MD4331-d1G-MECH M-Systems Inc., MD4331-d1G-MECH Datasheet - Page 43

• Manufacturer Part Number: MD4331-d1G-MECH
• Description: Mobile Diskonchip G3 Data Sheet
• Manufacturer: M-Systems Inc.

5.
5.1
Mobile DiskOnChip G3 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 maximum 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 read/write protection, the protection key (i.e., password) must be used, as
follows:
•
•
Mobile DiskOnChip G3 has an additional hardware safety measure. If the Lock option is enabled
(by means of software) and the LOCK# signal 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# signal must be asserted during DFORMAT (and later when the
partition is defined as changeable) to enable the additional hard-wired safety lock.
It is possible to set the Lock option for one session only; that is, until the next power-up or reset.
This Sticky Lock feature can be useful when the boot code in the boot partition must be read/write
protected. Upon power-up, the boot code must be unprotected so the CPU can run it directly from
Mobile DiskOnChip G3. At the end of the boot process, protection can be set until the next power-
up or reset.
Setting the Sticky Lock (SLOCK) bit in the Output Control register to 1 has the same effect as
asserting the LOCK# signal. Once set, SLOCK can only be cleared by asserting the RSTIN# input.
Like the LOCK# input, the assertion of this bit prevents the protection key from disabling the
protection for a given partition. For more information, see Section 3.4.5. The target partition does
require mounting before calling a hardware protection routine.
The only way to read or write from a protected partition is to use insert the key (even DFORMAT
does not remove the protection). This is also true for modifying its attributes (protection key, read,
write and lock). Read/write protection is disabled in each of the following events:
•
•
•
•
For further information on hardware protection, please refer to the TrueFFS Software Development
Kit (SDK) developer guide.
40
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.
H
Method of Operation
ARDWARE
P
ROTECTION
Data Sheet, Rev. 1.0
Mobile DiskOnChip G3
91-SR-011-05-8L