Advantech AIMB-250 Series 3.5.3.10 Memory Hole At 15M-16M, Delayed Transaction, On-Chip VGA

AIMB-250 Series

3.5.3.10 Memory Hole At 15M-16M

Enabling this feature reserves 15MB to 16MB memory address space to ISA expansion cards that specifically require this setting. This makes the memory from 15MB and up unavailable to the system. Expansion cards can only access memory up to 16MB.

The choice: Enable, Disable.

3.5.3.11 Delayed Transaction

This feature is used to meet the latency of PCI cycles to and from the ISA bus. The ISA bus is much, much slower than the PCI bus. Thus, PCI cycles to and from the ISA bus take a longer time to complete and this slows the PCI bus down.

However, enabling Delayed Transaction enables the chipset's embedded 32-bit posted write buffer to support delayed transaction cycles. This means that transactions to and from the ISA bus are buffered and the PCI bus can be freed to perform other transactions while the ISA transaction is underway.

This option should be enabled for better performance and to meet PCI 2.1 specifications. Disable it only if your PCI cards cannot work properly or if you are using an ISA card that is not PCI 2.1 compliant.

The Choice: Enabled, Disabled.

3.5.3.12 Delay Prior to Thermal

When you system temperature higher, you can set the DRAM access time slowdown between on 4 min – 32 min delay.

The choice: 4 Min, 8 Min, 16 Min, and 32 Min.

3.5.3.13 AGP Aperture Size (MB)

Select the size of Accelerated Graphics Port (AGP) aperture. 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 Choice: 4, 8, 16, 32, 64, 128, 256.

3.5.3.14 Init Display First

This item allows you to decide to active whether PCI Slot or Onboard/AGP first. The choice: PCI Slot, Onboard/AGP.

3.5.3.15 On-Chip VGA

This item is enabled as the onboard VGA is used.

The Choices: Enabled, Disabled.

3.5.3.16 On-Chip Frame Buffer Size

This item is to select the amount of system memory that will be utilized as internal graphics device memory

The choices: 1MB, 4MB, 8MB, 16MB, 32MB.

72 AIMB-250 Series User’s Manual