EN25D16
Figure 16. Deep Power-down Instruction Sequence Diagram
Release from Deep Power-down and Read Device ID (RDI)
Once the device has entered the Deep Power-down mode, all instructions are ignored except the
Release from Deep Power-down and Read Device ID (RDI) instruction. Executing this instruction
takes the device out of the Deep Power-down mode.
Please note that this is not the same as, or even a subset of, the JEDEC 16-bit Electronic Signature
that is read by the Read Identifier (RDID) instruction. The old-style Electronic Signature is supported
for reasons of backward compatibility, only, and should not be used for new designs. New designs
should, instead, make use of the JEDEC 16-bit Electronic Signature, and the Read Identifier (RDID)
instruction.
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 17.
After the time duration of t
(See AC Characteristics) the device will resume normal operation
RES1
and other instructions will be accepted. The CS# pin must remain high during the t
time
RES1
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 18. The Device ID value for the EN25D16 are listed in Table 5. The Device ID can
be read continuously. The instruction is completed by driving CS# high.
When Chip Select (CS#) is driven High, the device is put in the Stand-by Power mode. If the device
was not previously in the Deep Power-down mode, the transition to the Stand-by Power mode is
immediate. If the device was previously in the Deep Power-down mode, though, the transition to the
Standby Power mode is delayed by t
, and Chip Select (CS#) must remain High for at least
RES2
t
(max), as specified in Table 10. Once in the Stand-by Power mode, the device waits to be
RES2
selected, so that it can receive, decode and execute instructions.
Except while an Erase, Program or Write Status Register cycle is in progress, the Release from
Deep Power-down and Read Device ID (RDI) instruction always provides access to the 8bit Device
ID of the device, and can be applied even if the Deep Power-down mode has not been entered.
Any Release from Deep Power-down and Read Device ID (RDI) instruction while an Erase, Program
or Write Status Register cycle is in progress, is not decoded, and has no effect on the cycle that is in
progress.
This Data Sheet may be revised by subsequent versions
or modifications due to changes in technical specifications.
©2004 Eon Silicon Solution, Inc., www.essi.com.tw
21
Rev. B, Issue Date: 2008/06/23
EON [ EON SILICON SOLUTION INC. ]
