sri512 STMicroelectronics, sri512 Datasheet - Page 15

• Manufacturer Part Number: sri512
• Description: 13.56-mhz Short-range Contactless Memory Chip With 512-bit Eeprom And Anti-collision Functions
• Manufacturer: STMicroelectronics

SRI512
4.1
Resettable OTP area
This area contains five individual 32-bit Boolean Words (see
area). A WRITE_BLOCK command will not erase the previous contents of the block as the
Write cycle is not preceded by an Auto Erase cycle. This feature can be used to reset
selected bits from 1 to 0. All bits previously at 0 remain unchanged. When the 32 bits of a
block are all at 0, the block is empty, and cannot be updated any more. See
Figure 14
area.
Figure 12. Resettable OTP area (addresses 0 to 4)
Figure 13. WRITE_BLOCK update in standard mode (binary format)
The five 32-bit blocks making up the Resettable OTP area can be erased in one go by
adding an Auto Erase cycle to the WRITE_BLOCK command. An Auto Erase cycle is added
each time the SRI512 detects a Reload command. The Reload command is implemented
through a specific update of the 32-bit binary counter located at block address 6 (see
Section 4.2: 32-bit binary counters
Previous data stored in block
Data to be written
New data stored in block
Address
Block
0
1
2
3
4
for examples of the result of the WRITE_BLOCK command in the resettable OTP
MSb
b31
b31
1
1
1
...
...
...
32-bit Boolean Area
32-bit Boolean Area
32-bit Boolean Area
32-bit Boolean Area
32-bit Boolean Area
for details).
1
1
1
b16 b15 b14
32-bit Block
1
0
0
0
0
0
1
1
1
0
0
0
b8 b7
1
1
1
Figure 12
1
1
1
1
0
0
LSb
1
0
0
b0
for a map of the
Memory mapping
1
1
1
Figure 13
Resettable
OTP Bit
Description
0
1
0
1
1
1
ai07658
and
ai12381
15/50
1
1
1
b0