Features

– Internal Address and Data Latches for 64 Bytes

– Internal Control Timer

– Page Write Cycle Time: 10 ms Maximum

– 1- to 64-byte Page Write Operation

– 15 mA Active Current

–20 µA CMOS Standby Current

– Endurance: 10,000 Cycles

– Data Retention: 10 Years

1.

Description

The AT28BV256 is a high-performance electrically erasable and programmable read-

only memory. Its 256K of memory is organized as 32,768 words by 8 bits. Manufac-

tured with Atmel’s advanced nonvolatile CMOS technology, the device offers access

times to 200 ns with power dissipation of just 54 mW. When the device is deselected,

the CMOS standby current is less than 200 µA.

The AT28BV256 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. Following the initiation of a write cycle, the device will automatically write

the latched data using an internal control timer. The end of a write cycle can be

detected by Data polling of I/O7. Once the end of a write cycle has been detected a

new access for a read or write can begin.

Atmel’s AT28BV256 has additional features to ensure high quality and manufactura-

bility. The device utilizes internal error correction for extended endurance and

improved data retention characteristics. An optional software data protection mecha-

nism is available to guard against inadvertent writes. The device also includes an

extra 64 bytes of EEPROM for device identification or tracking.

256K (32K x 8)

Battery-Voltage

Parallel

EEPROMs

AT28BV256

0273K–PEEPR–2/09