25

AT25DF256

DS-25DF256–035D–2/2017

Figure 12-4. Resume from Deep Power-Down

12.5 Ultra-Deep Power-Down

The Ultra-Deep Power-Down mode allows the device to further reduce its energy consumption compared to the existing

standby and Deep Power-Down modes by shutting down additional internal circuitry. When the device is in the Ultra-

Deep Power-Down mode, all commands including the Status Register Read and Resume from Deep Power-Down

commands will be ignored. Since all commands will be ignored, the mode can be used as an extra protection mechanism

against inadvertent or unintentional program and erase operations. Entering the Ultra-Deep Power-Down mode is

accomplished by simply asserting the CS pin, clocking in the opcode 79h, 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

The complete opcode must be clocked in before the CS pin is deasserted; 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 Ultra-Deep Power-Down command will be ignored if an internally self-timed operation such as a

program or erase cycle is in progress.

SCK

CS

SI

SO

MSB

23

1

0

10101011

67

5

4

OPCODE

HIGH-IMPEDANCE

Deep Power-Down Mode Current

Active Current

Standby Mode Current