MBM29PL65LM90TN datasheet(23/56 Pages) SPANSION

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MBM29PL65LM-90/10

HiddenROM Entry Command

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. Program/erase is possible in this area until it is protected. However

once it is protected, it is impossible to unprotect. Therefore extreme caution is required.

HiddenROM area is 128 words. This area is normally the “outermost” 8K words boot block area. 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.

HiddenROM Program Command

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 program command in usual except to write the command

during HiddenROM mode. Therefore the detection of completion method is the same as using the DQ7 data

polling, and DQ6 toggle bit. Need to pay attention to the address to be programmed. If the address other than

the HiddenROM area is selected to program, data of the address are changed.During the write into the Hidden-

ROM region, the program suspend command issuance is prohibited.

HiddenROM Protect Command

The method to protect the HiddenROM is to apply high voltage (VID) to A9 and OE, set the sector address in the

HiddenROM area and (A6, A3, A2, A1, A0)

= (0, 0, 0, 1, 0) , and apply the write pulse 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 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.

Other sector will be effected if the address other than those for HiddenROM area is selected for the sector

address, so please be carefull. Once it is protected, protection can not be cancelled, so please pay the closest

attention.

Write Operation Status

Hardware Sequence Flags

Detailed in “Hardware Sequence Flags” are all the status flags which can determine the status of the bank for

the current mode operation. During sector erase, the part provides the status flags automatically to the I/O ports.

The information on DQ2 is address-sensitive. This means that if an address from an erasing sector is consecu-

tively read, the DQ2 bit will toggle. However, DQ2 will not toggle if an address from a non-erasing sector is

consecutively read. This allows users to determine which sectors are in erase and which are not.

MBM29PL65LM90TN Datasheet(PDF) 23 Page - SPANSION