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POWER MANAGEMENT

SC905A

Stop-Separated Reads

Stop-separated reads can also be used. This format allows a master to set up the register address pointer for a read

and return to that slave at a later time to read the data. In this format the slave address followed by a write command

are sent after a start [S] condition. The SC905A then acknowledges it is being addressed, and the master responds

with the 8-bit register address. The master sends a stop or restart condition and may then address another slave. After

performing other tasks, the master can send a start or restart condition to the SC905A with a read command. The

Slave Address

Register Address

Slave Address B

Data

NACK

S

W A

A

S/Sr

R A

P

P

Slave Address A

S

S: Start Condition

Slave Address: 7-bit

W: Write = ‘0’

Register Address: 8-bit

R: Read = ‘1’

Data: 8-bit

A: Acknowledge (sent by slave)

NACK: Non-Acknowledge (sent by master)

Sr: Repeated Start Condition

P: Stop condition

I

Register Address Setup Access

Master Addresses

other Slaves

Register Read Access