Platform Design Checklist
R
322
Intel
®
855PM Chipset Platform Design Guide
14.8.14.
Miscellaneous Signals
ICH4-M Miscellaneous Signals
Pin Name
System
Pull up/Pull down
Series
Damping
Notes
9
SPKR
See notes
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 0.5)