GD25LQ40xIGx 1.8V Uniform Sector Dual and Quad Serial Flash
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7.21. Release from Deep Power-Down and Read Device ID (RDI) (ABH)
The Release from Power-Down and Read Device ID is a multi-purpose command. It can be used to release the
device from the Power-Down state or obtain the devices electronic identification (ID) number.
To release the device from the Power-Down state, the command is issued by driving the CS# pin low, shifting
the instruction code “ABH” and driving CS# high as shown in Figure22. Release from Power-Down will take
the time duration of tRES1 (See AC Characteristics) before the device will resume normal operation and other
command are 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 command is initiated by
driving the CS# pin low and shifting the instruction code “ABH” followed by 3-dummy byte. The Device ID
bits are then shifted out on the falling edge of SCLK with most significant bit (MSB) first as shown in Figure23.
The Device ID value for the GD25LQ40 is listed in Manufacturer and Device Identification table. The Device
ID can be read continuously. The command is completed by driving CS# high.
When used to release the device from the Power-Down state and obtain the Device ID, the command is the
same as previously described, and shown in Figure23, except that after CS# is driven high it must remain high
for a time duration of tRES2 (See AC Characteristics). After this time duration the device will resume normal
operation and other command will be accepted. If the Release from Power-Down/Device ID command is issued
while an Erase, Program or Write cycle is in process (when WIP equal 1) the command is ignored and will not
have any effects on the current cycle.
Figure 22. Release Power-Down Sequence Diagram
CS
#
tRES
1
0
1
2
3
4
5
6
7
SCLK
SI
Command
ABH
Deep Power-down mode
Stand-by mode
Figure 22a. Release Power-Down Sequence Diagram (QPI)
CS#
tRES1
0
1
SCLK
Command
ABH
IO0
IO1
IO2
IO3
Deep Power-down mode
Stand-by mode
Rev.1.0
59 - 35
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