Rainbow Electronics AT45DB021E - Manual (Page 32)

32 AT45DB021E [PRELIMINARY DATASHEET]
8789B–DFLASH–11/2012
10.2.1 Exit Ultra-Deep Power-Down
To exit from the Ultra-Deep Power-Down mode, the CS pin must simply be pulsed by asserting the CS pin, waiting the
minimum necessary t
CSLU
time, and then deasserting the CS pin again. To facilitate simple software development, a
dummy byte opcode can also be entered while the CS pin is being pulsed; the dummy byte opcode is simply ignored by
the device in this case. After the CS pin has been deasserted, the device will exit from the Ultra-Deep Power-Down mode
and return to the standby mode within a maximum time of t
XUDPD
. If the CS pin is reasserted before the t
XUDPD
time has
elapsed in an attempt to start a new operation, then that operation will be ignored and nothing will be performed. The
system must wait for the device to return to the standby mode before normal command operations such as Continuous
Array Read can be resumed.
Since the contents of the Buffer cannot be maintained while in the Ultra-Deep Power-Down mode, the Buffer will contain
undefined data when the device returns to the standby mode.
Figure 10-4. Exit Ultra-Deep Power-Down
CS
SO
I
CC
High-impedance
Ultra-Deep Power-Down Mode Current
Active Current
Standby Mode Current
t
XUDPD
t
CSLU