ary, 2000. The SC620 has eight user-accessible internal

8-bit registers. While there is no auto increment/decrement

be designed to randomly access the next register indepen-

dent of which register you begin accessing. The start and

stop commands frame the data-packet and the repeat start

condition is allowed if necessary.

Seven bit addressing is used and ten bit addressing is not

allowed. Any general call address will be ignored by the

SC620. The SC620 is not CBUS compatible. The SC620

can operate in standard mode (100kbit/s) or fast mode

(400kbit/s).

Supported Formats:

Direct Format - Write

the start condition [S], the slave address is sent, followed

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 appropriate 8 bit data byte. Once again the slave ac-

knowledges and the master terminates the transfer with

the stop condition [P].

Combined Format - Read

After the start condition [S], the slave address is sent, fol-

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].

Stop Separated Reads

Stop separated reads can also be used. This format al-

lows 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 SC620

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 SC620 with a read com-

mand. The SC620 acknowledges this request and returns

the data from the register location that had previously

been set up.

9

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POWER MANAGEMENT

SC620