sri4k STMicroelectronics, sri4k Datasheet - Page 15

• Manufacturer Part Number: sri4k
• Description: 13.56 Mhz Short-range Contactless Memory Chip With 4096-bit Eeprom And Anticollision Functions
• Manufacturer: STMicroelectronics

SRI4K
4.1
Resettable OTP area
In 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 SRI4K detects a Reload command. The Reload command is implemented
through a specific update of the
“Section 4.2: 32-bit binary
Previous data stored in block
Data to be written
New data stored in block
Block
Address
0
1
2
3
4
for examples of the result of the WRITE_BLOCK command in the resettable OTP
MSb
b31
b31
counters” for details).
b24 b23
1
1
1
...
...
...
32
-bit binary counter located at block address 6 (see
1
1
1
32-bit Boolean Area
32-bit Boolean Area
32-bit Boolean Area
32-bit Boolean Area
32-bit Boolean Area
1
0
0
32-bit Block
b16 b15
0
0
0
1
1
1
0
0
0
1
1
1
b8 b7
1
1
1
Figure 12
1
0
0
LSb
b0
1
0
0
for a map of the
Memory mapping
1
1
1
Figure 13
Resettable
OTP Bit
Description
0
1
0
1
1
1
ai07657
ai07658
and
15/49
1
1
1
b0