MBM29DL800TA-70 Meet Spansion Inc., MBM29DL800TA-70 Datasheet - Page 19

• Manufacturer Part Number: MBM29DL800TA-70
• Description: Flash Memory Cmos 8m 1m ? 8 / 512k ? 16 Bit
• Manufacturer: Meet Spansion Inc.

Sector Protection
Temporary Sector Unprotection
RESET
Hardware Reset
The MBM29DL800TA/BA feature hardware sector protection. This feature will disable both program and erase
operations in any number of sectors (0 through 21). The sector protection feature is enabled using programming
equipment at the user’s site. The devices are shipped with all sectors unprotected. Alternatively, Fujitsu may
program and protect sectors in the factory prior to shiping the device.
To activate this mode, the programming equipment must force V
V
should be set to the sector to be protected. “Sector Address Tables (MBM29DL800TA/BA)” in ■FLEXIBLE
SECTOR-ERASE ARCHITECTURE define the sector address for each of the twenty two (22) individual sectors.
Programming of the protection circuitry begins on the falling edge of the WE pulse and is terminated with the
rising edge of the same. Sector addresses must be held constant during the WE pulse. See “(13) AC Waveforms
for Sector Protection” in ■TIMING DIAGRAM and “(5) Sector Protection Algorithm” in ■FLOW CHART for sector
protection waveforms and algorithm.
To verify programming of the protection circuitry, the programming equipment must force V
with CE and OE at V
(A
devices will read 00h for unprotected sector. In this mode, the lower order addresses, except for A
are DON’T CARES. Address locations with A
A
It is also possible to determine if a sector is protected in the system by writing an Autoselect command. Performing
a read operation at the address location XX02h, where the higher order addresses (A
and A
“MBM29DL800TA/BA Sector Protection Verify Autoselect Codes Table” and “Extended Autoselect Code Table”
in ■DEVICE BUS OPERATION for Autoselect codes.
This feature allows temporary unprotection of previously protected sectors of the MBM29DL800TA/BA devices
in order to change data. The Sector Unprotection mode is activated by setting the RESET pin to high voltage
(12 V). During this mode, formerly protected sectors can be programmed or erased by selecting the sector
addresses. Once the 12 V is taken away from the RESET pin, all the previously protected sectors will be protected
again. See “(14) Temporary Sector Unprotection Timing Diagram” in ■TIMING DIAGRAM and “(6) Temporary
Sector Unprotection Algorithm” in ■FLOW CHART.
The MBM29DL800TA/BA devices may be reset by driving the RESET pin to V
requirement and has to be kept low (V
Any operation in the process of being executed will be terminated and the internal state machine will be reset
to the read mode 20 µs after the RESET pin is driven low. Furthermore, once the RESET pin goes high, the
devices require an additional t
be in the standby mode for the duration of the pulse and all the data output pins will be tri-stated. If a hardware
reset occurs during a program or erase operation, the data at that particular location will be corrupted. Please
note that the RY/BY output signal should be ignored during the RESET pulse. See “(9) RESET/RY/BY Timing
Diagram” in ■TIMING DIAGRAM for the timing diagram. Refer to Temporary Sector Unprotection for additional
functionality.
ID
-1
6
, A
requires to apply to V
= 11.5 V), CE = V
1
12
, A
) are the desired sector address will produce a logical “1” at DQ
0
) = (0, 1, 0) will produce a logical “1” code at device output DQ
IL
IL
and WE at V
, and A
MB M29DL800TA
IL
on byte mode.
0
RH
= A
before it will allow read access. When the RESET pin is low, the devices will
6
IH
= V
Retired Product DS05-20860-7E_August 6, 2007
. Scanning the sector addresses (A
IL
) for at least 500 ns in order to properly reset the internal state machine.
IL
, A
1
1
= V
= V
IH
IL
. The sector addresses (A
are reserved for Autoselect manufacturer and device codes.
-70/90
ID
on address pin A
/MBM29DL800BA
0
18
0
for a protected sector. See
, A
for a protected sector. Otherwise the
18
17
, A
, A
IL
. The RESET pin has a pulse
17
16
9
, A
, A
and control pin OE, (suggest
16
15
, A
18
, A
, A
15
14
17
, A
ID
, A
, A
on address pin A
14
13
, A
16
, and A
, A
13
0
, A
, and A
15
, A
1
12
, and A
14
) while
-70/90
, A
12
13
)
,
9
6
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