MBM29BS12DH Fujitsu Media Devices, MBM29BS12DH Datasheet - Page 28

• Manufacturer Part Number: MBM29BS12DH
• Description: (MBM29FS12DH / MBM29BS12DH) BURST MODE FLASH MEMORY CMOS 128M (8M X 16) BIT
• Manufacturer: Fujitsu Media Devices

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MBM29BS/FS12DH
<Protection>
(1) Write Protect (WP)[Hardware Protection]
(2) ACC Protect (ACC)[Hardware Protection2]
(3) New Sector Protection [Software Protection]
a) Persistent Protection Bit (PPB)
b) Dynamic Protection Bit (DPB)
HiddenROM area is devided into two regions, which are Factory Locked area and Customer Locked area. The
Factory Locked area is 64 words (address: 000000h - 00003Fh) that is programmed and locked at Fujitsu. The
Customer Locked area is also 64 words (address: 000040h - 00007Fh) that is programmed and locked at user.
The Factory indicator Bit (DQ7) is used to indicate whether or not the Factory Locked area is locked when shipped
from the factory. The Customer Indicator Bit (DQ6) is used to indicate whether or not the Customer Locked area
is locked. The Factory Locked area can be programmed and protected at Fujitsu ONLY and is always protected
when shipped from the factory regardless of the conditon whether or not this area is programmed. Therefore
this area has the Factory Indicator Bit (DQ7) permanently set to a "1". The Factory Locked area cannot be
modified in any way. The Customer Locked area is shipped unprotected, allowing users to utilize that area in
any manner they choose. The Customer Indicator Bit set to "0". Once the Customer Locked area is protected,
the Customer Indicator Bit will be permanently set to "1".
The MBM29BS/FS12DH features several levels of sector protection, which can disable both the program and
erase operations
The device features a hardware protection option using a write protect pin that prevents programming or erasing,
regardless of the state of the sector’s Persistent or Dynamic Protection Bits. The WP pin is associated with the
“outermost” 4 4K words on both ends of boot sectors (SA0-SA3 and SA266-SA269). The WP pin has no effect
on any other sector. When WP is taken to V
words sectors on both ends are disabled. By taking WP back to V
enabled for program and erase operations, depending upon the status of the individual sector Persistent or
Dynamic Protection Bits. If either of the four outermost sectors Persistent or Dynamic Protection Bits are pro-
grammed, program or erase operations are inhibited. If the sector Persistent or Dynamic Protection Bits are both
erased, the four outermost sectors are available for programming or erasing as long as WP remains at V
The device has also hardware protect feature by ACC pin. When ACC is V
at V
A command sector protection method that replaces the old V
A single Persistent (non-volatile) Protection Bit is assigned to a maximum four sectors (see the “sector group
address table” in “
All 4 K words boot-block sectors have individual sector Persistent Protection Bits (PPBs) for greater flexibility.
Each PPB is individually modifiable through the PPB Write Command.
Note : If a PPB requires erasure, all of the sector PPBs must first be preprogrammed prior to PPB erasing. All
PPBs erase in parallel, unlike programming where individual PPBs are programmable. It is the responsibility of
the user to perform the preprogramming operation. Otherwise, an already erased sector PPBs has the potential
of being over-erased. There is no hardware mechanism to prevent sector PPBs over-erasure.
A volatile protection bit is assigned for each sector. After power-up or hardware reset, the contents of all DPBs
is “0”. Each DPB is individually modifiable through the DPB Write Command.
When the parts are first shipped, the PPBs are cleared, the DPBs are cleared, and PPB Lock is defaulted to
power up in the cleared state - meaning the PPBs are changeable.
When the device is first powered on the DPBs power up cleared (sectors not protected). The Protection State
for each sector is determined by the logical OR of the PPB and the DPB related to that sector. For the sectors
that have the PPBs cleared, the DPBs control whether or not the sector is protected or unprotected. By issuing
the DPB Write/Erase command sequences, the DPBs will be set or cleared, thus placing each sector in the
protected or unprotected state. These are the so-called Dynamic Locked or Unlocked states. They are called
IH
for all other condition.
FLEXIBLE SECTOR-ERASE ARCHITECTURE” for specific sector protection groupings).
15
IL
, programming and erase operations of the “outermost” 4
ID
controlled protection method.
IH
, the “outermost” 4
IL
, all sectors are locked. Should be
4K words sectors are
IH
.
4K