American Megatrends MAN-772 manual PCI/PnP Setup, Cont’d, Snoop Bit Action

PCI/PnP Setup

Choose the PCI/PnP Setup icon from the WINBIOS Setup screen to display the PCI and Plug and Play Setup options, described below.

Plug and Play-Aware OS Set this option to Yes if the operating system in this computer is aware of and follows the Plug and Play specification. Windows 95 is PnP- aware. The settings are Yes or No. The Optimal and Fail-Safe default settings are No.

PCI VGA Palette Snoop When this option is set to Enabled, multiple VGA devices operating on different buses can handle data from the CPU on each set of palette registers on every video device. Bit 5 of the command register in the PCI device configuration space is the VGA Palette Snoop bit (0 is disabled). For example: if there are two VGA devices in the computer (one PCI and one ISA) and the VGA Palette Snoop bit is:

Snoop Bit	Action
Disabled	Data read and written by the CPU is only directed to the PCI VGA device's
	palette registers.
Enabled	Data read and written by the CPU is directed to the both the PCI VGA device
	palette registers and the ISA VGA device palette registers, and the palette
	registers of both devices can be identical.
	This option must be set to Enabled if an ISA adapter card installed in the
	system uses VGA palette snooping. The Optimal and Fail-Safe default
	settings are Disabled.

Allocate IRQ to PCI VGA Set this option to Yes to allocate an IRQ to a VGA adapter card that uses the PCI local bus. The settings are Yes or No. The Optimal and Fail- Safe default settings are Yes.

PCI Slot-1 Latency Timer

PCI Slot-2 Latency Timer

PCI Slot-3 Latency Timer

PCI Slot-4 Latency Timer These options specify the latency timings (in PCI clocks) for PCI devices installed in the four PCI expansion slots. The settings are 32, 64, 96, 128, 160, 192, 224, or 248. The Optimal and Fail-Safe default settings are 64.

USB Device Latency Timer This option specifies the latency timings (in PCI clocks) for USB devices installed in the computer. The settings are 32, 64, 96, 128, 160, 192, 224, or 248. The Optimal and Fail-Safe default settings are 64.

USB Device IRQ Preference These options specify the IRQ priority for USB devices installed in the computer. The settings are Auto, IRQ5, IRQ9, IRQ10, IRQ11, IRQ14, and IRQ15, in priority order. If Auto is selected, AMIBIOS automatically determines the optimal IRQ priority order. The Optimal and Fail-Safe default settings are Auto.

PCI Slot-1 IRQ Preference

PCI Slot-2 IRQ Preference

PCI Slot-3 IRQ Preference

PCI Slot-4 IRQ Preference These options specify the IRQ priority for PCI devices installed in the four PCI expansion slots. The settings are Auto, IRQ5, IRQ9, IRQ10, IRQ11, IRQ 14, and IRQ15, in priority order. If Auto is selected, AMIBIOS automatically determines the optimal IRQ priority order. The Optimal and Fail-Safe default settings are Auto.

Cont’d

Chapter 2 WINBIOS Setup 55