CAT5269_13 Datasheet, PDF (8/15 Pages) ON Semiconductor – Dual Digital Potentiometer (POT)

CAT5269
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.
SCL
SDA
8TH BIT
BYTE n
ACK
t_WR
STOP
CONDITION
Figure 3. Write Cycle Timing
START
CONDITION
ADDRESS
SDA
SCL
START CONDITION
STOP CONDITION
Figure 4. Start/Stop Condition
SCL FROM
MASTER
1
8
9
DATA OUTPUT
FROM TRANSMITTER
DATA OUTPUT
FROM RECEIVER
START
Figure 5. Acknowledge Condition
ACKNOWLEDGE
CAT5269 0 1 0 1 A3 A2 A1 A0
Figure 6. Slave Address Bits
* 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.
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