AMD SC2200 Computer Hardware User Manual


 
210 AMD Geode™ SC2200 Processor Data Book
Core Logic Module - Bridge, GPIO, and LPC Registers - Function 0
32580B
Index 80h Power Management Enable Register 1 (R/W) Reset Value: 00h
7:6 Reserved. Must be set to 0.
5 Codec SDATA_IN SMI. When set to 1, this bit allows an SMI to be generated in response to an AC97 codec producing a
positive edge on SDATA_IN.
0: Disable.
1: Enable.
Top level SMI status is reported at F1BAR0+I/O Offset 00h/02h[0].
Second level SMI status is reported at F0 Index 87h/F7h[2].
4 Video Speedup. Any video activity, as decoded from the serial connection (PSERIAL) from the GX1 module disables clock
throttling (via internal SUSP#/SUSPA# handshake) for a configurable duration when system is power-managed using CPU
Suspend modulation.
0: Disable.
1: Enable.
The duration of the speedup is configured in the Video Speedup Timer Count Register (F0 Index 8Dh). Detection of an
external VGA access (3Bx, 3Cx, 3Dx and A000h-B7FFh) on the PCI bus is also supported. This configuration is non-stan-
dard, but it does allow the power management routines to support an external VGA chip.
3 IRQ Speedup. Any unmasked IRQ (per I/O Ports 021h/0A1h) or SMI disables clock throttling (via internal SUSP#/SUSPA#
handshake) for a configurable duration when system is power-managed using CPU Suspend modulation.
0: Disable.
1: Enable.
The duration of the speedup is configured in the IRQ Speedup Timer Count Register (F0 Index 8Ch).
2 Traps. Globally enable all power management I/O traps.
0: Disable.
1: Enable.
This excludes the audio I/O traps, which are enabled via F3BAR0+Memory Offset 18h.
1 Timers. General Purpose and Device Idle Timers.
0: Disable.
1: Enable.
Note: Disable at this level does not reload the timers on the enable. The timers are disabled at their current counts.
This bit has no affect on the Suspend Modulation register (F0 Index 94h).
Only applicable when in APM mode (F1BAR1+I/O Offset 0Ch[0] = 0) and not ACPI mode.
0 Power Management. Global power management.
0: Disable.
1: Enable.
This bit must be set to 1 immediately after POST for power management resources to function.
Index 81h Power Management Enable Register 2 (R/W) Reset Value: 00h
7 Video Access Idle Timer Enable. Turn on Video Idle Timer Count Register (F0 Index A6h) and generate an SMI when the
timer expires.
0: Disable.
1: Enable.
If an access occurs in the video address range (sets bit 0 of the GX1 module’s PSERIAL register) the timer is reloaded with
the programmed count.
Top level SMI status is reported at F1BAR0+I/O Offset 00h/02h[0].
Second level SMI status is reported at F0 Index 85h/F5h[7].
Table 6-29. F0: PCI Header/Bridge Configuration Registers for GPIO and LPC Support (Continued)
Bit Description