at52br3244 ATMEL Corporation, at52br3244 Datasheet - Page 7

• Manufacturer Part Number: at52br3244
• Description: 32-megabit 2m X 16 Flash +4-megabit 256k X 16 / 8-megabit 512k X 16 Sram Stack Memory
• Manufacturer: ATMEL Corporation

AT52BR3244(T)/3248(T)
the specified t
cycle time. The Data Polling feature or the Toggle Bit feature may be
BP
used to indicate the end of a program cycle.
VPP PIN: The circuitry of the 32-megabit Flash is designed so that the device can be
programmed or erased from the V
power supply or from the VPP input pin. When V
CC
PP
is less than or equal to the VCC pin, the device selects the V
supply for programming
CC
and erase operations. When the VPP pin is greater than the V
supply, the device will
CC
select the V
input as the power supply for programming and erase operations. The
PP
device will allow for some variations between the V
input and the V
power supply in
PP
CC
its selection of V
or V
for program or erase operations. If the VPP pin is within 0.3V
CC
PP
of V
for 2.7V < V
< 3.3V, then the program or erase operations will use V
and dis-
CC
CC
CC
regard the V
input signal. When the V
signal is used to accelerate program and
PP
PP
erase operations, the V
must be in the 5V ± 0.5V or 12V ± 0.5V range to ensure
PP
proper operation. The V
pin can be left unconnected.
pp
SECTOR LOCKDOWN: Each sector has a programming lockdown feature. This feature
prevents programming of data in the designated sectors once the feature has been
enabled. These sectors can contain secure code that is used to bring up the system.
Enabling the lockdown feature will allow the boot code to stay in the device while data in
the rest of the device is updated. This feature does not have to be activated; any sec-
tor’s usage as a write protected region is optional to the user.
At power-up or reset all sectors are unlocked. To activate the lockdown for a specific
sector, the six-bus cycle Sector Lockdown command must be issued. Once a sector has
been locked down, the contents of the sector is read-only and cannot be erased or
programmed.
SECTOR LOCKDOWN DETECTION: A software method is available to determine if
programming of a sector is locked down. When the device is in the software product
identification mode (see Software Product Identification Entry and Exit sections) a read
from address location 00002H within a sector will show if programming the sector is
locked down. If the data on I/O0 is low, the sector can be programmed; if the data on
I/O0 is high, the program lockdown feature has been enabled and the sector cannot be
programmed. The software product identification exit code should be used to return to
standard operation.
SECTOR LOCKDOWN OVERRIDE: The only way to unlock a sector that is locked
down is through reset or power-up cycles. After power-up or reset, the content of a sec-
tor that is locked down can be erased and reprogrammed.
ERASE SUSPEND/ERASE RESUME: The Erase Suspend command allows the sys-
tem to interrupt a sector erase operation and then program or read data from a different
sector within the same plane. Since this device has a dual-plane architecture, there is
no need to use the Erase Suspend feature while erasing a sector when you want to read
data from a sector in the other plane. After the Erase Suspend command is given, the
device requires a maximum time of 15 µs to suspend the erase operation. After the
erase operation has been suspended, the plane that contains the suspended sector
enters the erase-suspend-read mode. The system can then read data or program data
to any other sector within the device. An address is not required during the Erase Sus-
pend command. During a sector erase suspend, another sector cannot be erased. To
resume the sector erase operation, the system must write the Erase Resume command.
The Erase Resume command is a one-bus cycle command, which does require the
plane address (determined by A20 - A19). The device also supports an erase suspend
during a complete chip erase. While the chip erase is suspended, the user can read
from any sector within the memory that is protected. The command sequence for a chip
erase suspend and a sector erase suspend are the same.
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