Rainbow Electronics MAX16068 - Manual (Page 29)

______________________________________________________________________________________ 29
MAX16068
6-Channel, Flash-Configurable System Manager
with Nonvolatile Fault Registers
Figure 9. SMBus Protocols
SEND BYTE FORMAT
S ADDRESS
SLAVE ADDRESS: Address
of the slave on the serial
interface bus. DATA BYTE: Presets the internal
address pointer or represents
a command.
R/W ACK COMMAND ACK P
7 BITS 0 0 0 8 BITS
RECEIVE BYTE FORMAT
S ADDRESS
SLAVE ADDRESS: Address
of the slave on the serial
interface bus. DATA BYTE: Data is read from
the location pointed to by the
internal address pointer.
R/W ACK DATA NACK P
7 BITS 1 0
0 1
1 8 BITS
WRITE BYTE FORMAT
S ADDRESS
SLAVE ADDRESS: Address
of the slave on the serial
interface bus. COMMAND BYTE:
Sets the internal
address pointer.
R/W ACK COMMAND ACK
7 BITS 0 0 0 0 8 BITS
DATA BYTE: Data is written to
the locations set by the
internal address pointer.
DATA ACK P
8 BITS
READ BYTE FORMAT
S
SLAVE
ADDRESS
SLAVE ADDRESS: Address
of the slave on the serial
interface bus. COMMAND BYTE:
Sets the internal
address pointer.
R/W
R/W
ACK COMMAND ACK
7 BITS 0 0 0 0 1 8 BITS
DATA BYTE: Data is written to
the locations set by the
internal address pointer.
SR
R/W R/W
SLAVE
ADDRESS
R/W
7 BITS 1
BLOCK WRITE FORMAT
S ADDRESS
SLAVE ADDRESS: Address
of the slave on the
serial interface bus. COMMAND BYTE:
FAh DATA BYTE: Data is written to the locations
set by the internal address pointer.
ACK COMMAND ACK
7 BITS 0 0 0 0 0 0 0 8 BITS
BYTE
COUNT = N
ACK P
8 BITS
DATA BYTE 1 ACK
8 BITS
DATA BYTE N ACK
8 BITS
DATA BYTE … ACK
ACK DATA BYTE
8 BITS
8 BITS
SMBALERT#
ALERT RESPONSE ADDRESS:
Only the device that
interrupted the master
responds to this address. SLAVE ADDRESS: Slave places
its own address on the
serial bus.
S ADDRESS R/W ACK DATA NACK P
0001100 D.C. 8 BITS
NACK P
SLAVE TO MASTER
MASTER TO SLAVE
BLOCK READ FORMAT
S ADDRESS
SLAVE ADDRESS: Address
of the slave on the
serial interface bus.
S = START CONDITION
P = STOP CONDITION
Sr = REPEATED START CONDITION
D.C. = DON’T CARE ACK = ACKNOWLEDGE, SDA PULLED LOW DURING RISING EDGE OF SCL.
NACK = NOT ACKNOWLEDGE, SDA LEFT HIGH DURING RISING EDGE OF SCL.
ALL DATA IS CLOCKED IN/OUT OF THE DEVICE ON RISING EDGES OF SCL.
= SDA TRANSITIONS FROM HIGH TO LOW DURING PERIOD OF SCL.
= SDA TRANSITIONS FROM LOW TO HIGH DURING PERIOD OF SCL.
COMMAND BYTE:
FBh DATA BYTE: Data is read from the locations
set by the internal address pointer.
ACK COMMAND ACK
7 BITS
ADDRESS
SLAVE ADDRESS: Address
of the slave on the
serial interface bus.
7 BITS 0 0 0 0 0 0 0 1 8 BITS
ACK P
8 BITS
DATA BYTE N ACK
8 BITS
ACK DATA BYTE N
8 BITS
DATA BYTE … NACK
8 BITS
SR ACK
1
BYTE
COUNT = N
S ADDRESS COMMAND PEC P
7 BITS 0 0 8 BITS 0
WRITE BYTE FORMAT WITH PEC
READ BYTE FORMAT WITH PEC
BLOCK WRITE WITH PEC
BLOCK READ WITH PEC
DATA
0 8 BITS 0 8 BITS
S
S
S
ADDRESS COMMAND DATA PEC P
P
SR
SR
ADDRESS
0 0
0
1
0
0 0
0 0 0
0 0
NACK
1
P
0
0 0
8 BITS 0
0
0
8 BITS
COMMAND
8 BITS
COMMAND
8 BITS
0
0
0
8 BITS
DATA N
8 BITS
DATA N
8 BITS
PEC
8 BITS
PEC
8 BITS
0 7 BITS
ADDRESS
7 BITS
ADDRESS
7 BITS
1 1 7 BITS
BYTE COUNT N
8 BITS
BYTE COUNT N
8 BITS
ADDRESS
7 BITS
DATA BYTE 1
8 BITS
DATA BYTE 1
8 BITS
DATA BYTE
8 BITS
DATA BYTE
8 BITS
R/W
R/W R/W
R/W
R/W R/W
ACK ACK ACK ACK
ACK ACK ACK ACK NACK
ACK ACK ACK ACK ACK ACK
ACK ACK ACK ACK ACK ACK ACK
ACK