Manual

AT25DQ161 [DATASHEET]

8671C–DFLASH–11/2012

9. Protection Commands and Features

9.1 Write Enable

The Write Enable command is used to set the Write Enable Latch (WEL) bit in the Status Register to a Logical 1 state.

The WEL bit must be set before a Byte/Page Program, erase, Protect Sector, Unprotect Sector, Sector Lockdown,

Freeze Sector Lockdown State, Program OTP Security Register, Write Status Register, or Write Configuration Register

command can be executed. This makes the issuance of these commands a two step process, thereby reducing the

chances of a command being accidentally or erroneously executed. If the WEL bit in the Status Register is not set prior to

the issuance of one of these commands, then the command will not be executed.

To issue the Write Enable command, the

CS pin must first be asserted and the opcode of 06h must be clocked into the

device. No address bytes need to be clocked into the device, and any data clocked in after the opcode will be ignored.

When the

CS pin is deasserted, the WEL bit in the Status Register will be set to a Logical 1. The complete opcode must

be clocked into the device before the

CS pin is deasserted, and the CS pin must be deasserted on an even byte

boundary (multiples of eight bits); otherwise, the device will abort the operation and the state of the WEL bit will not

change.

Figure 9-1. Write Enable

SCK

MSB

2310

00000110

6754

Opcode

High-impedance