AT28C64B

2

The AT28C64B is accessed like a Static RAM for the read

or write cycle without the need for external components.

The device contains a 64-byte page register to allow writing

of up to 64 bytes simultaneously. During a write cycle, the

addresses and 1 to 64 bytes of data are internally latched,

freeing the address and data bus for other operations. Fol-

lowing the initiation of a write cycle, the device will automat-

ically write the latched data using an internal control timer.

The end of a write cycle can be detected by DATA POLL-

ING of I/O

detected, a new access for a read or write can begin.

Atmel’s AT28C64B has additional features to ensure high

quality and manufacturability. The device utilizes internal

error correction for extended endurance and improved data

retention characteristics. An optional software data protec-

tion mechanism is available to guard against inadvertent

writes. The device also includes an extra 64 bytes of

EEPROM for device identification or tracking.

Block Diagram

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

Voltage on OE and A9

with Respect to Ground ...................................-0.6V to +13.5V