AT45D01SSHB1D--B View Datasheet(PDF) - Unspecified

Part Name

Description

Manufacturer

AT45D01SSHB1D--B

1-megabit 2.7-volt Minimum DataFlash®

Unspecified 

AT45DB011D

8. Sector Protection

Two protection methods, hardware and software controlled, are provided for protection against

inadvertent or erroneous program and erase cycles. The software controlled method relies on

the use of software commands to enable and disable sector protection while the hardware con-

trolled method employs the use of the Write Protect (WP) pin. The selection of which sectors

that are to be protected or unprotected against program and erase operations is specified in the

nonvolatile Sector Protection Register. The status of whether or not sector protection has been

enabled or disabled by either the software or the hardware controlled methods can be deter-

mined by checking the Status Register.

8.1 Software Sector Protection

8.1.1

Enable Sector Protection Command

Sectors specified for protection in the Sector Protection Register can be protected from program

and erase operations by issuing the Enable Sector Protection command. To enable the sector

protection using the software controlled method, 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 command

sequence must be clocked in via the input pin (SI). After the last bit of the command sequence

has been clocked in, the CS pin must be deasserted after which the sector protection will be

enabled.

Table 8-1. Enable Sector Protection Command

Command

Enable Sector Protection

Byte 1

3DH

Byte 2

2AH

Byte 3

7FH

Byte 4

A9H

Figure 8-1. Enable Sector Protection

CS

SI

Opcode

Byte 1

Each transition

represents 8 bits

Opcode

Byte 2

Opcode

Byte 3

Opcode

Byte 4

8.1.2

Disable Sector Protection Command

To disable the sector protection using the software controlled method, 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 sequence for the Disable Sector Protection command must be clocked in via

the input pin (SI). After the last bit of the command sequence has been clocked in, the CS pin

must be deasserted after which the sector protection will be disabled. The WP pin must be in the

deasserted state; otherwise, the Disable Sector Protection command will be ignored.

Table 8-2. Disenable Sector Protection Command

Command

Disable Sector Protection

Byte 1

3DH

Byte 2

2AH

Byte 3

7FH

Byte 4

9AH

11

3639M–DFLASH–11/2017

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