MBM29PL64LM SPANSION, MBM29PL64LM Datasheet - Page 29

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

28
MBM29PL64LM
The device has a HiddenROM area with One Time Protect function. This area is to enter the security code and
to unable the change of the code once set. Programming is allowed in this area until it is protected. However,
once it gets protected, it is impossible to unprotect. Therefore, extreme caution is required.
The HiddenROM area is 256 bytes / 128 words. This area is in SA0 . Therefore, write the HiddenROM entry
command sequence to enter the HiddenROM area. It is called HiddenROM mode when the HiddenROM area
appears.
Sectors other than the block area SA0 can be read during HiddenROM mode. Read/program of the HiddenROM
area is possible during HiddenROM mode. Write the HiddenROM reset command sequence to exit the Hidden-
ROM mode. Note that any other commands should not be issued than the HiddenROM program/protection/reset
commands during the HiddenROM mode. When you issue the other commands including the suspend resume
capability, send the HiddenROM reset command first to exit the HiddenROM mode and then issue each com-
mand.
To program the data to the HiddenROM area, write the HiddenROM program command sequence during Hid-
denROM mode. This command is the same as the usual program command, except that it needs to write the
command during HiddenROM mode. Therefore the detection of completion method is the same as in the past,
using the DQ
If an address not in the HiddenROM area is selected, the previous data will be deleted.
During the write into the HiddenROM region, the program suspend command issuance is prohibited.
There are two methods to protect the HiddenROM area. One is to write the sector group protect setup command
(60h) , set the sector address in the HiddenROM area and (A
sector group protect command (60h) during the HiddenROM mode. The same command sequence may be used
because it is the same as the extension sector group protect in the past, except that it is in the HiddenROM
mode and does not apply high voltage to the RESET pin. Please refer to above mentioned “Extended Sector
Group Protection” for details of sector group protect setting.
The other method is to apply high voltage (V
and (A
protect circuit, apply high voltage (V
in the HiddenROM area, and read. When “1” appears on DQ
on DQ
method because other than the HiddenROM mode, it is the same as the sector group protect previously men-
tioned.
Take note that other sector groups will be affected if an address other than those for the HiddenROM area is
selected for the sector group address, so please be careful. Pay close attention that once it is protected, protection
CANNOT BE CANCELLED.
(2) HiddenROM Entry Command
(3) HiddenROM Program Command
(4) HiddenROM Protect Command
0
6
, A
if it is not protected. Apply write pulse again. The same command sequence could be used for the above
3
, A
7
2
data pooling, DQ
, A
1
, A
0
)
(0, 0, 0, 1, 0) , and apply the write pulse during the HiddenROM mode. To verify the
6
90/10
Toggle bit or RY/BY. You should pay attention to the address to be programmed.
ID
) to A
9
, specify (A
ID
) to A
9
and OE, set the sector address in the HiddenROM area
6
, A
3
, A
0
, the protect setting is completed. “0” will appear
2
6
, A
, A
1
3
, A
, A
0
2
)
, A
(0, 0, 0, 1, 0) and the sector address
1
, A
0
)
(0, 0, 0, 1, 0) , and write the