user manual

3. ADDRESSING
The MPA-100 occupies a continuous 8 byte block of I/O addresses. For example, if the
base address is set to 300H, then the MPA-100 will occupy address locations 300H-307H. The
base address of the MPA-100 may be set to any of the first 64 Kbytes (0 - FFFFH) of available
I/O address space through the settings of dip switches SW1 and SW2. SW1 allows the user to
select the higher address signals A15 - A8. SW2 allows the user to select the lower address
signals A7 - A3. The sixth position of SW2 is not used and can be ignored. Figure 2 shows some
examples of different base addresses.
Figure 2 Address switch selection examples
ON
ON
ON
ON
1
1
2
2
3
3
4
4
5
5
6
6
7
7
8
8
1
1
2
2
3
3
4
4
5
5
6
6
Base Address = 300H
Base Address = 3F8H
SW1
SW2
SW1
SW2
A15
A13
A12
A11
A10
A9
A8
A7
A6
A5
A4 A3
NOT USED
A15
A14 A13 A12
A11
A10
A9
A8
A7
A6
A5
A4 A3
NOT USED
A14
MPA-100 User's Manual 3-1