The s/pdif module is purchased separately, Digital audio connector, Spdif_out – Asus P2-P5945GC User Manual
Page 54: Back_audio connector back_audio
4-9
ASUS P1/P2-P5945GC
7. Back audio connector (20-1 pin Back_Audio Connector)
We recommend that you connect a high-definition front panel audio
module to this connector to avail of the motherboard’s high-definition
audio capability.
8. Digital audio connector (4-1 pin SPDIF_OUT)
This connector is for an additional Sony/Philips Digital Interface
(S/PDIF) port(s). Connect the S/PDIF module cable to this connector,
then install the module to a slot opening at the back of the system
chassis.
The S/PDIF module is purchased separately.
R
Digital Audio Connector
+5V
SPDIFOU
T
GND
SPDIF_OUT
R
Back_Audio Connector
BACK_AUDIO
BCAZ LIN1
L
BCAZ LIN1
R
SENSE LIN1
BCAZ FRONT
L
BCAZ FRONTR
SENSE FRONT
BCAZ MIC1L
BCAZ MIC1R
SENSE MIC1
BCAZ CEN
L
BCAZ LEF
R
SENSE CN1
BCAZ SURBL
BCAZ SURBR
SENSE SURB
BCAZ SUR
L
BCAZ SUR
R
SENSE SUR
AGND_A
SPDIF_OUT module