AT45DB321D-MU SL383 Atmel, AT45DB321D-MU SL383 Datasheet - Page 15

• Manufacturer Part Number: AT45DB321D-MU SL383
• Manufacturer: Atmel

Specifications of AT45DB321D-MU SL383

• Density: 32Mb
• Access Time (max): 6ns
• Interface Type: Serial (SPI)
• Address Bus: 1b
• Operating Supply Voltage (typ): 3.3V
• Operating Temp Range: -40C to 85C
• Package Type: MLF EP
• Program/erase Volt (typ): 2.7 to 3.6V
• Sync/async: Synchronous
• Operating Temperature Classification: Industrial
• Operating Supply Voltage (min): 2.7V
• Operating Supply Voltage (max): 3.6V
• Word Size: 8b
• Number Of Words: 4M
• Supply Current: 15mA
• Mounting: Surface Mount
• Pin Count: 8
• Lead Free Status / RoHS Status: Compliant

9.1.1
9.1.2
3597M–DFLASH–3/09
Erase Sector Protection Register Command
Program Sector Protection Register Command
In order to modify and change the values of the Sector Protection Register, it must first be
erased using the Erase Sector Protection Register command.
To erase the Sector Protection Register, the CS pin must first be asserted as it would be with
any other command. Once the CS pin has been asserted, the appropriate 4-byte opcode
sequence must be clocked into the device via the SI pin. The 4-byte opcode sequence must
start with 3DH and be followed by 2AH, 7FH, and CFH. After the last bit of the opcode sequence
has been clocked in, the CS pin must be deasserted to initiate the internally self-timed erase
cycle. The erasing of the Sector Protection Register should take place in a time of t
which time the Status Register will indicate that the device is busy. If the device is powered-
down before the completion of the erase cycle, then the contents of the Sector Protection Regis-
ter cannot be guaranteed.
The Sector Protection Register can be erased with the sector protection enabled or disabled.
Since the erased state (FFH) of each byte in the Sector Protection Register is used to indicate
that a sector is specified for protection, leaving the sector protection enabled during the erasing
of the register allows the protection scheme to be more effective in the prevention of accidental
programming or erasing of the device. If for some reason an erroneous program or erase com-
mand is sent to the device immediately after erasing the Sector Protection Register and before
the register can be reprogrammed, then the erroneous program or erase command will not be
processed because all sectors would be protected.
Figure 9-2.
Once the Sector Protection Register has been erased, it can be reprogrammed using the Pro-
gram Sector Protection Register command.
To program the Sector Protection Register, the CS pin must first be asserted and the appropri-
ate 4-byte opcode sequence must be clocked into the device via the SI pin. The 4-byte opcode
sequence must start with 3DH and be followed by 2AH, 7FH, and FCH. After the last bit of the
opcode sequence has been clocked into the device, the data for the contents of the Sector Pro-
tection Register must be clocked in. As described in
contains 64 bytes of data, so 64 bytes must be clocked into the device. The first byte of data cor-
responds to sector 0, the second byte corresponds to sector 1, and so on with the last byte of
data corresponding to sector 63.
Command
Erase Sector Protection Register
Erase Sector Protection Register
CS
SI
Each transition
represents 8 bits
Opcode
Byte 1
Byte 1
Opcode
Byte 2
3DH
Section
Opcode
Byte 3
Byte 2
2AH
9.1, the Sector Protection Register
Opcode
Byte 4
Byte 3
7FH
Byte 4
PE
CFH
, during
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