28F004/400B3, 28F008/800B3, 28F016/160B3, 28F320B3
E
22
PRELIMINARY
3.3
Block Locking
The 3 Volt Advanced Boot Block flash memory
architecture
features
parameter blocks.
two
hardware-lockable
3.3.1
WP# = V
IL
FOR BLOCK LOCKING
The lockable blocks are locked when WP# = V
IL
;
any program or erase operation to a locked block
will result in an error, which will be reflected in the
status register. For top configuration, the top two
parameter blocks (blocks #69 and #70, blocks #37
and #38 for the 16-Mbit, blocks #21 and #22 for the
8-Mbit, blocks #13 and #14 for the 4-Mbit) are
lockable. For the bottom configuration, the bottom
two parameter blocks (blocks #0 and #1 for 4-/8-/
16-/32-Mbit) are lockable. Unlocked blocks can be
programmed or erased normally (unless V
PP
is
below V
PPLK
).
3.3.2
WP# = V
IH
FOR BLOCK UNLOCKING
WP# = V
IH
unlocks all lockable blocks.
These blocks can now be programmed or erased.
Note that RP# does not override WP# locking as in
previous Boot Block devices. WP# controls all block
locking and V
PP
provides protection against
spurious writes. Table 8 defines the write protection
methods.
Table 8. Write Protection Truth Table for
Advanced Boot Block Flash Memory Family
V
PP
WP#
RP#
Write Protection
Provided
X
X
V
IL
All Blocks Locked
V
IL
X
V
IH
All Blocks Locked
≥
V
PPLK
V
IL
V
IH
Lockable Blocks
Locked
≥
V
PPLK
V
IH
V
IH
All Blocks Unlocked
3.4
V
PP
Program and Erase
Voltages
Intel’s 3 Volt Advanced Boot Block products provide
in-system programming and erase at 2.7 V. For
customers requiring fast programming in their
manufacturing environment, 3 Volt Advanced Boot
Block includes an additional low-cost 12 V
programming feature.
The 12 V V
PP
mode enhances programming
performance during the short period of time typically
found in manufacturing processes; however, it is
not intended for extended use. 12 V may be applied
to V
PP
during program and erase operations for a
maximum of 1000 cycles on the main blocks and
2500 cycles on the parameter blocks. V
PP
may be
connected to 12 V for a total of 80 hours maximum.
Stressing the device beyond these limits may cause
permanent damage.
During read operations or idle times, V
PP
may be
tied to a 5 V supply. For program and erase
operations, a 5 V supply is not permitted. The V
PP
must be supplied with either 2.7 V–3.6 V or 11.4 V–
12.6 V during program and erase operations.
3.4.1
V
= V
FOR COMPLETE
PROTECTION
The V
PP
programming voltage can be held low for
complete write protection of all blocks in the flash
device. When V
PP
is below V
PPLK
, any program or
erase operation will result in a error, prompting the
corresponding status register bit (SR.3) to be set.
3.5
Power Consumption
ntel Flash devices have a tiered approach to
power savings that can significantly reduce overall
system power consumption. The Automatic Power
Savings (APS) feature reduces power consumption
when the device is selected but idle. If the CE# is
deasserted, the flash enters its standby mode,
where current consumption is even lower. The
combination of these features can minimize
memory power consumption, and therefore, overall
system power consumption.