EVAL-ADM1275EBZ Datasheet, PDF (28/48 Pages) Analog Devices – Hot-Swap Controller and Digital Power

ADM1275
Data Sheet
SMBus MESSAGE FORMATS
Figure 58 to Figure 65 show all the SMBus protocols supported
by the ADM1275, along with the PEC variant. In these figures,
unshaded cells indicate that the bus host is actively driving the
bus; shaded cells indicate that the ADM1275 is driving the bus.
Figure 58 to Figure 65 use the following abbreviations:
S = start condition
Sr = repeated start condition
P = stop condition
R = read bit
W = write bit
A = acknowledge bit (0)
A = acknowledge bit (1)
“A” represents the ACK (acknowledge) bit. The ACK bit is typi-
cally active low (Logic 0) if the transmitted byte is successfully
received by a device. However, when the receiving device is the
bus master, the acknowledge bit for the last byte read is a Logic 1,
indicated by A.
S
SLAVE ADDRESS
WA
DATA BYTE
AP
S
SLAVE ADDRESS
WA
DATA BYTE
A
PEC
MASTER TO SLAVE
SLAVE TO MASTER
Figure 58. Send Byte and Send Byte with PEC
AP
S
SLAVE ADDRESS
RA
DATA BYTE
AP
S
SLAVE ADDRESS
RA
DATA BYTE
A
PEC
MASTER TO SLAVE
SLAVE TO MASTER
Figure 59. Receive Byte and Receive Byte with PEC
AP
S
SLAVE ADDRESS
WA
COMMAND CODE
A
DATA BYTE
AP
S
SLAVE ADDRESS
WA
COMMAND CODE
A
DATA BYTE
A
PEC
MASTER TO SLAVE
SLAVE TO MASTER
Figure 60. Write Byte and Write Byte with PEC
AP
S
SLAVE ADDRESS
WA
COMMAND CODE
A Sr SLAVE ADDRESS
RA
DATA BYTE
AP
S
SLAVE ADDRESS
WA
COMMAND CODE
A Sr SLAVE ADDRESS
RA
DATA BYTE
A
PEC
MASTER TO SLAVE
SLAVE TO MASTER
Figure 61. Read Byte and Read Byte with PEC
AP
S
SLAVE ADDRESS
W A COMMAND CODE
A
DATA BYTE LOW
A
DATA BYTE HIGH
AP
S
SLAVE ADDRESS
W A COMMAND CODE
A
DATA BYTE LOW
A
DATA BYTE HIGH A
PEC
MASTER TO SLAVE
SLAVE TO MASTER
Figure 62. Write Word and Write Word with PEC
AP
S
SLAVE ADDRESS
WA
COMMAND CODE
DATA BYTE HIGH
AP
A Sr SLAVE ADDRESS
RA
DATA BYTE LOW
A
S
SLAVE ADDRESS
WA
COMMAND CODE
A Sr SLAVE ADDRESS
RA
DATA BYTE LOW
A
DATA BYTE HIGH
A
MASTER TO SLAVE
SLAVE TO MASTER
PEC
AP
Figure 63. Read Word and Read Word with PEC
Rev. D | Page 28 of 48