DS1422

• 1024bits Electrically Programmable Read Only Memory (EPROM) partitioned into four 256bit pages for randomly     accessing packetized data records
• Each memory page can be permanently writeprotected to prevent tampering
• Device is an "add only" memory where additional data can be programmed into EPROM without disturbing    existing data
• Architecture allows software to patch data by superseding an old page in favor of a newly programmed page
• Reads over a wide voltage range of 2.8V to 6.0V from 40°C to +85°C; programs at 11.5V ± 0.5V from 40°C     to +85°C

The DS1422 UniqueWare Button is an add only alternative to the static RAM based DS1425 and DS1427 Buttons. The DS1422 consists of a factorylasered 64 bit identification number plus 1Kbit of EPROM, which is userprogrammable. The power to program and read the DS1422 is derived entirely from the 1Wire communication line. Data is transferred serially via the 1Wire protocol. The entire device can be programmed and then writeprotected if desired. Alternatively, the part may be programmed multiple times with new data being appended to, but not overwriting, existing data with each subsequent programming of the device. Note: Individual bits can be changed only from a logical 1 to a logical 0, never from a logical 0 to a logical 1. A provision is also included for indicating that a certain page or pages of data are no longer valid and have been replaced with new or updated data that is now residing at an alternate page address. This page address redirection allows software to patch data and enhance the flexibility of the device as a standalone database.

The DS1422 can be programmed with unchangeable information (perhaps a division, location or family code of the applications origin) and used to maintain update and version control information, tied to a unique identification number. Audibility becomes a snap by reading the history of the software's distribution, customized for each installation of your software.