Xycom XVME-240 Manual page 47

XVME-560 Manual
September, 1984
On an intelligent XVME module, address
base addresses in 1K (400H) increments.
signals Al0-A13 are decoded, while Al4 and Al5 must be zero. (This implies that only
the lowest 16 of the possible 64 1K segments are used for intelligent modules.) On
non-intelligent modules, the six highest order short I/O address bits are
XVME
decoded, while the remaining lower order bits are ignored. This arrangement provides
the correct address configuration to allow each module address to begin on a 1K
boundary. Non-intelligent XVME modules allow the use of six base address jumpers
(representing bits Al0-A15), and thus, they are able to reside on any of the 64
1K
boundaries available in the short I/O address space. Intelligent XVME modules will
only allow the use of four base address jumpers (representing bits AI0-A13) which
limits their selection of 1K boundaries to one of 16 possible choices.
Figure A-l shows an abbreviated view of the short I/O memory.
Short I/O
BASE
Address Space
0
08OOH
3
4
63
Figure A-1. 64K Short I/O Address Space
A-2