AT45DB321E datasheet(17/69 Pages) RENESAS

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AT45DB321E

8784M–DFLASH–02/2022

6.12

Program/Erase Resume(1)

The Program/Erase Resume command allows a suspended program or erase operation to be resumed and continue

where it left off.

To perform a Program/Erase Resume, an opcode of D0h 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

program or erase operation currently suspended will be resumed within a time of t

RES. The PS1 bit, PS2 bit, or ES bit in

the Status Register will then be reset back to a Logic 0 state to indicate that the program or erase operation is no longer

suspended. In addition, the RDY/BUSY bit in the Status Register will indicate that the device is busy performing a

program or erase operation.

During a simultaneous Erase Suspend/Program Suspend condition, issuing the Program/Erase Resume command will

result in the program operation resuming first. After the program operation has been completed, the Program/Erase

Resume command must be issued again in order for the erase operation to be resumed.

While the device is busy resuming a program or erase operation, any attempts at issuing the Program/Erase Suspend

command will be ignored. Therefore, if a resumed program or erase operation needs to be subsequently suspended

again, the system must either wait the entire t

RES time before issuing the Program/Erase Suspend command, or it must

check the status of the RDY/BUSY bit or the appropriate PS1, PS2, or ES bit in the Status Register to determine if the

previously suspended program or erase operation has resumed.

6.13

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 controlled 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 determined by checking the Status Register.

6.14

Software Sector Protection

Software controlled protection is useful in applications in which the WP pin is not or cannot be controlled by a host

processor. In such instances, the WP pin may be left floating (the WP pin is internally pulled high) and sector protection

can be controlled using the Enable Sector Protection and Disable Sector Protection commands.

If the device is power cycled, then the software controlled protection will be disabled. Once the device is powered up, the

Enable Sector Protection command should be reissued if sector protection is desired and if the WP pin is not used.

6.14.1 Enable Sector Protection

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, a 4-byte command sequence of 3Dh,

2Ah, 7Fh, and A9h must be clocked into the device. After the last bit of the opcode sequence has been clocked in, the

CS pin must be deasserted to enable the Sector Protection.

Table 6-5.

Enable Sector Protection Command

Command

Byte 1

Byte 2

Byte 3

Byte 4

Enable Sector Protection

3Dh

2Ah

7Fh

A9h

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