Mitsubishi Apricot FT2200, System Manual

Page: 92 / 125

4-12 System Guide
4.3.1 Shadow RAM
The system reserves 384 KB of random access memory (RAM) for the
shadow RAM function. This parameter has eight range addresses.
When you set these addresses to
Enabled , the system BIOS, video
BIOS, and I/O ROM functions run directly from the shadow RAM for
faster operation. When you set them to
Disabled , the functions run
normally from ROM.
The address range E0000h - FFFFFh is for shadowing the system
BIOS. This item is always set to
Enabled
and is not user-
configurable. The address range C0000h - C7FFFh is for shadowing
the video BIOS. This item is fixed to
Enabled .
The remaining address ranges are for I/O ROM functions.
4.3.2 L1 and L2 Cache (CPU Cache)
This parameter enables or disables the first-level and second-level
cache integrated in the Pentium Pro CPU. This item is fixed to
Enabled and is not user-configurable if you enabled the Auto
configuration Mode and Fast Boot Mode parameters on page 2 of the
Basic System Configuration menu.
Cache Scheme
This parameter sets the cache to
Write-through
or
Write-back
modes. Write-back updates the cache but not the memory when
there is a write instruction. It updates the memory only when there is
cache miss or an inconsistency between the cache and the memory.
Write-through updates both the cache and the memory whenever
there is a write instruction.