IBM PCM-6890B manual Memory Hole at 15M-16M, Passive Release, Delayed Transaction, Spread Spectrum

Memory Hole at 15M-16M

You can reserve this area of system memory for ISA adapter ROM. When this area is reserved, it cannot be cached. The user informa- tion of peripherals that need to use this area of system memory usually discusses their memory requirements.

Passive Release

When Enabled, CPU to PCI bus accesses are allowed during passive release. Otherwise, the arbiter only accepts another PCI master access to local DRAM.

Delayed Transaction

The chipset has an embedded 32-bit posted write buffer to support delay transactions cycles. Select Enabled to support compliance with PCI specification version 2.1.

Auto Detect DIMM/PCI Clk

When the Auto Detect DIMM/PCI clk enable, the Utility will automatically detect the DIMM/PCI clock in your system.

Spread Spectrum

When the system clock generator pulses, the extreme values of the pulse generate excess EMI. Enabling pulse spectrum spread modulation changes the extreme values from spikes to flat curves, thus reducing EMI. This benefit may in some cases be outweighed by problems with timing-critical devices, such as a clock-sensitive SCSI device

IN0-IN6(V)

These fields display the current voltage of up to seven voltage input lines, if your computer contains a monitoring system.

60 PCM-6890B User Manual