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040201

FEATURES

1128 bits of 5V EEPROM memory parti-

tioned into four pages of 256 bits, a 64-bit

write-only secret and up to 5 general purpose

read/write registers

On-chip 512-bit SHA-1 engine to compute

160-bit

Message

Authentication

Codes

(MAC) and to generate secrets

Write access requires knowledge of the secret

and the capability of computing and transmit-

ting a 160-bit MAC as authorization

Secret and data memory can be write-pro-

tected (all or page 0 only) or put in EPROM-

emulation mode (“write to 0”, page 1)

Unique, factory-lasered and tested 64-bit reg-

istration number assures absolute traceability

because no two parts are alike

Built-in multidrop controller ensures compati-

bility with other 1-Wire net products

Reduces control, address, data and power to a

single data pin

Directly connects to a single port pin of a mi-

croprocessor and communicates at up to 16.3k

bits per second

Overdrive mode boosts communication speed

to 142k bits per second

Low cost 6-lead TSOC surface mount pack-

age, or solder-bumped Flipchip package

Reads and writes over a wide voltage range of

2.8V to 5.25V from -40°C to +85°C

PIN ASSIGNMENT

TSOC (150mil)

1-WIRE

GND

NC

1

2

3

6

5

4

NC

NC

NC

top view

side view

top view

specifications of packages.

ORDERING INFORMATION

DS2432P

6-lead TSOC package

DS2432P/T&R

Tape & Reel DS2432P

DS2432X

Flipchip package, tape & reel

DESCRIPTION

The DS2432 combines 1024 bits of EEPROM, a 64-bit secret, an 8-byte register/control page with up to 5

user read/write bytes, a 512-bit SHA-1 engine and a fully-featured 1-Wire interface in a single chip. Each

DS2432 has its own 64-bit ROM registration number that is factory lasered into the chip to provide a

guaranteed unique identity for absolute traceability. Data is transferred serially via the 1-Wire protocol,

which requires only a single data lead and a ground return. The DS2432 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 will transfer the data to its final memory location,

provided that the DS2432 receives a matching 160-Bit MAC. The computation of the MAC involves the

secret and additional data stored in the DS2432 including the device’s registration number. Only a new

secret can be loaded without providing a MAC. The SHA-1 engine can also be activated to compute

DS2432

1k-Bit Protected 1-Wire

™

EEPROM with SHA-1 Engine

www.dalsemi.com

Preliminary