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 2005 Semtech Corp.

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POWER MANAGEMENT

SC900

Applications Information (Cont.)

Supported Formats

Direct Format - Write

master responds with an 8-bit data byte consisting of the register address. The slave acknowledges and the

master sends the appropriate 8-bit data byte. Once again the slave acknowledges and the master terminates the

transfer with the stop condition [P].

Combined Format - Read

then acknowledges that it is being addressed, and the master responds with an 8-bit data byte consisting of the

register address. The slave acknowledges and the master sends the repeated start condition [Sr]. Once again the

slave address is sent, followed by an eighth bit indicating a read. The slave responds with an acknowledge and the

previously addressed 8-bit data byte. The master then sends a non-acknowledge (NACK). Finally, the master

terminates the transfer with the stop condition [P].

Register Address

S

S : Start Condition

W: Write = '0'

A : Acknowledge (sent by slave)

Sr: Repeated Start Condition

P : Stop Condition

Slave Address : 7 bit

Register Address : 8 bit

Data : 8 Bit

W

A

A

A

P

Slave Address

Data

S : Start Condition

W: Write = '0'

R : Read = '1'

A : Acknowledge (Sent by Slave)

B : Acknowledge (Sent by Master)

Sr: Repeated Start Condition

P : Stop Condition

Slave Address : 7 bit

Register Address : 8 bit

Data : 8 Bit

Slave Address

Register Address

S

W

A

A

Sr

Data

Slave Address R

A

B

P