© 2006 Semtech Corp.

POWER MANAGEMENT

SC614

United States Patent No. 6,504,422

www.semtech.com

20

program flexibility, in that once the slave address has been sent to the SC614 enabling it to be a slave

transmitter/receiver any register can be written or, read from independently of each other. While there is no auto

the next register independent 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

SC614. The SC614 is not CBUS compatible. Finally, the SC614 can operate in standard mode (100kbit/s) or fast

mode (400kbit/s).

Supported Formats

condition, the slave address is sent followed by an eighth bit indicating a write. The SC614 then acknowledges that

it is being addressed, and the master responds with an 8-bit data byte consisting of the target 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 a stop condition.

S

s

s

e

r

d

d

A

e

v

a

l

S

WA

s

s

e

r

d

d

A

r

e

t

s

i

g

e

RA

a

t

a

DA

P

S:

Start Condition

Slave Address:

7 bit

W:

Write = 0

Register Address:

8 bit

A:

Acknowledge (SDA low)

Data:

8 bit

P:

Stop Condition

Shaded represents transmission from master to slave and unshaded represents transmission from slave to master.

Combined Format (Read/Write): After a start condition, the slave address is sent followed by an eighth bit

indicating a write. The SC614 then acknowledges that it is being addressed, and the master responds with an 8 bit

data byte consisting of the target register address. The slave acknowledges once more and the master sends the

repeated start condition. Once again, the slave address is sent, followed by an eighth bit indicating a read or write.

The slave responds with an acknowledge. If the command was a write, the master sends the appropriate 8-bit data

byte. Once again the slave acknowledges and the master terminates the transfer with a stop condition. If the

command was a read, the slave sends the appropriate 8-bit data byte, to which the master sends a not

acknowledge and then terminates the transfer with a stop condition.

S

s

s

e

r

d

d

A

e

v

a

l

S

WA

s

s

e

r

d

d

A

r

e

t

s

i

g

e

RA

r

S

s

s

e

r

d

d

A

e

v

a

l

S

W

/

RA

a

t

a

D

)

1

(

N

/

A

)

1

(

P

S:

Start Condition

N:

W:

Write = 0

P:

Stop Condition

A:

Acknowledge (SDA low)

Slave Address:

7 bit

Sr:

Repeated Start Condition

Register Address:

8 bit

R:

Read = 1

Data:

8 bit

Shaded represents transmission from master to slave and unshaded represents transmission from slave to master.

(1) Not shaded because transfer direction depends upon R/W bit.