M24C01-WBN6P Datasheet, PDF (8/38 Pages) STMicroelectronics – 16 Kbit, 8 Kbit, 4 Kbit, 2 Kbit and 1 Kbit serial I²C bus EEPROM

Signal description
2
Signal description
M24C16, M24C08, M24C04, M24C02, M24C01
2.1
Serial Clock (SCL)
This input signal is used to strobe all data in and out of the device. In applications where this
signal is used by slave devices to synchronize the bus to a slower clock, the bus master
must have an open drain output, and a pull-up resistor can be connected from Serial Clock
(SCL) to V_CC. (Figure 5 indicates how the value of the pull-up resistor can be calculated). In
most applications, though, this method of synchronization is not employed, and so the pull-
up resistor is not necessary, provided that the bus master has a push-pull (rather than open
drain) output.
2.2
Serial Data (SDA)
This bidirectional signal is used to transfer data in or out of the device. It is an open drain
output that may be wire-ORed with other open drain or open collector signals on the bus. A
pull up resistor must be connected from Serial Data (SDA) to V_CC. (Figure 5 indicates how
the value of the pull-up resistor can be calculated).
2.3
2.3.1
Chip Enable (E0, E1, E2)
These input signals are used to set the value that is to be looked for on the least significant
bits of the 7-bit device select code. These inputs must be tied to V_CC or V_SS, to establish the
device select code as shown in Figure 4. When not connected (left floating), Ei inputs are
read as low (0).
Figure 4. Device select code
VCC
VCC
M24Cxx
Ei
M24Cxx
Ei
VSS
VSS
Ai11650
Write Control (WC)
This input signal is useful for protecting the entire contents of the memory from inadvertent
write operations. Write operations are disabled to the entire memory array when Write
Control (WC) is driven High. When unconnected, the signal is internally read as V_IL, and
Write operations are allowed.
When Write Control (WC) is driven High, device select and address bytes are
acknowledged, data bytes are not acknowledged.
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Doc ID 5067 Rev 17