Datasheet

MAX34446
PMBus Power-Supply Data Logger
10Maxim Integrated
Table 2. PMBus/SMBus Serial-Port Address
Address Select
On device power-up or reset, the device samples the A0
and A1 pins to determine the PMBus/SMBus serial-port
address. See Table 2.
SMBus/PMBus Operation
The device implements the PMBus command structure
using the SMBus format. The structure of the data flow
between the host and the slave is shown below for sev-
eral different types of transactions. Data is sent most
significant bit (MSB) first.
SMBus/PMBus Communication Examples
A1 A0
7-BIT SLAVE
ADDRESS
100kI to V
SS
100kI to V
SS
0010 010 (24h)
100kI to V
DD
0010 011 (26h)
100kI to V
DD
100kI to V
SS
0010 100 (28h)
100kI to V
DD
0010 101 (2Ah)
READ WORD FORMAT
1 7 1 1 8 1 1 7 1 1 8 1 8 1 1
S
SLAVE
ADDRESS
W A
COMMAND
CODE
A Sr
SLAVE
ADDRESS
R A
DATA BYTE
LOW
A
DATA BYTE
HIGH
NA P
READ BYTE FORMAT
1 7 1 1 8 1 1 7 1 1 8 1 1
S
SLAVE
ADDRESS
W A
COMMAND
CODE
A Sr
SLAVE
ADDRESS
R A DATA BYTE NA P
WRITE WORD FORMAT
1 7 1 1 8 1 8 1 8 1 1
S
SLAVE
ADDRESS
W A
COMMAND
CODE
A
DATA BYTE
LOW
A
DATA BYTE
HIGH
A P
WRITE BYTE FORMAT
1 7 1 1 8 1 8 1 1
S
SLAVE
ADDRESS
W A
COMMAND
CODE
A DATA BYTE A P
SEND BYTE FORMAT
1 7 1 1 8 1 1
S
SLAVE
ADDRESS
W A
COMMAND
CODE
A P
KEY:
S = START
Sr = REPEATED START
P = STOP
W = WRITE BIT (0)
R = READ BIT (1)
A = ACKNOWLEDGE (0)
NA = NOT ACKNOWLEDGE (1)
SHADED BLOCK = SLAVE TRANSACTION