AT45DB321E datasheet(44/80 Pages) RENESAS

44 / 80 page

DS-AT45DB321E-8784 Rev. N

Page 44

9/1/23

AT45DB321E Datasheet

10.2 Ultra-Deep Power-Down

The Ultra-Deep Power-Down mode allows the device to consume far less power compared to the standby and

Deep Power-Down modes by shutting down additional internal circuitry. Since almost all active circuitry is

shutdown in this mode to conserve power, the contents of the SRAM buffers cannot be maintained. Thus, any

data stored in the SRAM buffers are lost once the device enters the Ultra-Deep Power-Down mode.

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 are ignored. Since all commands are ignored, the mode can be used

as an extra protection mechanism against 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 are

ignored. When the CS pin is deasserted, the device enters the Ultra-Deep Power-Down mode within the

maximum time of tEUDPD.

The complete opcode must be clocked in 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 aborts the operation and return to the

standby mode once the CS pin is deasserted. Also, the device defaults to the standby mode after a power cycle.

The Ultra-Deep Power-Down command is ignored if an internally self-timed operation such as a program or erase

cycle is in progress. The Ultra-Deep Power-Down command must be reissued after the internally self-timed

operation has been completed in order for the device to enter the Ultra-Deep Power-Down mode.

Figure 18. Ultra-Deep Power-Down

SCK

MSB

ICC

Opcode

High-impedance

Ultra-Deep Power-Down Mode Current

Active Current

Standby Mode Current

tEUDPD

1111001

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