at25dq321a ATMEL Corporation, at25dq321a Datasheet - Page 47

• Manufacturer Part Number: at25dq321a
• Description: 32-megabit 2.7-volt Minimum Spi Serial Flash Memory With Dual-i/o And Quad-i/o Support
• Manufacturer: ATMEL Corporation

8718A–DFLASH–04/10
12.3
Deep Power-Down
During normal operation, the device will be placed in the standby mode to consume less power as long as the CS
pin remains deasserted and no internal operation is in progress. The Deep Power-Down command offers the ability
to place the device into an even lower power consumption state called the Deep Power-Down mode.
When the device is in the Deep Power-Down mode, all commands including the Read Status Register command
will be ignored with the exception of the Resume from Deep Power-Down command. Since all commands will be
ignored, the mode can be used as an extra protection mechanism against program and erase operations.
Entering the Deep Power-Down mode is accomplished by simply asserting the CS pin, clocking in the opcode of
B9h, and then deasserting the CS pin. Any additional data clocked into the device after the opcode will be ignored.
When the CS pin is deasserted, the device will enter the Deep Power-Down mode within the maximum time of
t
The complete opcode must be clocked in before the CS pin is deasserted, and the CS pin must be deasserted on
a byte boundary (multiples of eight bits); otherwise, the device will abort the operation and return to the standby
mode once the CS pin is deasserted. In addition, the device will default to the standby mode after a power-cycle.
The Deep Power-Down command will be ignored if an internally self-timed operation such as a program or erase
cycle is in progress. The Deep Power-Down command must be reissued after the internally self-timed operation
has been completed in order for the device to enter the Deep Power-Down mode.
Figure 12-3. Deep Power-Down
EDPD
SCK
.
SO
CS
I
SI
CC
AT25DQ321A [Preliminary]
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