IBM CI5VGM Series Video Bios Cacheable, System Bios Cacheable, Memory Hole at 15MB 16MB

Models: CI5VGM Series

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Chapter 3 BIOS Configuration

Video BIOS Cacheable

When enabled, access to video BIOS addressed at C0000H to C7FFFH is cached, provided that the cache controller is disabled.

System BIOS Cacheable

When enabled, access to the system BIOS ROM addressed at F0000H-FFFFFH is cached, provided that the cache controller is disabled.

Memory Hole at 15MB - 16MB

In order to improve performance, certain space in memory can be reserved for ISA cards. This field allows you to reserve 15MB to 16MB memory address space to ISA expansion cards. This makes memory from 15MB and up unavailable to the system. Expansion cards can only access memory up to 16MB. By default, this field is set to Disabled.

AGP Aperture Size (MB)

The field sets aperture size of the graphics. The aperture is a portion of the PCI memory address range dedicated for graphics memory address space. Host cycles that hit the aperture range are forwarded to the AGP without any translation. The options available are 4M, 8M, 16M, 32M, 64M, 128M and 256M. The default setting is 64M.

Cyrix M2 ADS# delay

This field is only visible when your system supports a Cyrix M2 processor. It enables or disables the ADS# delay signal for Cyrix M2.

Auto Detect DIMM/PCI Clk

When enabled, the system automatically shuts off clocks of unused DIMM/PCI slots. The default setting is Disabled. This field is for CE testing use only.

Spread Spectrum

This field sets the value of the spread spectrum. Options are Disabled, 1.8% (CNTR), 0.6% (CNTR), 1.8% (DOWN), and 0.6% (DOWN). The default setting is 0.6% (DOWN). The default setting is Disabled. This field is for CE testing use only.

OnChip USB

This filed allows you to enable or disable the USB function. The default setting is Enabled.

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CI5VGM User’s Manual

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IBM CI5VGM Series Video Bios Cacheable, System Bios Cacheable, Memory Hole at 15MB 16MB, AGP Aperture Size MB, OnChip USB