DS2502(3)

NAME
DS2502 - Add-Only Memory (1 kBit)

DS2502-E48, DS2502-UNW
    - 48-bit Node Address Chip, UniqueWare Add-Only Memory (1 kBit)

DS1982, DS1982U
    - Add-Only iButton (1 kBit), UniqueWare iButton (1 kBit)

SYNOPSIS
EPROM add-only memory.

09 [.]XXXXXXXXXXXX[XX][/[ memory | pages/page.[0-3|ALL] | ]]

89 [.]XXXXXXXXXXXX[XX][/[ mac_e | mac_fw | memory | pages/page.[0-3|ALL] | project | ]]

FAMILY CODE

09  DS2502 DS1982

89  DS2502-UNW DS2502-E48 DS1982U

SPECIAL PROPERTIES

  mac_e mac_fw
read-only, binary
64 bit or 80 bit media access control number. Unique, and unrelated to the 1-wire address. It is apparently used for ethernet or FireWire addressing, respectively.

  memory
read-write, binary
128 bytes of memory. Initially all bits are set to 1. Writing zero permanently alters the memory.

  pages/page.0 ... pages/page.3 pages/page.ALL
read-write, yes-no
Memory is split into 4 pages of 32 bytes each. ALL is an aggregate of the pages. Each page is accessed sequentially.

  project
read-only, binary
32 bit project id. Constant 0x0000 for ethernet and 0x00001128 for firewire. See Datasheets.

STANDARD PROPERTIES

ALARMS
None.

DESCRIPTION

  DS2502 DS1982
The DS2502 (3) is used for write-once incremental storage. It's main advantage is for audit trails (i.e. a digital purse).

The DS2502-E48 and DS2502-UNW are some of the UniqueWare class of devices. Some of the memory was preprogramed at the factory. See the datasheet for specifics. The DS2502 , DS2505 , and DS2506 differ in their function by the amount of on-board memory they possess. (The internal protocols are slightly different, but the OWFS system handles this automatically.

ADDRESSING

DATASHEET
http://pdfserv.maxim-ic.com/en/ds/DS2502.pdf
http://pdfserv.maxim-ic.com/en/ds/DS2502-E48.pdf
http://pdfserv.maxim-ic.com/en/ds/DS2502-UNW-DS2506S-UNW.pdf
http://pdfserv.maxim-ic.com/en/ds/DS1982-F3-DS1982-F5.pdf
http://pdfserv.maxim-ic.com/en/ds/DS1982U-DS1986U.pdf

SEE ALSO

AVAILABILITY
http://www.owfs.org

AUTHOR
Paul Alfille (paul.alfille@gmail.com)