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3.5 Flash Memory
The IMP2B supports up to 256 MBytes of Flash memory, with 128 MBytes fitted as
standard. This memory is implemented using Spansion S29GL512P Flash devices.
These are configured as two banks of 16-bit wide devices, accessed via the MV64560
Device Bus. The Flash supports burst accesses to allow for maximum bus bandwidth
and must be written to as 16-bits. The Flash is arranged in 128 KByte sectors and has
an erase capacity of 100,000 cycles per sector. For further details, see the S29GL512P
512 Mb page-mode Flash data sheet.
The following table shows the Flash options available for the IMP2B:
Table 3-2 Flash Options
Flash Size (MBytes)
128
256
The Flash is divided into two areas: Boot Flash and User Flash. The top 8 MBytes of
the first bank are reserved as Boot Flash. The remainder of the Flash memory is
allocated as User Flash.
3.5.1 Boot Flash
The Boot Flash, in the top 8 MBytes of Flash memory, holds initialization and
operating system boot routines. This area is divided into four 2 MByte boot images
that may be selected using links
Table 3-3 Boot Image Selection
1-2
Out
In
Out
In
The Recovery boot image contains a 128 KByte factory-programmed boot image,
allowing the Flash to be reprogrammed if all other boot images become unusable.
This area is not writeable by the user. The remainder of this 2 MByte boot image can
be used to store BIT results, but can only be accessed through DEV_CS3.
Publication No. IMP2B-0HH/5
LINK
http://www.spansion.com/support/technical_documents/flash_datasheets.html
Banks
Flash Bank Organization
2
2 x 512Mbit
2
2 x 1024Mbit
NOTE
Integrity of Flash data cannot be guaranteed if a hard reset occurs during a Flash write cycle.
3-4
Boot Image Selected
Out
Normal
Out
Alternate
In
Recovery/BIT
In
Extended
P2 1-2 and 3-4
as follows:
Functional Description 19
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