MD2241-D128-V3 M-Systems Inc., MD2241-D128-V3 Datasheet - Page 17

• Manufacturer Part Number: MD2241-D128-V3
• Description: Diskonchip Dimm Plus
• Manufacturer: M-Systems Inc.

4.
4.1
DiskOnChip DIMM Plus enables the user to define two partitions that are protected (in hardware) against any
combination of read or write operations. The two protected areas can be configured as read protected or write-
protected, and are protected by a protection key (i.e. password) defined by the user. Each of the protected areas can
be configured separately and can function separately, providing maximal flexibility for the user.
The size and protection attributes (protection key/read/write/changeable/lock) of the protected partition are defined
in the media formatting stage (DFORMAT utility or the format function in the TrueFFS SDK).
In order to set or remove a read/write protection, the protection key (i.e., password) must be used, as follows:
DiskOnChip DIMM Plus has an additional hardware safety measurement. If the Lock option is enabled (by means
of software) and the LOCK# pin is asserted, the protected partition has an additional hardware lock that prevents
read/write access to the partition, even with the use of the correct protection key. The LOCK# pin must be asserted
during DFORMAT (and later when the partition is defined as changeable) to enable the additional hardware safety
lock.
Note: The target volume (i.e. partition) does not have to be mounted before calling a hardware protection routine.
Only one partition can be defined as “changeable”; i.e., its password and attributes are fully configurable at any time
(from read to write, both or none and vise versa). Note that “un-changeable” partition attributes cannot be changed
unless the media is reformatted.
A change of any of the protection attributes causes a reset of the protection mechanism and consequently the
removal of all device protection keys. That is, if the protection attributes of one partition are changed, the other
partition will lose its key-protected read/write protection.
The only way to read or write from a read or write protected partition is to use the insert key call (even DFORMAT
does not remove the protection). This is also true for modifying its attributes (key, read, write and lock enable state).
Read/write protection is disabled in each one of the following events:
For further information on hardware protection, please refer to TrueFFS SDK User Manual or application note AP-
DOC-057 Protection and Security-Enabling Features in DiskOnChip Millennium Plus.
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Hardware Protection
Method of Operation
Insert the protection key to remove read/write protection.
Remove the protection key to set read/write protection.
Power-down
Change of any protection attribute (not necessarily in the same partition)
Write operation to the IPL area
Removal of the protection key.
Preliminary Data Sheet, Rev. 1.2
DiskOnChip DIMM Plus
94-SR-002-08-8L