OVERVIEW

The block diagram in Figure 1 shows the relationships between the major control and memory sections of the DS2505. The DS2505 has three main data components: 1) 64-bit lasered ROM, 2) 16384-bits EPROM Data Memory, and 3) 704 bits EPROM Status Memory.

FEATURES

16384 bits 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 +48-bit serial number + 8-bit CRC tester) assures absolute traceability because no two parts are alike

Built-in multidrop controller ensures compatibility with other 1-Wire?Net products

EPROM partitioned intosixty-four 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

Architecture allows software to patch data by superseding an old page in favor of a newly programmed page

Reduces control, address, data, power, and programming signals to a single data pin

Directly connects to a single port pin of a microprocessor and communicates at up to 16.3 kbits per second

8-bit family code specifies DS2505 communications requirements to reader

Presence detector acknowledges when the reader first applies voltage

Low cost TO-92 or 6-pin TSOC surface mount package

Reads over a wide voltage range of 2.8V to 6.0V from -40°C to +85°C; programs at 11.5V to 12.0V from -40°C to +50°C