ETX-CV
User’s Manual
Page 36
7.5
PCI Interrupt Routing Map
PIRQ
A
B
C
D
E
F
G
H
INT Line
INTA
INTB
INTC
INTD
VGA
X
UHCI 1
X
UHCI 2
X
UHCI 3
X
UHCI 4
X
EHCI
X
SATA
X
SMBus
X
Audio
X
PCI Slot1
INTA
INTB
INTC
INTD
PCI Slot2
INTB
INTC
INTD
INTA
PCI Slot3
INTC
INTD
INTA
INTB
PCI Slot4
INTD
INTA
INTB
INTC
LAN
INTA
7.6
System Management Bus (I2C-compatible)
Internally the SMB bus and I2C bus are one and the same. The ICH7-M Southbridge supports
SMBDAT and SMBCLK lines that are I2C-compatible.
The X4 connector has pins for both the I2C and SMB bus. Both are connected to the same
internal bus: the SMB bus. It is advisable to always connect external I2C devices to the I2C pins
and SMB devices to the SMB pins to ensure compatibility with other modules that might support
two internal busses (a separate I2C and SMB bus).
Address
Function
Device
2Eh
Super I/O Read/Write
SIO
A0h
Memory SPD
SO-DIMM
D2h
Clock Generator
CLK GEN