M24M02-DR datasheet(14/38 Pages) STMICROELECTRONICS

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Instructions

M24M02-DR

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DocID18204 Rev 8

Instructions

5.1

Write operations

Following a Start condition the bus master sends a device select code with the R/W bit (RW)

reset to 0. The device acknowledges this, as shown in Figure 7, and waits for two address

bytes. The device responds to each address byte with an acknowledge bit, and then waits

for the data byte.

The 256 Kbytes (2 Mb) are addressed with 18 address bits, the 16 lower address bits being

defined by the two address bytes and the most significant address bits (A17, A16) being

included in the Device Select code (see Table 4).

When the bus master generates a Stop condition immediately after a data byte Ack bit (in

the “10th bit” time slot), either at the end of a Byte Write or a Page Write, the internal Write

cycle tW is triggered. A Stop condition at any other time slot does not trigger the internal

Write cycle.

After the Stop condition and the successful completion of an internal Write cycle (tW), the

device internal address counter is automatically incremented to point to the next byte after

the last modified byte.

During the internal Write cycle, Serial Data (SDA) is disabled internally, and the device does

not respond to any requests.

If the Write Control input (WC) is driven High, the Write instruction is not executed and the

accompanying data bytes are not acknowledged, as shown in Figure 8.

Table 4. Most significant address byte

A15

A14

A13

A12

A11

A10

Table 5. Least significant address byte

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