at52br3224a ATMEL Corporation, at52br3224a Datasheet - Page 9

• Manufacturer Part Number: at52br3224a
• Description: At52br3224a 32-megabit Flash + 4-megabit/ 8-megabit Sram Stack Memory
• Manufacturer: ATMEL Corporation

AT52BR3224A(T)/3228A(T)
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 sector that is
locked down can be erased and reprogrammed.
ERASE SUSPEND/ERASE RESUME: The Erase Suspend command allows the system to
interrupt a sector or chip erase operation and then program or read data from a different sector
within the memory. After the Erase Suspend command is given, the device requires a maxi-
mum time of 15 µs to suspend the erase operation. After the erase operation has been
suspended, the system can then read data or program data to any other sector within the
device. An address is not required during the Erase Suspend 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. 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 pro-
tected. The command sequence for a chip erase suspend and a sector erase suspend are the
same.
PROGRAM SUSPEND/PROGRAM RESUME: The Program Suspend command allows the
system to interrupt a programming operation and then read data from a different word within
the memory. After the Program Suspend command is given, the device requires a maximum
of 20 µs to suspend the programming operation. After the programming operation has been
suspended, the system can then read data from any other word within the device that is not
contained in the sector in which the programming operation was suspended. An address is not
required during the program suspend operation. To resume the programming operation, the
system must write the Program Resume command. The program suspend and resume are
one-bus cycle commands. The command sequence for the erase suspend and program sus-
pend are the same, and the command sequence for the erase resume and program resume
are the same.
PRODUCT IDENTIFICATION: The product identification mode identifies the device and man-
ufacturer as Atmel. It may be accessed by hardware or software operation. The hardware
operation mode can be used by an external programmer to identify the correct programming
algorithm for the Atmel product.
For details, see “Operating Modes” on page 20 (for hardware operation) or “Software Product
Identification Entry/Exit” sections on page 27. The manufacturer and device codes are the
same for both modes.
128-BIT PROTECTION REGISTER: The device contains a 128-bit register that can be used
for security purposes in system design. The protection register is divided into two 64-bit
blocks. The two blocks are designated as block A and block B. The data in block A is
non-changeable and is programmed at the factory with a unique number. The data in block B
is programmed by the user and can be locked out such that data in the block cannot be repro-
grammed. To program block B in the protection register, the four-bus cycle Program
Protection Register command must be used as shown in the “Command Definition in Hex”
table on page 14. To lock out block B, the four-bus cycle Lock Protection Register command
must be used as shown in the “Command Definition in Hex” table. Data bit D1 must be zero
during the fourth bus cycle. All other data bits during the fourth bus cycle are don’t cares. To
determine whether block B is locked out, the Product ID Entry command is given followed by a
read operation from address 80H. If data bit D1 is zero, block B is locked. If data bit D1 is one,
block B can be reprogrammed. Please see the “Protection Register Addressing Table” on
page 15 for the address locations in the protection register. To read the protection register, the
Product ID Entry command is given followed by a normal read operation from an address
within the protection register. After determining whether block B is protected or not, or reading
the protection register, the Product ID Exit command must be given prior to performing any
other operation.
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