Datasheet

MAX34451 PMBus 16-Channel V/I Monitor and
12-Channel Sequencer/Marginer
www.maximintegrated.com
Maxim Integrated │ 18
Group Command
Thedevicesupportsthegroupcommand.Withthegroup
command, a host can write different data to multiple
devices on the same serial bus with one long continuous
data stream. All the devices addressed during this trans-
actionwaitforthehosttoissueaSTOPbeforebeginning
to respond to the command.
Group Command Write Format
Addressing
The device responds to receiving its fixed slave address
by asserting an acknowledge (ACK) on the bus. The
device does not respond to a general call address; it
only responds when it receives its fixed slave address
orthealertresponseaddress.SeetheALERT and Alert
Response Address (ARA) section for more details.
ALERT and Alert Response Address (ARA)
If the ALERT output is enabled (ALERT bit = 1 in
MFR_MODE) when a fault occurs, the device asserts
the ALERT signal and then waits for the host to send an
ARA, as shown in the Alert Response Address (ARA)
Byte Format section.
Alert Response Address (ARA) Byte Format
When the ARA is received and the device is asserting
ALERT,thedeviceACKsitandthenattemptstoplaceits
fixed slave address on the bus by arbitrating the bus, since
anotherdevicecouldalsotrytorespondtotheARA.The
rules of arbitration state that the lowest address device
wins. If the device wins the arbitration, it deasserts ALERT.
If the device loses arbitration, it keeps ALERT asserted and
waitsforthehosttoonceagainsendtheARA.
SLAVE ADDRESS, COMMAND BYTE, AND DATA WORD FOR DEVICE 1
1 7 1 1 8 1 8 1 8 1
S
SLAVE
ADDRESS
W A
COMMAND
CODE
A
DATABYTE
LOW
A
DATABYTE
HIGH
A
U U U
SLAVE ADDRESS, COMMAND BYTE, AND DATA BYTE FOR DEVICE 2
1 7 1 1 8 1 8 1
Sr
SLAVE
ADDRESS
W A
COMMAND
CODE
A
DATABYTE A
U U U
SLAVE ADDRESS AND SEND BYTE FOR DEVICE 3
1 7 1 1 8 1
Sr
SLAVE
ADDRESS
W A
COMMAND
CODE
A
U U U
U U U
SLAVE ADDRESS, COMMAND BYTE, AND DATA WORD FOR DEVICE N
1 7 1 1 8 1 8 1 8 1 1
Sr
SLAVE
ADDRESS
W A
COMMAND
CODE
A
DATABYTE
LOW
A
DATABYTE
HIGH
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
1 7 1 1 8 1 1
S
ARA
0001100
R A
DEVICESLAVE
ADDRESSWITHLSB=0
NA P