19-5070; Rev 12/09
DS1982U/DS1985U
UniqueWare™ iButton®
SPECIAL FEATURES
1024 bits or 16Kb Electrically Programmable
Read Only Memory (EPROM)
communicates with the economy of one
signal plus ground
Unique, factory lasered and tested 64-bit
registration number (8-bit family code, 3-bit
serialization, 12-bit UniqueWare Identifier
5E7h, 8-bit CRC tester) assures absolute
traceability because no two parts are alike
EPROM partitioned into 256-bit pages for
randomly accessing packetized data records
Each memory page can be permanently
write-protected to prevent tampering
Device is an “add only” memory where
additional data can be programmed into
EPROM without disturbing existing data
Reduces control, address, data, power and
programming signals to a single pin
8-bit family code specifies device
communications requirements to reader
Presence detector acknowledges when reader
first applies voltage
Reads over a wide voltage range of 2.8V to
6.0V from -40°C to +85°C
COMMON iButton FEATURES
Multidrop controller for 1-Wire network
Digital identification and information by
momentary contact
Chip-based data carrier compactly stores
information
Data can be accessed while affixed to object
Economically communicates to bus master
with a single digital signal at 16.3kbps
Standard 16mm diameter and 1-Wire®
protocol ensure compatibility with iButton®
family
Button shape is self-aligning with cup-
shaped probes
Durable stainless steel case engraved with
registration number withstands harsh
environments
Easily affixed with self-stick adhesive
backing, latched by its flange, or locked with
a ring pressed onto its rim
Presence detector acknowledges when reader
first applies voltage
Meets UL#913 (4th edit.); Intrinsically Safe
Apparatus, Approved under Entity Concept
for use in Class I, Division 1, Group A, B, C
and D Locations (application pending)
DESCRIPTION
UniqueWare iButtons are factory-programmed versions of the DS1982 (1024 bit) and the DS1985 (16Kb)
Add-Only iButtons, respectively. They differ from the regular devices in their custom ROM family codes
(see the Ordering Information) and the UniqueWare Identifier 5E7h in place of the upper 12 bits of the
standard serialization field. For technical details on the devices, refer to the DS1982 and DS1985 data
sheets.
UniqueWare Add-Only iButtons are only available preprogrammed with customer-specific and write-
protected data. UniqueWare data fills at least one but no more than the first two pages of a device,
depending on the length of the customer-supplied data.
UniqueWare devices are only available to existing customers. New data patterns are no longer accepted.
The minimum order quantity (MOQ) is 34,000 pieces with higher quantities available in multiples of
17,000 pieces. UniqueWare iButtons can only be purchased in bulk form, delivered in bags. The shipment
quantity can be plus or minus 10% of the order quantity. Only the quantity shipped will be billed.
UniqueWare is a trademark of Maxim Integrated Products, Inc.
iButton and 1-Wire are registered trademarks of Maxim Integrated Products, Inc.
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DS1982U/DS1985U
Sample UniqueWare Data Structures
SAMPLE 1: ETHERNET NODE ADDRESS
Figure 1a
CRC16
Company ID Value Extension ID Value
Project ID
Length
MSB
LSB MSB
LSB MSB
LSB MSB
LSB
19 bytes
2 bytes
3 bytes constant
3 bytes serialization
4 bytes
1 byte
FFh
assigned by IEEE
constant
0Ah
high address
low address
(unused)
PHYSICAL ADDRESS AND DATA MAPPING Figure 1b
0C
0B
0A
09
08
07
06
05
04
03
02
Address
xx
xx
ch
cm
cl
hh
mm
ll
00
00
pp
Data
xx xx = inverted CRC16, value depends on actual data
ch cm cl = high, medium and low byte of the IEEE assigned “Company ID”
hh mm ll = high, medium and low byte of the “Extension ID” or serialization
pp pp = Project ID assigned by Maxim
01
pp
00
0A
SAMPLE 2: EUI-64 FireWire
®
NODE ADDRESS
Figure 2a
CRC16
Company ID Value Extension ID Value
Project ID
Length
MSB
LSB MSB
LSB MSB
LSB MSB
LSB
17 bytes
2 bytes
3 bytes constant
5 bytes serialization
4 bytes
1 byte
FFh
assigned by IEEE
constant
0Ch
high address
low address
(unused)
PHYSICAL ADDRESS AND DATA MAPPING
Figure 2b
0E 0D 0C 0B 0A 09
08
07
06
05
04
03
02
01
Address
xx
xx
ch cm
cl
hh hm mm ml
ll
00
00
pp
pp
Data
xx xx = inverted CRC16, value depends on actual data
ch cm cl = high, medium and low byte of the IEEE assigned “Company ID”
hh hm mm ml ll = high, medium and low byte of the “Extension ID” or serialization
pp pp = Project ID assigned by Maxim
00
0C
The examples shown here use the Default Data Structure. This format is also known as UDP (universal
data packet) and is commonly used in 1-Wire APIs. Therefore, if using one of those APIs one can call a
high level function to read and verify the inverted CRC16. The UDP is defined in Application Note 114:
1-Wire File Structure,
and the APIs can be found in the
1-Wire Software Development Kits.
FireWire is a registered trademark of Apple Computer, Inc.
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DS1982U/DS1985U
REVISION HISTORY
REVISION
DATE
Removed the DS1986U.
12/09
Removed instructions on how to set up a UniqueWare project (no new projects).
Added MOQ and shipment quantity information.
Emphasized that the 16-bit CRC is inverted.
Included an explanation of “Default Data Structure.”
Changed notation of hexadecimal numbers from H to h.
DESCRIPTION
Changed the
Ordering Information
to lead(Pb)-free.
PAGES
CHANGED
3
1, 2, 3
1
1
1
2
1, 2, 3
4 of 4
Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are implied. Maxim
reserves the right to change the circuitry and specifications without notice at any time.
M a x i m I n t e g r a t e d P r o d u c t s , 1 2 0 S a n G a b r i e l D r iv e , S u n n y v a le , C A 9 4 0 8 6 4 0 8- 7 3 7 - 7 6 0 0
© 2009 Maxim Integrated Products
Maxim is a registered trademark of Maxim Integrated Products, Inc.
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