IDT
®
PC MAIN CLOCK 1520A—03/16/10
ICS9LRS4103
PC MAIN CLOCK
10
General SMBus serial interface information for the ICS9LRS4103
How to Write:
• Controller (host) sends a start bit.
• Controller (host) sends the write address D2
(H)
• ICS clock will acknowledge
• Controller (host) sends the beginning byte location = N
• ICS clock will acknowledge
• Controller (host) sends the data byte count = X
• ICS clock will acknowledge
• Controller (host) starts sending Byte N through
Byte N + X -1
• ICS clock will acknowledge each byte one at a time
• Controller (host) sends a Stop bit
How to Read:
• Controller (host) will send start bit.
• Controller (host) sends the write address D2
(H)
• ICS clock will acknowledge
• Controller (host) sends the begining byte
location = N
• ICS clock will acknowledge
• Controller (host) will send a separate start bit.
• Controller (host) sends the read address D3
(H)
• ICS clock will acknowledge
• ICS clock will send the data byte count = X
• ICS clock sends Byte N + X -1
• ICS clock sends Byte 0 through byte X (if X
(H)
was written to byte 8).
• Controller (host) will need to acknowledge each byte
• Controller (host) will send a not acknowledge bit
• Controller (host) will send a stop bit
Index Block Write Operation
Slave Address D2
(H)
Beginning Byte = N
WRite
Byte N + X - 1
Data Byte Count = X
Beginning Byte N
T starT bit
WR WRite
RT Repeat starT
RD ReaD
Beginning Byte N
Byte N + X - 1
N Not acknowledge
P stoP bit
Slave Address D3
(H)
Index Block Read Operation
Slave Address D2
(H)
Beginning Byte = N
ACK
ACK
Data Byte Count = X
ACK
