MBM29PL64LM SPANSION, MBM29PL64LM Datasheet - Page 28

• Manufacturer Part Number: MBM29PL64LM
• Description: Flash Memory 64 M (8M X 8/4M X 16) BIT
• Manufacturer: SPANSION

Extended Sector Group Protection
Query Command (CFI : Common Flash Memory Interface)
HiddenROM Mode
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
into the command register. Then the sector group addresses pins (A
A
pins is recommended), and write extended sector group protection command (60h). A sector group is typically
protected in 250 s. To verify programming of the protection circuitry, the sector group addresses pins (A
A
Following the command write, a logical “1” at device output DQ
operation. If the output data is logical “0”, write the extended sector group protection command (60h) again. To
terminate the operation, set RESET pin to V
in TIMING DIAGRAM and “Extended Sector Group Protection Algorithm” in FLOW CHART.)
The CFI (Common Flash Memory Interface) specification outlines device and host system software interrogation
handshake which allows specific vendor-specified software algorithms to be used for entire families of devices.
This allows device-independent, JEDEC ID-independent, and forward-and backward-compatible software sup-
port for the specified flash device families. Refer to CFI specification in detail.
The operation is initiated by writing the query command (98h) into the command register. Following the command
write, a read cycle from specific address retrieves device information. Please note that output data of upper byte
(DQ
command sequence into the register. (See “Common Flash Memory Interface Code” in DEVICE BUS OPER-
ATION.)
The HiddenROM (HiddenROM) feature provides a Flash memory region that the system may access through
a new command sequence. This is primarily intended for customers who wish to use an Electronic Serial Number
(ESN) in the device with the ESN protected against modification. Once the HiddenROM region is protected, any
further modification of that region is impossible. This ensures the security of the ESN once the product is shipped
to the field.
The HiddenROM region is 256 bytes / 128 words in length. After the system writes the HiddenROM Entry
command sequence, it may read the HiddenROM region by using device addresses A
“0”). That is, the device sends only program command that would normally be sent to the address to the
HiddenROM region. This mode of operation continues until the system issues the Exit HiddenROM command
sequence, or until power is removed from the device. On power-up, or following a hardware reset, the device
reverts to sending commands to the address.
If you request Fujitsu to program the ESN in the device, please contact a Fujitsu representative for more infor-
mation.
3
19
(1) HiddenROM Region
, A
, A
15
2
, A
18
to DQ
, A
1
, A
ID
17,
0
on RESET pin. With this condition, the operation is initiated by writing the set-up command (60h)
8
) = (0, 0, 0, 1, 0) should be set to the sector group to be protected (set V
A
) is “0”. Refer to the CFI code table. To terminate operation, it is necessary to write the Reset
16
and A
15
) and (A
ID
for sector group protection in this mode. The extended sector group protection
6
, A
3
, A
2
, A
IH
1
. (Refer to the “Extended Sector Group Protection Timing Diagram”
, A
0
) = (0, 0, 0, 1, 0) should be set and write a command (40h).
0
will produce for protected sector in the read
MBM29PL64LM
21
, A
ID
on RESET pin and writes a command
ID
20
, A
and control timing for control pins.
19
, A
18
, A
IL
6
17,
for the other addresses
to A
A
16
0
and A
(A
21
to A
15
) and (A
15
21
90/10
are all
, A
20
6
,
,
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