Ac '97 Interface - Intel 852GM Design Manual

Platform Design Checklist
14.8.5.

AC '97 Interface

Pin Name
AC_BIT_CLK
AC_SDATAIN[2:0]
AC_SDATAOUT
AC_SYNC
260
System Series
Termination
Pull-up/Pull-down
Resistor
None 33-47 Ω
None 33-47 Ω
33-47 Ω
None
33-47 Ω
None
Notes
The internal pull-down resistor is controlled by the
AC'97 Global Control Register, ACLINK Shut Off
bit:
1 = enabled; 0 = disabled
When no AC'97 devices are connected to the
link, BIOS must set the ACLINK Shut Off bit for
the internal keeper resistors to be ENABLED. At
that point, pull-ups/pull-downs are NOT needed
on ANY of the link signals.
A series termination resistor is required for the
PRIMARY CODEC.
A series termination resistor is required for the
SECONDARY and TERTIARY CODEC if the
resistor is not found on CODEC.
A series termination resistor is required for the
PRIMARY CODEC.
One series termination resistor is required for the
SECONDARY/ TERTIARY CODEC connector
card if the resistor is not found on the connector
card.
A series termination resistor is required for the
PRIMARY CODEC.
One series termination resistor is required for the
SECONDARY/ TERTIARY CODEC connector
card if the resistor is not found on the connector
card.
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Intel 852GM Chipset Platform Design Guide
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