MBM29QM12DH Fujitsu Microelectronics, Inc., MBM29QM12DH Datasheet - Page 29

• Manufacturer Part Number: MBM29QM12DH
• Description: Page Mode Flash Memory 128m 8m X 16 Bit
• Manufacturer: Fujitsu Microelectronics, Inc.

28
MBM29QM12DH
(3) Extended Sector Group Protection [Software Protection]
(4) New Sector Protection [Software Protection]
a) Persistent Protection Bit (PPB)
b) Dynamic Protection Bit (DPB)
when shipped from the factory regardless of the conditon whether or not this area is programmed. Therefore
this area has the Factory Indicator Bit (DQ
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".
In addition to normal sector group protection, the device has Extended Sector Group Protection as extended
function. This function enables protection of the sector group by forcing V
sequence. Unlike conventional procedures, it is not necessary to force V
The only RESET pin requires V
requires V
the command register. Then the sector group addresses pins (A
A
(setting V
(60h) should be written. A sector group is typically protected in 250 s. To verify programming of the protection
circuitry, the sector group addresses pins (A
A
command write, a logical “1” at device output DQ
output is logical “0”, write the extended sector group protection command (60h) again. To terminate the operation,
it is necessary to set RESET pin to V
“ TIMING DIAGRAM” and “Extended Sector Group Protection Algorithm” in “ FLOW CHART”.)
If Persistent Protection Bit Lock is set to "1", this mode is disabled.
A command sector protection method that replaces the old V
MBM29QM12DH support both V
period.
The persistent Sector Protection and the old V
Protection Lock Bit is settled.
A single Persistent (non-volatile) Protection Bit is assigned to a maximum four sectors (see the sector address
tables for specific sector protection groupings). 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
dynamic states because it is very easy to switch back and forth between the protected and unprotected conditions.
This allows software to easily protect sectors against inadvertent changes yet does not prevent the easy removal
of protection when changes are needed. The DPBs maybe set or cleared as often as needed.
12
4
, A
) and (A
3
, A
2
IL
, A
ID
7
for the other addresses pins is recommended) , and an extended sector group protection command
, A
on RESET pin. With this condition the operation is initiated by writing the set-up command (60h) in
1
, A
6
, A
0
)
5
, A
4
(0, 0, 0, 0, 0, 0, 1, 0) should be set a command (40h) should be written. Following the
, A
3
, A
2
, A
ID
1
ID
, A
-60
for sector group protection in this mode. The extended sector group protection
protection and Persistent Sector Protection. Both Protect supported as a shift
0
)
IH
. (Refer to “Extended Sector Gropup Protection Timing Diagram” in
(0, 0, 0, 0, 0, 0, 1, 0) should be set to the sector group to be protected
7
22
) permanently set to a "1". The Factory Locked area cannot be
, A
ID
21
controlled protection can go back each other until Persistent
0
, A
will produce a protected sector in the read operation. If the
20
, A
19
, A
ID
18
controlled protection method in future. However
, A
22
, A
17
, A
21
, A
16
ID
, A
on RESET pin and writes a command
ID
20
, A
15
and control timing for control pins.
, A
19
14
, A
, A
18
13
, A
and A
17
, A
16
12
, A
) and (A
15
, A
14
, A
7
, A
13
6
, A
and
5
,