Register Descriptions
Chapter 4
VXI-MXI User Manual
4-24
© National Instruments Corporation
The A32 Window Map Register has the following format when the CMODE bit is set:
R/W
7
6
5
4
3
2
1
A32LOW7
A32LOW6
A32LOW5
A32LOW4
A32LOW3 A32LOW2 A32LOW1
A32LOW0
0
15
14
13
12
11
10
9
8
R/W
A32HIGH7 A32HIGH6 A32HIGH5 A32HIGH4 A32HIGH3 A32HIGH2 A32HIGH1 A32HIGH0
Bit
Mnemonic
Description
15-8r/w A32HIGH[7-0]
A32 Window Upper Bound
These bits define the upper limit of the range of MXIbus A32
addresses that map into the VXIbus.
7-0r/w
A32LOW[7-0]
A32 Window Lower Bound
These bits define the lower limit of the range of MXIbus A32
addresses that map into the VXIbus.
This register defines the range of MXIbus A32 addresses that map into the VXIbus where that
range is:
A32HIGH > range A32LOW
The VXIbus A32 addresses mapped out of the VXI-MXI are the inverse of this range, that is,
MXIbus A32 addresses greater than or equal to the A32HIGH value or less than the A32LOW
value.
To map a consecutive range of VXIbus A32 addresses out of the VXI-MXI, the lower bound of
the range must be placed in the A32HIGH field and the upper bound in the A32LOW field. In
this case, the range of VXIbus A32 addresses mapped out of the VXI-MXI is:
A32LOW > range A32HIGH
The MXIbus A32 addresses mapped into the VXIbus are the inverse of this range, that is,
VXIbus A32 addresses greater than or equal to the A32LOW value or less than the A32HIGH
value.
The window is disabled whenever A32HIGH = A32LOW = 0. All VXIbus A32 addresses are
mapped out to the MXIbus when:
FF (hex) (A32HIGH = A32LOW) 80 (hex)
All MXIbus A32 addresses are mapped into the VXIbus when:
7F (hex) (A32HIGH = A32LOW) > 0
