LTC3815_15 Datasheet, PDF (19/42 Pages) Linear Technology – 6A Monolithic Synchronous DC/DC Step-Down Converter with Digital Power System Management

LTC3815
Operation
A value shown below a field in the following figures is a
mandatory value for that field.
The data formats implemented by PMBus are:
n _{Master transmitter transmits to slave receiver. The}
transfer direction in this case is not changed.
n _{Master reads slave immediately after the first byte. At}
the moment of the first acknowledgment (provided by
the slave receiver) the master transmitter becomes a
master receiver and the slave receiver becomes a slave
transmitter.
n _{Combined format. During a change of direction within}
a transfer, the master repeats both a start condition
and the slave address but with the R/W bit reversed.
In this case, the master receiver terminates the transfer
by generating a NACK on the last byte of the transfer
and a STOP condition.
Examples of these formats are shown in Figures 3 through 7.
1
7
11
8
1
S SLAVE ADDRESS Wr A COMMAND CODE A
8
DATA BYTE
Figure 3. Write Byte Protocol
11
AP
3815 F03
1
7
11
8
1
8
1
8
11
S SLAVE ADDRESS Wr A COMMAND CODE A DATA BYTE LOW A DATA BYTE HIGH A P
3815 F04
Figure 4. Write Word Protocol
1
7
11
8
11
S SLAVE ADDRESS Wr A COMMAND CODE A P
3815 F05
Figure 5. Send Byte Protocol
1
7
11
8
11
7
11
8
1
8
11
S SLAVE ADDRESS Wr A COMMAND CODE A Sr SLAVE ADDRESS Rd A DATA BYTE LOW A DATA BYTE HIGH A P
Figure 6. Read Word Protocol
1
3815 F06
1
7
11
8
11
8
11
S SLAVE ADDRESS Wr A COMMAND CODE A Sr SLAVE ADDRESS Rd A
Figure 7. Read Byte Protocol
8
DATA BYTE
11
AP
1
3815 F07
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3815p
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