Specifications

12 Issue 5, August 1994 Acorn Enhanced Expansion Card
Acorn Enhanced Expansion Card
Figure 7: Stretched expansion card read cycle
REF8M
IORQ
IOGT
PS
PRE
RBE
BL
BD[0:15]
LA[2:15]
PR/W
CLK8
Expansion card accesses
The following diagrams detail the four possible types of
IOC expansion card access (slow, medium, fast, and
synchronous). In each diagram REF8M is shown, but
this is only for reference. The phase relationship of
REF8M and CLK8 is NOT guaranteed.
Figure 8: Slow cycle read
PS
PRE
BD[0:15]
LA[2:15]
PR/W
|Z
CLK8
REF8M