ETX-CN700
Appendix 1
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FRAME#
Cycle Frame of PCI Buses. This indicates the beginning and duration of a PCI access. The access will be either
an output driven by the Northbridge on behalf of the CPU, or an input during PCI master access.
PCIRST#
PCI Bus Reset. This is an output signal to reset the entire PCI Bus. This signal is asserted during system reset.
INTA#, INTB#, INTC#, INTD#
PCI interrupts. These interrupts are sharable and are typically wired in rotation to PCI slots or devices.
IDSEL
This pin is not present on the ETX module connector, but it is present on each PCI slot connector or device.
IDSEL is an input to the device that is used to set the device’s configuration address for PCI configuration
cycles. The IDSEL pin of each device is typically connected to one of the AD lines in order to set a unique
configuration address. In ETX systems, the four external bus slots or devices are assumed to use AD[19..22] for
IDSEL connections.
USB Signals
USB signal termination components are integrated on the ETX board. In applications using external USB
devices, baseboard designers will typically include USB protection components on the baseboard, including
power supply current limiting or fusing components. USB data signals should be routed as differential pairs.
USB0, USB0#
Universal Serial Bus Port 0. These are the serial differential data pairs for USB Port 0. USB0 – positive signal.
USB0# – negative signal.
USB1, USB1#
Universal Serial Bus Port 1. These are the serial differential data pairs for USB Port 1. USB1 – positive signal.
USB1# – negative signal.
USB2, USB2#
Universal Serial Bus Port 2. These are the serial differential data pairs for USB Port 2. USB2 – positive signal.
USB2# – negative signal.
USB3, USB3#
Universal Serial Bus Port 3. These are the serial differential data pairs for USB Port 3. USB3 – positive signal.
USB3# – negative signal.
Audio Signals
SNDL/ SNDR
Line-level stereo output left/ right. These outputs have a nominal level of 1 volt RMS into a 10K impedance
load. These outputs cannot drive low-impedance speakers directly.
AUXAL/ AUXAR
Auxiliary A input left/ right. Normally intended for connection to an internal or external CDROM analog output
or a similar line-level audio source. Minimum input impedance is 5KOhm.
Nominal input level is 1 volt RMS.
MIC
Microphone input. Minimum input impedance is 5KOhm, max. input voltage is 0.15 Vpk-pk.
ASGND
Analog ground for sound controller. Use this signal ground for an external amplifier in order to achieve lowest
audio noise levels.
ASVCC
Analog supply voltage for sound controller. This is an output which is used for production test only. Do not
make external connections to this pin.
Miscellaneous
SERIRQ
Serial interrupt request. This pin is used to support the serial interrupt protocol.