ACE25AB400G

Serial NOR Flash Memory 4M bits 3.0V Dual I/O Serial Flash Memory with 4KB Uniform Sector

VER 1.1

19

The Deep Power-Down command sequence: CS# goes low→sending Deep Power-Down command→

CS# goes high. The command sequence is shown in Figure 14. CS# must be driven high after the eighth

bit of the command code has been latched in; otherwise the Deep Power-Down (DP) command is not

executed. As soon as CS# is driven high, it requires a delay of tDP before the supply current is reduced to

ICC2 and the Deep Pow- er-Down Mode is entered. Any Deep Power-Down (DP) command, while an

Erase, Program or Write cycle is in progress, is rejected without having any effects on the cycle that is in

progress.

Release from Deep Power-Down and Read Device ID (RDI) (ABH)

The Release from Power-Down and Read/Device ID command 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 Figure15. 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

Figure16. The Device ID value for the ACE25AB400G 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 Figure16, 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.

Figure14. Deep Power-Down Sequence Diagram