AT52BR1664-90CI Atmel, AT52BR1664-90CI Datasheet - Page 8

• Manufacturer Part Number: AT52BR1664-90CI
• Manufacturer: Atmel

Specifications of AT52BR1664-90CI

• Operating Supply Voltage (max): 3.3V
• Operating Temperature (max): 85C
• Mounting: Surface Mount
• Lead Free Status / RoHS Status: Not Compliant

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 program-
ming of a sector is locked down. When the device is in the software product identification
mode (see “Software Product Identification Entry/Exit” sections on page 24), 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 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 erase 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
maximum 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 15 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. 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 17 (for hardware operation) or “Software Product
Identification Entry/Exit” on page 24. The manufacturer and device codes are the same for
both modes.
128-BIT PROTECTION REGISTER: The 16-megabit Flash 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 13. To lock out block B, the four-bus cycle Lock Protection Register command
AT52BR1662(T)/1664(T)
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