M24C64 datasheet(17/39 Pages) STMICROELECTRONICS

17 / 39 page

M24128, M24C64, M24C32

Device operation

17/39

Figure 9.

Write mode sequences with WC = 0 (data write enabled)

4.9

ECC (error correction code) and write cycling

The M24128 and M24C64 in UFDFPN8 (MLP) 2 × 3 mm package and the M24128 in

WLCSP package offer an ECC (error correction code) logic which compares each 4-byte

word with its six associated EEPROM ECC bits. 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 much 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 word), 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.

All M24C32, M24C64 and M24128 devices are qualified at 1 million (1 000 000) write

cycles; the M24128 and M24C64 in UFDFPN8 (MLP) 2 × 3 mm package and the M24128 in

WLCSP package are qualified (at 1 million write cycles), using a cycling routine that writes

to the device by multiples of 4-byte words.

Byte Write

Dev Select

Byte address

Data in

Page Write

Dev Select

Byte address

Data in 1

Data in 2

AI01106d

Page Write

(cont'd)

WC (cont'd)

Data in N

ACK

R/W

ACK

R/W

ACK

M24C64 Datasheet(PDF) 17 Page - STMicroelectronics