DS1961S-F3

DS1961S-F3 Datasheet


DS1961S

Part Datasheet
DS1961S-F3 DS1961S-F3 DS1961S-F3 (pdf)
Related Parts Information
DS1961S-F5+ DS1961S-F5+ DS1961S-F5+
DS1961S-F3+ DS1961S-F3+ DS1961S-F3+
DS1961S-F3# DS1961S-F3# DS1961S-F3#
PDF Datasheet Preview
DS1961S
1kb Protected EEPROM iButton With SHA-1 Engine

SPECIAL FEATURES
§ 1128 Bits of 5V EEPROM Memory Partitioned into Four Pages of 256 Bits, a 64-

Bit Write-Only Secret, and up to Five

General-Purpose Read/Write Registers § Write Access Requires Knowledge of the

Secret and the Capability of Computing and

Transmitting a 160-Bit MAC Message

Authentication Code as Authorization § Secret and Data Memory can be Write-

Protected All or Page 0 Only or put in

EPROM-Emulation Mode “Write to 0”, Page
1 § On-Chip, 512-Bit SHA-1 Engine to Compute
160-Bit MACs and Generate Secrets § Reads and Writes Over a Wide 2.8V to 5.25V

Voltage Range from -40°C to +85°C § Communicates to Host with a Single Digital

Signal at 14.1kbps using Protocol § On-Chip, 16-Bit Cyclic Redundancy Check

CRC Generator for Safeguarding Data

Transfers § Overdrive Mode Boosts Communication

Speed to 125kbps § Operating Temperature Range from -40°C to
+85°C § Minimum 10 Years of Data Retention at
+85°C
§ Button Shape is Self-Aligning with CupShaped 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, Groups A, B, C, and D Locations Application Pending

F5 MicroCan
1993

YYWW REGISTERED RR

IO GND

F3 MicroCan

COMMON iButton FEATURES
§ Unique, Factory-Lasered and Tested 64-Bit Registration Number 8-Bit Family Code + 48-Bit Serial Number + 8-Bit CRC Tester Assures Absolute Traceability Because No Two Parts are Alike
§ Multidrop Controller for 1-Wire Net § Digital Identification and Information by

Momentary Contact § Chip-Based Data Carrier Compactly Stores

Information § Data can be Accessed While Affixed to

Object
1993

YYWW REGISTERED RR

All dimensions are shown in millimeters.
iButton, 1-Wire, and MicroCan are registered trademarks of Dallas Semiconductor.
1 of 36
ORDERING INFORMATION

DS1961S-F5

F5 iButton

DS1961S-F3

F3 iButton

DS1961S

EXAMPLES OF ACCESSORIES

DS1963S

SHA Coprocessor and Button

DS9096P

Self-Stick Adhesive Pad

DS9101

Multipurpose Clip

DS9093RA Mounting Lock Ring

DS9093A

Snap-In Fob

DS9092
iButton Probe
iButton DESCRIPTION

The DS1961S combines 1024 bits of EEPROM, a 64-bit secret, an 8-byte register/control page with up to five user-read/write bytes, a 512-bit SHA-1 engine, and a fully featured 1-Wire interface in a rugged iButton. Data is transferred serially through the 1-Wire protocol, which requires only a single data lead and a ground return. The DS1961S has an additional memory area called the scratchpad that acts as a buffer when writing to the main memory, the register page, or when installing a new secret. Data is first written to the scratchpad from where it can be read back. After the data has been verified, a copy scratchpad command transfers the data to its final memory location, provided that the DS1961S receives a matching 160-bit MAC. The computation of the MAC involves the secret and additional data stored in the DS1961S including the device’s identity register. Only a new secret can be loaded without providing a MAC. The SHA-1 engine can also be activated to compute 160-bit MACs when reading a memory page or to compute a new secret, instead of loading it.

The DS1961S understands a unique command "Refresh Scratchpad." Proper use of a refresh sequence after a copy scratchpad operation reduces the number of weak bit failures in a touch environment see the Writing with Verification section . The refresh sequence also provides a means to restore functionality in a device with bits in a weak state.

Each DS1961S has its own 64-bit ROM registration number that is factory lasered into the chip to provide a guaranteed unique identity for absolute traceability. The durable stainless-steel package is highly resistant to environmental hazards such as dirt, moisture, and shock. Its compact coin-shaped profile is self-aligning with mating receptacles, allowing the DS1961S to be easily used by human operators. Accessories permit the DS1961S to be mounted on almost any surface including plastic key fobs and photo-ID badges.

The DS1961S can be used for different purposes such as secure access control, user/product authentication, after-market management of consumables, and as monetary tokens in electronic payment systems. As carrier of electronic cash eCash , the DS1961S can store up to three monetary files or "purses" of a single service provider, which make the device well suited for company-sized single-secret applications such as cafeteria, copy machines, and access control at entertainment parks or private clubs. For increased security or if the processing power of the host microcontroller is insufficient, a DS1963S can be used as secure coprocessor to verify MACs generated by the DS1961S or to compute MACs needed for writing to the DS1961S.

OVERVIEW

The block diagram in Figure 1 shows the relationships between the major control and memory sections of the DS1961S. The DS1961S has five main data components 1 64-bit lasered ROM, 2 64-bit scratchpad, 3 four 32-byte pages of EEPROM, 4 64-bit register page, 5 64-bit secrets memory, and 6 a 512-bit
2 of 36

DS1961S

SHA-1 Secure Hash Algorithm engine. The hierarchical structure of the 1-Wire protocol is shown in Figure The bus master must first provide one of the seven ROM function commands, 1 Read ROM, 2 Match ROM, 3 Search ROM, 4 Skip ROM, 5 Resume Communication, 6 Overdrive-Skip ROM, or 7 Overdrive-Match ROM. Upon completion of an overdrive ROM command byte executed at standard speed, the device enters overdrive mode where all subsequent communication occurs at a higher speed. The protocol required for these ROM function commands is described in Figure After a ROM function command is successfully executed, the memory functions become accessible and the master can provide any one of the eight memory and SHA function commands. The protocol for these memory and SHA function commands is described in Figure All data is read and written LSB first.

Figure DS1961S BLOCK DIAGRAM

Parasite Power
1-Wire Net
1-Wire Function Control
64-bit Lasered ROM

Memory and SHA Function Control Unit

CRC16 Generator

Data Memory 4 Pages of
256 bits Each
512-bit Secure Hash

Algorithm Engine
64-bit Scratchpad

Register Page 64-bit
More datasheets: DC-450-130-CI | DC-800-130-CI | DC-750-CI | DC-450-CI | 529-02-38R01 | 87614040 | 87614340 | 87614440 | DS1961S-F5+ | DS1961S-F3+


Notice: we do not provide any warranties that information, datasheets, application notes, circuit diagrams, or software stored on this website are up-to-date or error free. The archived DS1961S-F3 Datasheet file may be downloaded here without warranties.

Datasheet ID: DS1961S-F3 508390