Filter
Top Products
Register Descriptions Chapter 4
VXI-MXI User Manual 4-16 © National Instruments Corporation
The A16 Window Map Register has the following format when the CMODE bit is set:
R/W
7 65432
1
A16LOW7 A16LOW6 A16LOW5 A16LOW4 A16LOW3 A16LOW2
A16LOW1
A16LOW0
0
15 14 13 12 11 10 9 8
R/W
A16HIGH7 A16HIGH6 A16HIGH5 A16HIGH4 A16HIGH3 A16HIGH2
A16HIGH1
A16HIGH0
Bit Mnemonic Description
15-8r/w A16HIGH[7-0] A16 Window Upper Bound Bits
These bits define the upper limit of the range of MXIbus A16
addresses that map into the VXIbus.
7-0r/w A16LOW[7-0] A16 Window Lower Bound Bits
These bits define the lower limit of the range of MXIbus A16
addresses that map into the VXIbus.
This register defines the range of MXIbus A16 addresses that map into the VXIbus where that
range is:
A16HIGH > range A16LOW
The VXIbus A16 addresses mapped out of the VXI-MXI are the inverse of this range, that is,
MXIbus A16 addresses greater than or equal to the A16HIGH value or less than the A16LOW
value.
To map a consecutive range of VXIbus A16 addresses out of the VXI-MXI, the lower bound of
the range must be placed in the A16HIGH field and the upper bound in the A16LOW field. In
this case, the range of VXIbus A16 addresses mapped out of the VXI-MXI is:
A16LOW > range A16HIGH
The MXIbus A16 addresses mapped into the VXIbus are the inverse of this range, that is,
VXIbus A16 addresses greater than or equal to the A16LOW value or less than the A16HIGH
value.
The window is disabled whenever A16HIGH = A16LOW = 0. All VXIbus A16 addresses are
mapped out to the MXIbus when:
FF (hex) (A16HIGH = A16LOW) 80 (hex)
All MXIbus A16 addresses are mapped into the VXIbus when:
7F (hex) (A16HIGH = A16LOW) > 0