
00
00
00
00
© National Instruments Corporation
A24EN
A24DIR
0
1
Reserved Bits
These bits are reserved and read back as ones. Write a zero when
writing to these bits.
A24 Window Size Bits
This 3-bit number specifies the number of significant address bits
in the A24BASE field that are compared when determining if an
address is in the A24 window. The number of A24 addresses in
the window is 65536 * 2
The minimum size of an A24 window is 128 KB, and the
maximum size is 16 MB.
A24 Window Base Address Bits
These bits, in conjunction with the A24SIZE bits, define the base
address of the A24 window for the VXI-MXI. The A24SIZE bits
indicate the number of A24BASE bits that are most significant.
A24BASE7 is the most significant and A24BASE0 is the least.
The A24BASE bits that are not significant can be replaced with
zeros to provide the base address of the A24 window.
A24SIZE
A24 Addresses in Window
0
000000 to FFFFFF
1
000000 to 7FFFFF
2
800000 to BFFFFF
3
200000 to 3FFFFF
4
600000 to 6FFFFF
5
800000 to 87FFFF
6
B40000 to B7FFFF
7
020000 to 03FFFF
0
000000 to FFFFFF
1
000000 to 7FFFFF
2
000000 to 3FFFFF
3
000000 to 1FFFFF
4
000000 to 0FFFFF
5
000000 to 07FFFF
6
000000 to 03FFFF
7
000000 to 01FFFF
4-19
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 A24SIZE[2-0].
Register Descriptions
VXI-MXI User Manual
Advertisement
Table of Contents
