Figure 13.47 Pcmcia Space Allocation - Hitachi SH7751 Hardware Manual

Virtual
address space
Common
memory 1
Common
Card 1
memory 2
on CS5
Attribute memory
I/O space 1
I/O space 2
Card 2
on CS6
The page size can be 1 kB, 4 kB, 64 kB, or 1 MB.
Example of PCMCIA interface mapping
I/O Card Interface Timing: Figures 13.48 and 13.49 show the timing for the PCMCIA I/O card
interface.
When an I/O card interface access is made to a PCMCIA card, dynamic sizing of the I/O bus
width is possible using the
during a word-size I/O bus cycle, the I/O port is recognized as being 8 bits in width. In this case, a
data access for only 8 bits is performed in the I/O bus cycle being executed, followed
automatically by a data access for the remaining 8 bits. Dynamic bus sizing is also performed in
the case of byte-size access to address 2n + 1.
Figure 13.50 shows the basic timing for dynamic bus sizing.
Common memory
(64 MB)
Access
by CS5 wait
controller
Access
by CS6 wait
controller
Attribute memory
(64 MB)
.
.
.
I/O space
(64 MB)
.
.
.

Figure 13.47 PCMCIA Space Allocation


pin. When a 16-bit bus width is set, if the
Virtual
address space
1 kB IO 1
page
IO 2
1 kB
Different virtual pages
page
mapped to the same
physical page
Example of I/O spaces with different cycle times
(less than 1 kB)
Rev. 3.0, 04/02, page 429 of 1064
External I/O
addresses
IO 1
IO 2

signal is high