1 of 2 102099 features ieee-approved factory programmed 64-bit node address chip (eui-64) with 768 bits user-programmable otp-eprom communicates with the economy of one signal plus ground meets the node identification requirements of ieee standard 1394-1995 ( firewire ? ) unique, factory- lasered and tested 64-bit registration number (8-bit family code 89h + 36-bit serial number + 12-bit uniqueware identifier 5e7h + 8-bit crc tester) assures absolute traceability because no two parts are alike built-in multidrop controller ensures compatibility with other microlan 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 16.3k bits per second 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 -40c to +85c; programs at 11.5v to 12.0v from -40c to +50c 3 2 1 pin assignment ordering information DS2502-E64 to-92 package ds2502p-e64 6-pin tsoc package firewire tm is a trademark of apple computer, inc. global indentifier description the DS2502-E64 is a variant of the ds2502 1024-bit add-only memory. it differs from the standard ds2502 in its custom rom family code 89h, and the uniqueware identifier 5e7 in place of the upper 12 bits of the standard rom serialization field. otherwise, the electrical and logical behavior is identical to that of the ds2502. for technical details please refer to the ds2502 data sheet. the first 32 bytes of the DS2502-E64?s eprom memory contain a globally unique 64-bit node address (eui-64) and are write- protected. the data structure follows the conventions of uniqueware devices using default data structure (figure 1). DS2502-E64 ieee eui-64 node address chip www.dalsemi.com side view see mech. drawing section top view the dot marks pin 1 tsoc package e 6 4 2 5 0 2 yyww data nc nc nc nc gnd yyww = date code rr = die revision code cccccc = country code bottom view to-92 DS2502-E64 yywwrr cccccc gnd data nc 2 3 1
DS2502-E64 2 of 2 102099 the data record starts with a length byte (0ch) and the 4-byte uniqueware project id 00001128h. the next eight bytes contain the eui-64 global identifier (node address) which consists of an incrementing 40-bit extension identifier and the ieee-assigned 24-bit company id value 006035h. a 16-bit crc ends the data record. the remaining bytes of the 32-byte memory page remain unprogrammed. neither the 40? bit extension identifier nor the 24-bit company id are related to the 64-bit rom registration number, which is distinct from the ieee standard 1394-1995 node address. the rom registration number is used to provide a unique address to access the DS2502-E64 when multidropped on a 1-wire tm bus. eui-64 node address chip data structure figure 1 (unused) crc16 company id value extension id value project id length msb lsb msb lsb msb lsb msb lsb 17 bytes ffh 2 bytes 3 bytes constant 006035h 5 bytes serialization 4 bytes constant 00001128h 1 byte 0ch high address low address example assume that a manufacturer?s company id value is 006035 16 and the 40-bit extension identifier is 234567abcd 16 . the eui-64 value generated from these two numbers is 006035234567abcd 16 , whose byte and bit representations are illustrated in figure 2. this information is stored in the DS2502-E64 as 64-bit number with the least significant byte at the lower address. including the length byte and the crc, the complete set of data is shown in figure 3. sample eui-64 value figure 2 most significant byte least significant byte 00 60 35 23 45 67 ab cd hex 0000 0000 0110 0000 0011 0101 0010 0011 0100 0101 0110 0111 1010 1011 1100 1101 binary most significant bit least significant bit physical address and data mapping inside the device figure 3 address 0e 0d 0c 0b 0a 09 08 07 06 05 04 03 02 01 00 data xx xx 00 60 35 23 45 67 ab cd 00 00 11 28 0c xx xx = crc16, value depends on actual data the four bytes at memory addresses 01 to 04 contain the uniqueware project id 00001128 16 . the two bytes at addresses 0dh and 0eh are the 16-bit crc over the length byte, project id and eui-64 value. the least significant byte of the crc is stored at address 0d. 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 examples in both hardware and software, see the ?book of ds19xx i button standards? or application note 27. the contents of the memory address range 0fh to 1fh is ffh. these cells cannot be altered since the whole memory page is write-protected. 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-E64.
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