ICS9DB401 Datasheet, PDF (8/16 Pages) Integrated Circuit Systems – Four Output Differential Buffer for PCI Express

Integrated
Circuit
Systems, Inc.
ICS9DB401
General SMBus serial interface information for the ICS9DB401
How to Write:
• Controller (host) sends a start bit.
• Controller (host) sends the write address DC _(H)
• ICS clock will acknowledge
• Controller (host) sends the begining 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
(see Note 2)
• ICS clock will acknowledge each byte one at a time
• Controller (host) sends a Stop bit
Index Block Write Operation
Controller (Host)
T
starT bit
ICS (Slave/Receiver)
Slave Address DC_(H)
WR
WRite
ACK
Beginning Byte = N
ACK
Data Byte Count = X
ACK
Beginning Byte N
ACK
Byte N + X - 1
P
stoP bit
ACK
How to Read:
• Controller (host) will send start bit.
• Controller (host) sends the write address DC _(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 DD _(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
• Controllor (host) will send a not acknowledge bit
• Controller (host) will send a stop bit
Index Block Read Operation
Controller (Host)
ICS (Slave/Receiver)
T
starT bit
Slave Address DC_(H)
WR
WRite
ACK
Beginning Byte = N
ACK
RT
Repeat starT
Slave Address DD_(H)
RD
ReaD
ACK
ACK
ACK
Data Byte Count = X
Beginning Byte N
1014B—09/07/06
N Not acknowledge
P
stoP bit
Byte N + X - 1
8