CAT5269

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8

WRITE PROTECTION

The Write Protection feature allows the user to protect

against inadvertent programming of the non-volatile data

registers. If the WP pin is tied to LOW, the data registers are

protected and become read only. Similarly, the WP pin going

low after start will interrupt a nonvolatile write to data

registers, while the WP pin going low after an internal write

cycle has stated will have no effect on any write operation

(see also CAT5409 or CAT5259). The CAT5269 will accept

both slave addresses and instructions, but the data registers

are protected from programming by the device’s failure to

send an acknowledge after data is received.

STOP

CONDITION

START

CONDITION

ADDRESS

ACK

8TH BIT

BYTE n

SCL

SDA

Figure 3. Write Cycle Timing

Figure 4. Start/Stop Condition

START CONDITION

SDA

STOP CONDITION

SCL

Figure 5. Acknowledge Condition

ACKNOWLEDGE

1

START

SCL FROM

MASTER

89

DATA OUTPUT

FROM TRANSMITTER

DATA OUTPUT

FROM RECEIVER

Figure 6. Slave Address Bits

0

1

0

1

A3

A2

A1

A0

CAT5269

* A0, A1, A2 and A3 correspond to pin A0, A1, A2 and A3 of the device.

** A0, A1, A2 and A3 must compare to its corresponding hard wired input pins.