m34e02 STMicroelectronics, m34e02 Datasheet - Page 9

• Manufacturer Part Number: m34e02
• Description: 2 Kbit Serial I?c Bus Eeprom With Permanent And Reversible, Software Write Protection
• Manufacturer: STMicroelectronics

M34E02
2
2.1
2.2
2.3
2.4
Signal description
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
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.
Serial Data (SDA)
This bi-directional signal is used to transfer data in or out of the device. It is an open drain
output that may be wire-OR’ed with other open drain or open collector signals on the bus. A
pull up resistor must be connected from Serial Data (SDA) to V
the value of the pull-up resistor can be calculated).
Chip Enable (E0, E1, E2)
These input signals are used to set the value that is to be looked for on the three least
significant bits (b3, b2, b1) of the 7-bit Device Select Code. In the end application, E0, E1
and E2 must be directly (not through a pull-up or pull-down resistor) connected to V
V
pull-down circuitry makes (E0,E1,E2) = (0,0,0).
The E0 input is used to detect the V
Figure 3.
Write Control (WC)
This input signal is provided for protecting the contents of the whole memory from
inadvertent write operations. Write Control (WC) is used to enable (when driven Low) or
disable (when driven High) write instructions to the entire memory area or to the Protection
Register.
When Write Control (WC) is tied Low or left unconnected, the write protection of the first half
of the memory is determined by the status of the Protection Register.
SS
to establish the Device Select Code. When these inputs are not connected, an internal
CC
Device Select Code
.
(Figure 4
indicates how the value of the pull-up resistor can be calculated). In
E i
HV
M34E02
V CC
V SS
voltage, when decoding an SWP or CWP instruction.
E i
M34E02
V CC
V SS
Ai12301
CC
.
(Figure 4
Signal description
indicates how
CC
or
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