954226 Datasheet, PDF (8/22 Pages) Integrated Device Technology – Programmable Timing Control HubTM for Mobile P4TM Systems

954226
Programmable Timing Control Hub^TM for Mobile P4^TM Systems
General SMBus serial interface information for the 954226
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 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
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
• Controllor (host) will send a not acknowledge bit
• Controller (host) will send a stop bit
Index Block Write Operation
Controller (Host)
T
starT bit
ICS (Slave/Receiver)
Slave Address D2_(H)
WR
WRite
Beginning Byte = N
Data Byte Count = X
Beginning Byte N
ACK
ACK
ACK
ACK
Byte N + X - 1
P
stoP bit
ACK
* By default, SMBADR = 0,
therefore, SMBus WRITE/READ address is D0/D1.
Please see SMBus Address Selection table on page 1.
Index Block Read Operation
Controller (Host)
T
starT bit
ICS (Slave/Receiver)
Slave Address D2_(H)
WR
WRite
Beginning Byte = N
RT
Repeat starT
ACK
ACK
Slave Address D3_(H)
RD
ReaD
ACK
ACK
ACK
Data Byte Count = X
Beginning Byte N
N
Not acknowledge
P
stoP bit
Byte N + X - 1
IDT^® Programmable Timing Control Hub^TM for Mobile P4^TM Systems
8
0930A—04/13/10