MBM29LV160TM-BM90 Meet Spansion Inc., MBM29LV160TM-BM90 Datasheet - Page 20

• Manufacturer Part Number: MBM29LV160TM-BM90
• Description: Flash Memory Cmos 16 M 2m ? 8/1m ? 16 Bit Mirrorflashtm*
• Manufacturer: Meet Spansion Inc.

20
MBM29LV160TM/BM
Write
Sector Protection
Temporary Sector Unprotection
Hardware Reset
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 device function.
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 com-
mand register is written by bringing WE to V
falling edge of WE or CE, whichever starts later; while data is latched on the rising edge of WE or CE, whichever
starts first. Standard microprocessor write timings are used.
Refer to AC Write Characteristics and “Alternate WE Controlled Program Operation Timing Diagram” in
■SWITCHING WAVEFORMS for specific timing parameters.
The device features hardware sector protection. This feature will disable both program and erase operations in
any combination of 35 sectors of memory. The user‘s side can use the sector protection using programming
equipment. The device is shipped with all sectors that are unprotected.
To activate it, the programming equipment must force V
A
to be protected. “Sector Address Table (MBM29LV160TM)” and “Sector Address Table (MBM29LV160BM)” in
■DEVICE BUS OPERATION defines the sector address for each of the thirty-five (35) individual sectors. Pro-
gramming 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 “Sector Protection Timing
Diagram” in ■SWITCHING WAVEFORMS and “Sector Protection Algorithm” in ■FLOW CHART for sector
protection timing diagram and algorithm.
To verify programming of the protection circuitry, the programming equipment must force V
with CE and OE at V
while (A
the device will produce “0” for unprotected sectors. In this mode, the lower order addresses, except for A
and A
device codes. 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
A
Protection Verify Autoselect Codes” in ■DEVICE BUS OPERATION for Autoselect codes.
This feature allows temporary unprotection of previously protected sectors of the devices in order to change
data. The Sector Unprotection mode is activated by setting the RESET pin to high voltage (V
mode, formerly protected sectors can be programmed or erased by selecting the sector addresses. Once the
V
“Temporary Sector Unprotection Timing Diagram” in ■SWITCHING WAVEFORMS and “Temporary Sector Un-
protection Algorithm” in ■FLOW CHART.
The devices may be reset by driving the RESET pin to V
and has to be kept low (V
in the process of being executed will be terminated and the internal state machine will be reset to the read mode
“t
additional “t
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.
READY
6
13
ID
= A
, and A
is taken away from the RESET pin, all the previously protected sectors will be protected again. Refer to
6
” after the RESET pin is driven low. Furthermore, once the RESET pin goes high, the devices require an
0
can be either High or Low. Address locations with A
= V
6
, A
12
IL
1
) are the desired sector address will produce a logical “1” at DQ
RH
, A
, A
” before it will allow read access. When the RESET pin is low, the devices will be in the standby
1
0
) = (0, 1, 0) will produce a logical “1” code at device output DQ
-1
= V
requires applying to V
IH
. The sector addresses (A
IL
and WE at V
IL
) for at least “t
IH
Retired Product DS05-20906-4E_July 31, 2007
. Scanning the sector addresses (A
IL
RP
on Byte mode.
90
” in order to properly reset the internal state machine. Any operation
IL
, while CE is at V
19
, A
18
, A
17
ID
, A
IL
on address pin A
1
16
from V
= V
, A
IL
IL
and OE is at V
15
are reserved for Autoselect manufacturer and
, A
IH
. The RESET pin has a pulse requirement
14
, A
13
19
, and A
, A
0
9
for a protected sector. See “Sector
0
and control pin OE, CE = V
18
for a protected sector. Otherwise
IH
, A
. Addresses are latched on the
12
17
) should be set to the sector
, A
16
19
, A
, A
15
ID
18
, A
, A
on address pin A
14
17
ID
, A
, A
). During this
13
16
, and A
, A
15
IL
, A
0
, A
and
12
14
1
9
)
,
,