SR176_07 Datasheet, PDF (12/35 Pages) STMicroelectronics – 13.56 MHz, 176-bit short range contactless user EEPROM with 64-bit Unique ID

Memory mapping
4
Memory mapping
SR176
The SR176 is organized as 16 blocks of 16 bits, as shown in Figure 12.
The first four blocks, from location 0 to 3, are used to store read-only data. They store the
64-bit UID. This value cannot be modified.
Blocks from locations 4 to 14 offer a 176-bit EEPROM user area in which the application can
store its data values. Block 15 contains the OTP LOCK_REG and the programmed Chip_ID.
The PROTECT_BLOCK command is used to lock write access to blocks 4 to 15 in groups of
two blocks.
The GET_PROTECTION command gives the status of the protection of blocks 4 to 15.
Figure 12. SR176 memory mapping
Block MSb
Address _b15
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16-bit block
b8 b7
UID0
UID1
UID2
UID3
User Area
User Area
User Area
User Area
User Area
User Area
User Area
User Area
User Area
User Area
User Area
OTP LOCK_REG
Reserved
LSb
Description
b0
64-bit UID
ROM
Lockable EEPROM
Lockable EEPROM
Lockable EEPROM
Lockable EEPROM
Lockable EEPROM
Chip_ID
Lockable EEPROM
ai07699
4.1
Device identification
The SR176 has a 64-bit Unique Identifier (UID) which is written by STMicroelectronics
during the manufacturing process. The UID is unique for each tag and cannot be altered. It
is stored in a Read Only Memory area (ROM). In the SR176, the UID is stored in the first
four blocks of the memory in blocks 0 to 3.
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