ACE25C200

2MB Serial Flash Memory

VER 1.2

21

Figure 18 Deep power-down instruction

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, or obtain the devices electronic identification (ID)

number.

To release the device from the power-down state, the instruction is issued by driving the CS# pin low,

shifting t

he instruction code “ABh” and driving CS# high as shown in Figure 19. Release from

power-

down will take the time duration of tRES1 (See “12.6 AC Electrical Characteristics”) before the

device will resume normal operation and other instructions 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 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 19. The Device ID value for the ACE25C200 is listed in Table 3 Manufacturer and

Device Identification table. The Device ID can be read continuously. The instruction is completed by

driving CS# high.

When used to release the device from the power-down state and obtain the Device ID, the

instruction is the same as previously described, and shown in Figure 20, except that after C S# is

After this time duration the device will resume normal operation and other instructions will be

accepted. If the Release from Power-down / Device ID instruction is issued while an Erase, Program

or Write cycle is in process (when WIP equals 1) the instruction is ignored and will not have any

effects on the current cycle.