AT45D021

5

RESET: A low state on the reset pin (RESET) will terminate

the operation in progress and reset the internal state

machine to an idle state. The device will remain in the reset

condition as long as a low level is present on the RESET

pin. Normal operation can resume once the RESET pin is

brought back to a high level.

The device also incorporates an internal power-on reset

circuit; therefore, there are no restrictions on the RESET

pin during power-on sequences.

READY/BUSY: This open drain output pin will be driven

low when the device is busy in an internally self-timed oper-

ation. This pin, which is normally in a high state (through an

external pull-up resistor), will be pulled low during program-

ming operations, compare operations, and during page-to-

buffer transfers.

The busy status indicates that the Flash memory array and

one of the buffers cannot be accessed; read and write

operations to the other buffer can still be performed.

Power On/Reset State

When power is first applied to the device, or when recover-

ing from a reset condition, the device will default to SPI

mode 3. In addition, the SO pin will be in a high impedance

state, and a high to low stransition on the CS pin will be

required to start a valid instruction. The SPI mode will be

automatically selected on every falling edge of CS by sam-

pling the inactive clock state.

Note:

ational mode is started.

Absolute Maximum Ratings*

Temperature Under Bias ................................ -55

°C to +125°C

*NOTICE:

Stresses beyond those listed under “Absolute

Maximum Ratings” may cause permanent dam-

age to the device. This is a stress rating only and

functional operation of the device at these or any

other conditions beyond those indicated in the

operational sections of this specification is not

implied. Exposure to absolute maximum rating

conditions for extended periods may affect device

reliability.

Storage Temperature ..................................... -65

°C to +150°C

All Input Voltages

(including NC Pins)

with Respect to Ground ...................................-0.6V to +6.25V

All Output Voltages

with Respect to Ground .............................-0.6V to V

DC and AC Operating Range

AT45D021

Operating Temperature (Case)

Com.

0

°C to 70°C

Ind.

-40

°C to 85°C

V

(1)

4.5V to 5.5V