DS2502-E48 Maxim, DS2502-E48 Datasheet - Page 3

• Manufacturer Part Number: DS2502-E48
• Description: The DS2502-E48 is a variant of the DS2502 1024-bit add-only memory
• Manufacturer: Maxim

DS2502-E48
The four bytes at memory addresses 01h to 04h contain the UniqueWare Project ID 00001129h. The two
bytes at addresses 0Bh and 0Ch are 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
16
15
2
according to the standardized CRC16 polynomial function X
+ X
+ X
+ 1. For more details on
generating CRC values including examples in both hardware and software, 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-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-E48.
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