m95128 STMicroelectronics, m95128 Datasheet - Page 23

• Manufacturer Part Number: m95128
• Description: 128 Kbit Serial Spi Bus Eeprom With High Speed Clock
• Manufacturer: STMicroelectronics

M95128, M95128-W, M95128-R
5.6.1
Figure 11. Page Write (WRITE) sequence
1. The most significant address bits (b15, b14) are Don’t Care.
ECC (error correction code) and Write cycling
The M95128 devices offer an ECC (error correction code) logic which compares each 4-byte
word with 6 EEPROM bits of ECC. As a result, if a single bit out of 4 bytes of data happens
to be erroneous during a Read operation, the ECC detects it and replaces it by the correct
value. The read reliability is therefore improved by the use of this feature.
Note however that even if a single byte has to be written, 4 bytes are internally modified
(plus the ECC bits), that is, the addressed byte is cycled together with the three other bytes
making up the word. It is therefore recommended to Write by packets of 4 bytes in order to
benefit from the larger amount of Write cycles.
The maximum number of Write cycles for the M95128 (range 6) device is qualified at 1
Million (1 000 000) Write cycles, using a cycling routine that writes to the device by multiples
of 4-byte packets.
S
C
D
S
C
D
7
32
0
6
33
1
5
34
Data Byte 2
2
4
Instruction
35 36 37 38 39 40 41 42
3
3
4
2
5
1
6
0
7
7
15
8
6
14 13
9 10
5
Data Byte 3
16-Bit Address
4
43
3
44 45 46 47
3
20 21 22 23 24 25 26 27
2
2
1
1
0
0
7
6
6
5
Data Byte N
5
Data Byte 1
4
4
3
3
28 29 30
2
2
1
Instructions
1
0
0
31
AI01796D
23/44