
ISL97635
SMBCLK
t LOW
t R
t F
V IH
V IL
t HD:STA
t HD:DAT
t HIGH
t SU:DAT
t SU:STA
t SU:STO
SMBDAT
V IH
V IL
P
t BUF
S
S
P
NOTES:
SMBus Description
S = Start condition
P = Stop condition
A = Acknowledge
A = Not acknowledge
R/W = Read enable at high; write enable at low
FIGURE 19. SMBUS INTERFACE
1
S
7
SLAVE ADDRESS
1
W
1
A
8
COMMAND CODE
1
A
8
DATA BYTE
1
A
1
P
Master to Slave
Slave to Master
FIGURE 20. WRITE BYTE PROTOCOL
1
S
7
SLAVE ADDRESS
1
W
1
A
8
COMMAND CODE
1
A
1
S
8
SLAVE ADDRESS
1
R
1
A
8
DATA BYTE
1
A
1
P
Master to Slave
Slave to Master
FIGURE 21. READ BYTE PROTOCOL
17
FN6434.2
December 22, 2008