Chapter 4 Register Descriptions
© National Instruments Corporation 4-15 VXI-MXI User Manual
A16EN A16DIR Window Applies to
0 X Disabled
10
VXI cycles to MXI cycles
1 MXI cycles to VXI cycles
12-11r/w 1 Reserved Bits
These bits are reserved and read back as ones. Write a zero when
writing to these bits.
10-8r/w A16SIZE[2-0] A16 Window Size Bits
This 3-bit number specifies the number of significant address bits
in the A16BASE field that are compared when determining if an
address is in the A16 window. The number of A16 addresses in
the window is 256 * 28-i where i is the value of A16SIZE[2-0].
The minimum size of an A16 window is 512 B and the maximum
size is 48 KB (A16SIZE = 0).
7-0r/w A16BASE[7-0] A16 Window Base Address Bits
These bits, in conjunction with the A16SIZE bits, define the base
address of the A16 window for the VXI-MXI. The A16SIZE bits
indicate the number of A16BASE bits that are most significant.
A16BASE7 is the most significant and A16BASE0 is the least.
The A16BASE bits that are not significant can be replaced with
zeros to provide the base address of the A16 window.
A16 Window Example:
A16BASE A16SIZE A16 Addresses in Window
any value 0 0000 to BFFF
3F 1 0000 to 7FFF
80 2 8000 to BFFF
26 3 2000 to 3FFF
49 4 4000 to 4FFF
98 5 9800 to 9FFF
42 6 4000 to 43FF
A1 7 A000 to A1FF
55 0 0000 to BFFF
55 1 0000 to 7FFF
55 2 4000 to 7FFF
55 3 4000 to 5FFF
55 4 5000 to 5FFF
55 5 5000 to 57FF
55 6 5400 to 57FF
55 7 5400 to 55FF