AT52BC6402AT-70CU Atmel, AT52BC6402AT-70CU Datasheet - Page 8

• Manufacturer Part Number: AT52BC6402AT-70CU
• Manufacturer: Atmel

Specifications of AT52BC6402AT-70CU

• Operating Supply Voltage (max): 3.1V
• Operating Temperature (max): 85C
• Mounting: Surface Mount
• Lead Free Status / RoHS Status: Compliant

128-BIT PROTECTION REGISTER: The 64-Mbit 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 reprogrammed. 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 table on page 12. To lock out block B, the four-bus cycle lock pro-
tection register command must be used as shown in the Command Definition 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 status of
Block B Protection command is given. 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 Address-
ing Table on page 13 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 com-
mand must be given prior to performing any other operation.
CFI: Common Flash Interface (CFI) is a published, standardized data structure that
may be read from a Flash device. CFI allows system software to query the installed
device to determine the configurations, various electrical and timing parameters, and
functions supported by the device. CFI is used to allow the system to learn how to inter-
face to the Flash device most optimally. The two primary benefits of using CFI are ease
of upgrading and second source availability. The command to enter the CFI Query
mode is a one-bus cycle command which requires writing data 98h to address 55h. The
CFI Query command can be written when the device is ready to read data or can also
be written when the part is in the product ID mode. Once in the CFI Query mode, the
system can read CFI data at the addresses given in Table 4 on page 24. To exit the CFI
Query mode, the product ID exit command must be given. If the CFI Query command is
given while the part is in the product ID mode, then the product ID exit command must
first be given to return the part to the product ID mode. Once in the product ID mode, it
will be necessary to give another product ID exit command to return the part to the read
mode.
HARDWARE DATA PROTECTION: Hardware features protect against inadvertent pro-
grams to the 64-Mbit device in the following ways: (a) V
sense: if V
is below 1.8V
CC
CC
(typical), the program function is inhibited. (b) V
power-on delay: once V
has
CC
CC
reached the V
sense level, the device will automatically time-out 10 ms (typical)
CC
before programming. (c) Program inhibit: holding any one of OE low, CE high or WE
high inhibits program cycles. (d) Noise filter: pulses of less than 15 ns (typical) on the
WE or CE inputs will not initiate a program cycle. (e) V
is less than V
.
PP
ILPP
INPUT LEVELS: While operating with a 2.7V to 3.1V power supply, the address inputs
and control inputs (OE, CE and WE) may be driven from 0 to 5.5V without adversely
affecting the operation of the device. The I/O lines can be driven from 0 to V
+ 0.6V.
CCQ
AT52BC6402A(T)
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3441B–STKD–11/04