Intel
®
81341 and 81342—Peripheral Bus Interface Unit
Intel
®
81341 and 81342 I/O Processors
Developer’s Manual
December 2007
714
Order Number: 315037-002US
9.2.6
Flash Memory Support
PBI peripheral bus interface supports 8-, or 16- bit Flash devices.
The PBI provides programmable wait state functionality for peripheral memory
windows.
Note:
Potentially, programmable wait state functionality could be connected to any peripheral
device that has a deterministic wait state profile. However, data valid and turn-around
times would need to fit within parameters provided by programmable wait state profiles
to support Flash devices.
Any write transactions issued to a Flash address space window must always represent a
single flash bus data cycle (
strb, strh
).
The peripheral chip enables,
PCE[1:0]#
, activate the appropriate Peripheral window
when the address falls within one of the Peripheral address ranges.
Note:
By default, bank 0 is enabled with the maximum number of Address-to-Data and
Recovery Wait states. The width of the interface can be strapped for either 8-bit wide
Flash or 16-bit wide flash. Thus,
PCE0#
is the Peripheral Bus chip enable to be used for
booting purposes.
illustrates how two 8-bit Flash devices would interface with an
Intel XScale
®
processor through the PBI Interface.
Figure 108. Sixty-Four Mbyte Flash Memory System
A[24:00]
POE#
PWE#
PCE0#
PCE1#
Intel® 81348
I/O Processor
A[24:0]
OE#
WE#
DQ[7:0]
CE#
Intel®
28F256J3
256 Mbit
Flash
A[24:00]
D[15:0]
PB_RSTOUT#
RST#
D[07:00]
A[24:0]
OE#
WE#
DQ[7:0]
CE#
Intel®
28F256J3
256 Mbit
Flash
RST#
B6267-01