W25P16VSFIG-TR Datasheet, PDF (23/43 Pages) Winbond – 8M-BIT, 16M-BIT AND 32M-BIT SERIAL FLASH MEMORY

W25P80 / W25P16 / W25P32
9.2.11 Power-down (B9h)
Although the standby current during normal operation is relatively low, standby current can be further
reduced with the Power-down instruction. The lower power consumption makes the Power-down
instruction especially useful for battery powered applications (See ICC1 and ICC2 in AC
Characteristics). The instruction is initiated by driving the /CS pin low and shifting the instruction code
“B9h” as shown in figure 13.
The /CS pin must be driven high after the eighth bit has been latched. If this is not done the Power-
down instruction will not be executed. After /CS is driven high, the power-down state will entered
within the time duration of tDP (See AC Characteristics). While in the power-down state only the
Release from Power-down / Device ID instruction, which restores the device to normal operation, will
be recognized. All other instructions are ignored. This includes the Read Status Register instruction,
which is always available during normal operation. Ignoring all but one instruction makes the Power
Down state a useful condition for securing maximum write protection. The device always powers-up in
the normal operation with the standby current of ICC1.
Figure 13. Deep Power-down Instruction Sequence Diagram
9.2.12 Release Power-down / Device ID (ABh)
The Release from Power-down / Device ID instruction is a multi-purpose instruction. It can be used to
release the device from the power-down state, obtain the devices electronic identification (ID) number
or do both.
When used only to release the device from the power-down state, the instruction is issued by driving
the /CS pin low, shifting the instruction code “ABh” and driving /CS high as shown in figure 14. After
the time duration of tRES1 (See AC Characteristics) the device will resume normal operation and other
instructions will be accepted. The /CS pin must remain high during the tRES1 time duration.
When used only to obtain the Device ID while not in the power-down state, the instruction is initiated
by driving the /CS pin low and shifting the instruction code “ABh” followed by 3-dummy bytes. The
Device ID bits are then shifted out on the falling edge of CLK with most significant bit (MSB) first as
shown in figure 15. The Device ID values for the W25P80, W25P16 and W25P32 are listed in
Manufacturer and Device Identification table. The Device ID can be read continuously. The instruction
is completed by driving /CS high.
Publication Release Date: December 11, 2005
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Revision J