AT45DB321D-SU-2.5 Atmel, AT45DB321D-SU-2.5 Datasheet - Page 14

• Manufacturer Part Number: AT45DB321D-SU-2.5
• Description: memory size:32mbit; supply voltage range:2.5v to 3.6v; memory case style:soic; no. of...
• Manufacturer: Atmel

7.1.3
7.1.4
Figure 7-3. Program Sector Protection Register
Read Sector Protection Register Command
To read the sector protection register, the CS pin must first be asserted. Once the CS pin has been asserted, an opcode of 32H
and three dummy bytes must be clocked in via the SI pin. After the last bit of the opcode and dummy bytes has been clocked in,
any additional clock pulses on the SCK pins will result in data for the content of the sector protection register being output on the
SO pin. The first byte corresponds to sector 0 (0a, 0b), the second byte corresponds to sector 1, and the last byte (byte 64)
corresponds to sector 63. Once the last byte of the sector protection register has been clocked out, any additional clock pulses
will result in undefined data being output on the SO pin. The CS pin must be deasserted to terminate the read sector protection
register operation and put the output into a high-impedance state.
Table 7-6.
Note:
Figure 7-4. Read Sector Protection Register
Various Aspects About the Sector Protection Register
The sector protection register is subject to a limit of 10,000 erase/program cycles. Users are encouraged to carefully evaluate
the number of times the sector protection register will be modified during the course of the application’s life cycle. If the
application requires the sector protection register to be modified more than the specified limit of 10,000 cycles because the
application needs to temporarily unprotect individual sectors (sector protection remains enabled while the sector protection
register is reprogrammed), then the application will need to limit this practice. Instead, a combination of temporarily unprotecting
individual sectors, along with disabling sector protection completely, will need to be implemented by the application to ensure
that the limit of 10,000 cycles is not exceeded.
CS
Command
Read sector protection register
CS
SO
SI
SI
Each transition
represents 8 bits
Each transition
represents 8 bits
Read Sector Protection Register Command
xx = Dummy byte
Opcode
Opcode
byte 1
Opcode
byte 2
X
Opcode
byte 3
X
Opcode
byte 4
Byte 1
X
32H
Data byte
Data byte
n
n
Byte 2
xxH
Data byte
Data byte
n + 1
n + 1
Atmel AT45DB321D
Byte 3
xxH
Data byte
Data byte
n + 63
n + 63
3597Q–DFLASH–6/11
Byte 4
xxH
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