512Mb, Multiple I/O Serial Flash Memory
Power-Up and Power-Down
Power-Up and Power-Down
Power-Up and Power-Down Requirements
At power-up and power-down, the device must not be selected; that is, S# must follow
the voltage applied on VCC until VCC reaches the correct values: VCC,min at power-up and
VSS at power-down.
To avoid data corruption and inadvertent WRITE operations during power-up, a power-
on reset circuit is included. The logic inside the device is held to RESET while VCC is less
than the power-on reset threshold voltage shown here; all operations are disabled, and
the device does not respond to any instruction. During a standard power-up phase, the
device ignores all commands except READ STATUS REGISTER and READ FLAG STATUS
REGISTER. These operations can be used to check the memory internal state. After
power-up, the device is in standby power mode; the write enable latch bit is reset; the
write in progress bit is reset; and the lock registers are configured as: (write lock bit, lock
down bit) = (0,0).
Normal precautions must be taken for supply line decoupling to stabilize the VCC sup-
ply. Each device in a system should have the VCC line decoupled by a suitable capacitor
(typically 100nF) close to the package pins. At power-down, when VCC drops from the
operating voltage to below the power-on-reset threshold voltage shown here, all opera-
tions are disabled and the device does not respond to any command.
When the operation is in progress, the program or erase controller bit of the status reg-
ister is set to 0. To obtain the operation status, the flag status register must be polled
twice, with S# toggled twice in between commands. When the operation completes, the
program or erase controller bit is cleared to 1. The cycle is complete after the flag status
register outputs the program or erase controller bit to 1 both times.
Note: If power-down occurs while a WRITE, PROGRAM, or ERASE cycle is in progress,
data corruption may result.
VPPH must be applied only when VCC is stable and in the VCC,min to VCC,max voltage
range.
Figure 38: Power-Up Timing
VCC
VCC,max
Chip selection not allowed
tVTW = tVTR
Device fully accessible
VCC,min
VWI
t
Chip reset
VTP
Polling allowed
SPI protocol
Starting protocol defined by NVCR
WIP = 1
WEL = 0
WIP = 0
WEL = 0
Time
PDF: 09005aef84752721
n25q_512mb_1ce_3V_65nm.pdf - Rev. O 05/13 EN
Micron Technology, Inc. reserves the right to change products or specifications without notice.
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