Datasheet

DocID16892 Rev 24 13/39
M24128-BW M24128-BR M24128-BF M24128-DF Device operation
38
4.5 Device addressing
To start communication between the bus master and the slave device, the bus master must
initiate a Start condition. Following this, the bus master sends the device select code, shown
in
Table 2 (on Serial Data (SDA), most significant bit first).
When the device select code is received, the device only responds if the Chip Enable
Address is the same as the value on the Chip Enable (E2, E1, E0) inputs.
The 8
th
bit is the Read/Write bit (RW). This bit is set to 1 for Read and 0 for Write operations.
If a match occurs on the device select code, the corresponding device gives an
acknowledgment on Serial Data (SDA) during the 9
th
bit time. If the device does not match
the device select code, it deselects itself from the bus, and goes into Standby mode.
Table 2. Device select code
Device type identifier
(1)
1. The most significant bit, b7, is sent first.
Chip Enable address
(2)
2. E0, E1 and E2 are compared with the value read on input pins E0, E1,and E2.
RW
b7 b6 b5 b4 b3 b2 b1 b0
Device select code
when addressing the
memory array
1010E2E1E0RW
Device select code
when accessing the
Identification page
1011E2E1E0RW