© 2006 Semtech Corp.

POWER MANAGEMENT

SC614

United States Patent No. 6,504,422

www.semtech.com

21

POWER MANAGEMENT

Stop Separated Reads: A further form of read is available which is, in effect, an extension of the combined format

read. This format allows a master to set up the register address pointer for a read, and return to that slave some

time later to read the data. After a start condition, the slave address is sent, followed by a write. The SC614 then

acknowledges that it is being addressed, and the master responds with the 8-bit target register address. The

master then sends a stop or repeated start condition, and may address another slave. Some time later the master

sends a start or repeated start condition, and a valid slave address is sent, followed by a read. The SC614 then

acknowledges and returns the data at the register address location that had previously been set up.

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

P

r

e

t

s

a

M

(

s

e

s

s

e

r

d

d

A

r

e

h

t

O

)

s

e

v

a

l

S

r

S

/

S

s

s

e

r

d

d

A

e

v

a

l

S

RA

a

t

a

D

N

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

Sr:

Repeated Start

R:

Read = 0

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