Rainbow Electronics AT29BV010A - Manual (Page 4)

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AT29BV010A
0519D–FLASH–05/02
and valid data will be read. Examining the toggle bit may begin at any time during a pro-
gram cycle.
OPTIONAL CHIP ERASE MODES: The entire device may be erased by using a
6-byte software code. Please see Software Chip Erase application note for details.
BOOT BLOCK PROGRAMMING LOCKOUT: The AT29BV010A has two designated
memory blocks that have a programming lockout feature. This feature prevents pro-
gramming of data in the designated block once the feature has been enabled. Each of
these blocks consists of 8K bytes; the programming lockout feature can be set indepen-
dently for either block. While the lockout feature does not have to be activated, it can be
activated for either or both blocks.
These two 8K memory sections are referred to as boot blocks. Secure code which will
bring up a system can be contained in a boot block. The AT29BV010A blocks are
located in the first 8K bytes of memory and the last 8K bytes of memory. The boot block
programming lockout feature can therefore support systems that boot from the lower
addresses of memory or the higher addresses. Once the programming lockout feature
has been activated, the data in that block can no longer be erased or programmed; data
in other memory locations can still be changed through the regular programming meth-
ods. To activate the lockout feature, a series of seven program commands to specific
addresses with specific data must be performed. Please see Boot Block Lockout Fea-
ture Enable Algorithm.
If the boot block lockout feature has been activated on either block, the chip erase func-
tion will be disabled.
BOOT BLOCK LOCKOUT DETECTION: A software method is available to determine
whether programming of either boot block section is locked out. See Software Product
Identification Entry and Exit sections. When the device is in the software product identifi-
cation mode, a read from location 00002H will show if programming the lower address
boot block is locked out while reading location 1FFF2H will do so for the upper boot
block. If the data is FE, the corresponding block can be programmed; if the data is FF,
the program lockout feature has been activated and the corresponding block cannot be
programmed. The software product identification exit mode should be used to return to
standard operation.
Absolute Maximum Ratings*
Temperature Under Bias ................................ -55 °C to +125°C *NOTICE: Stresses beyond those listed under “Absolute
Maximum Ratings” may cause permanent dam-
age to the device. This is a stress rating only and
functional operation of the device at these or any
other conditions beyond those indicated in the
operational sections of this specification is not
implied. Exposure to absolute maximum rating
conditions for extended periods may affect
device reliability.
Storage Temperature ..................................... -65 °C to +150°C
All Input Voltages (including NC Pins)
with Respect to Ground ...................................-0.6V to +6.25V
All Output Voltages
with Respect to Ground .............................-0.6V to V
CC
+ 0.6V
Voltage on A9 (including NC Pins)
with Respect to Ground ...................................-0.6V to +13.5V