DS2502-E48 MAXIM | Alldatasheet
Document overview
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Technical content
19-5071; 12/09 DS2502-E48 48-Bit Node Address Chip 1 of 4 Note: Some revisions of this device may incorporate deviations from published specifications known as errata. Multiple revisions of any device may be simultaneously available through various sales channels. For information about device errata, click here: www.maxim-ic.com/errata. www.maxim-ic.com
FEATURES
Factory programmed 48-bit node address chip with 768 bits user-programmable OTP- EPROM communicates with the economy of one signal plus ground Provides valid MAC-48/EUI-48 Ethernet address Unique, factory lasered and tested 64-bit registration number assures absolute traceability because no two parts are alike Built-in multidrop controller ensures compatibility with other 1-Wire ® products 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 Directly connects to a single port pin of a microprocessor and communicates at up to 16.3kbps Presence detector acknowledges when reader first applies voltage Low cost TO-92 or TSOC surface mount packages 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 PIN CONFIGURATION TO-92 BOTTOM VIEW TSOC PACKAGE TOP VIEW
ORDERING INFORMATION
DS2502-E48+ -40°C to +85°C 3 TO-92 DS2502P-E48+ -40°C to +85°C 6 TSOC DS2502P-E48+T&R -40°C to +85°C 6 TSOC + Denotes a lead(Pb)-free/RoHS-compliant package. T&R = Tape and reel. 1-Wire is a registered trademark of Maxim Integrated Products, Inc.
DESCRIPTION
The DS2502-E48 is a variant of the DS2502 1024-bit ad d-only memory. It differs from the standard DS2502 in its custom ROM family code 89h, and the UniqueWare Identifier 5E7h in place of the upper 12 bits of the standard ROM serializ ation field. Otherwise, the electrical and logical behavior is identical to that of the DS2502. For technical details please refer to the DS2502 data sheet.
APIs can be found in the 1-Wire Software Development Kits. Figure 1. NODE ADDRESS CHIP DATA STRUCTURE
19 BYTES
1 BYTE
and the IEEE-assigned 24-bit company ID value 006035h. An inverted 16-bit CRC ends the data record. byte and bit representations are illustrated in Figure 2. Figure 2. SAMPLE NODE ADDRESS VALUE address. Including the length byte and the inverted CRC, the complete set of data is shown in Figure 3. Figure 3. PHYSICAL ADDRESS AND DATA MAPPING INSIDE THE DEVICE
The four bytes at memory addr esses 01h to 04h contain the Uni queWare Project ID 00001129h. The two bytes at addresses 0Bh and 0Ch ar e the inverted 16-bit CRC over the length byte, Project ID and node address value. The least significant byte of the CRC is stored at address 0Bh. This CRC is generated according to the standardized CRC16 polynomial function X 16 + X 15 + X 2 + 1. For more details on generating CRC values including exam ples in both hardware and soft ware, see Application Note 27, Understanding and Using Cyclic Redundancy Checks with Maxim iButton Products. The contents of the memory address range 0Dh to 1Fh is FFh. These cells cannot be altered since the whole memory page is write-pro tected. The memory range from 20h to 7Fh, however, is user- programmable. It can be write-protected by programming the corresponding write-protect bit in the status memory of the DS2502-E48.
REVISION HISTORY
Changed the Ordering Information to lead free. 1 Included an explanation of “Default Data Structure” above Figure 1. 2 Emphasized that the 16-bit CRC is inverted. 2 Deleted paragraph on how to set up a UniqueWare project. 2 Inserted actual CRC value to Figure 3. 2 Reformatted Figures 1 to 3. 2 Corrected notation of hexadecimal numbers from H to h. 1, 2, 3