MBM29SL160TD Fujitsu Microelectronics, Inc., MBM29SL160TD Datasheet - Page 15

• Manufacturer Part Number: MBM29SL160TD
• Description: Flash Memory 16m 2m X 8/1m X 16 Bit
• Manufacturer: Fujitsu Microelectronics, Inc.

Write
Sector Group Protection
Temporary Sector Group Unprotection
Device erasure and programming are accomplished via the command register. The contents of the register serve
as inputs to the internal state machine. The state machine outputs dictate the function of the device.
The command register itself does not occupy any addressable memory location. The register is a latch used to
store the commands, along with the address and data information needed to execute the command. The
command register is written by bringing WE to V
the falling edge of WE or CE, whichever happens later; while data is latched on the rising edge of WE or CE,
whichever happens first. Standard microprocessor write timings are used.
Refer to AC Write Characteristics and the Erase/Programming Waveforms for specific timing parameters.
The MBM29SL160TD/BD feature hardware sector group protection. This feature will disable both program and
erase operations in any combination of seventeen sector groups of memory. (See Tables 2.1 and 2.2). The sector
group protection feature is enabled using programming equipment at the user’s site. The device is shipped with
all sector groups unprotected.
To activate this mode, the programming equipment must force V
V
A
of the thirty nine (39) individual sectors, and tables 2.1 and 2.2 define the sector group address for each of the
seventeen (17) individual group 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 group addresses must be held constant
during the WE pulse. See figures 16 and 25 for sector group protection waveforms and algorithm.
To verify programming of the protection circuitry, the programming equipment must force V
with CE and OE at V
A
Otherwise the device will produce “0” for unprotected sector. In this mode, the lower order addresses, except
for A
and device codes. A
It is also possible to determine if a sector group 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
A
sector group. See Tables 6.1 and 6.2 for Autoselect codes.
This feature allows temporary unprotection of previously protected sector groups of the MBM29SL160TD/BD
devices in order to change data. The Sector Group Unprotection mode is activated by setting the RESET pin to
high voltage (V
the sector group addresses. Once the V
groups will be protected again. Refer to Figures 17 and 26.
ID
13
12
16
, and A
) while (A
, A
= 10V to 11V), CE = V
0
, A
15
, A
1
, and A
14
12
, A
) should be set to the sector to be protected. Tables 1.1 and 1.2 define the sector address for each
6
, A
13
ID
, and A
1
6
). During this mode, formerly protected sector groups can be programmed or erased by selecting
, A
are DON’T CARES. Address locations with A
0
) = (0, 1, 0) will produce a logical “1” code at device output DQ
-1
IL
and WE at V
requires to apply to V
12
) are the desired sector group address will produce a logical “1” at DQ
MBM29SL160TD
IL
and A
0
IH
= A
. Scanning the sector group addresses (A
6
ID
= V
is taken away from the RESET pin, all the previously protected sector
IL
IL
, A
on byte mode.
1
IL
= V
, while CE is at V
IH
. The sector group addresses (A
-10/-12
ID
1
= V
on address pin A
IL
IL
/MBM29SL160BD
and OE is at V
are reserved for Autoselect manufacturer
19
, A
9
IH
and control pin OE, (suggest
18
0
. Addresses are latched on
, A
for a protected sector.
19
17
, A
, A
ID
18
16
, A
on address pin A
, A
0
17
15
for a protected
, A
, A
19
16
14
, A
, A
, A
18
-10/-12
15
13
, A
, A
, and
17
14
,
9
,
15