User manual

Chapter 6 System Configuration
VXI-MXI-2 User Manual 6-4 © National Instruments Corporation
zeros gives the actual base address of the window. In other words, the
Base and Size define a range of addresses that are in the window. A
Direction bit is also included to indicate whether the defined range of
addresses are mapped into or out of the VXIbus mainframe.
Table 6-1 shows which bits are compared for each Size setting and the
resulting address range in hex if Base is set to 0 and hex 55. Figure 6-3
further illustrates the number of bits of the Base that are compared for
each Size value. Notice that if Size = 0, no bits are compared.
Figure 6-4 shows the address range allocation for different Size values.
Table 6-1. Base and Size Combinations
Size Base7 Base6 Base5 Base4 Base3 Base2 Base1 Base0
Range
for 0
Range
for 55
7 * * * * * * * 0 to 1 54 to 55
6 * * * * * * 0 to 3 54 to 57
5 * * * * * 0 to 7 50 to 57
4 * * * * 0 to F 50 to 5F
3 * * * 0 to 1F 40 to 5F
2 * * 0 to 3F 40 to 7F
1 * 0 to 7F 00 to 7F
0 0 to FF 00 to FF
Base7 Base6 Base5 Base4 Base3 Base2 Base1 Base0
Size = 1
Size = 2
Size = 3
Size = 4
Size = 5
Size = 6
Size = 7
Figure 6-3. Base and Size Combinations