14.8.14. Miscellaneous Signals - Intel 855PM Design Manual

Platform Design Checklist

14.8.14. Miscellaneous Signals

Pin Name
Pull up/Pull down
SPKR
322
ICH4-M Miscellaneous Signals
System
See notes
Series
Damping
SPKR is a strapping option for the TCO Timer
Reboot function and is sampled on the rising
edge of PWROK. An integrated weak pull down
is enabled only at boot/reset. Status of strap is
readable via the NO_REBOOT bit (D31:F0,
Offset D4h, bit 1)
1 = disabled
0 = enabled (normal operation)
To disable, a jumper can be populated to pull
SPKR high. Value of pull up must be such that
the voltage divider output caused by the pull up,
effective impedance of speaker and codec
circuit, and internal pull down will be read as
logic high (0.5 * Vcc3_3 to Vcc3_3 + 0.5)
®
Intel 855PM Chipset Platform Design Guide
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Notes