Shadow Ram; Internal Cache; System Cache - Mitsubishi Electric APRICOT FT//EX User Manual

5.2.1

Shadow RAM

The system reserves 384 KB of random access memory (RAM) for shadow
RAM. This parameter has seven range addresses. When you set these addresses
to Enable, the video BIOS, I/O ROM, and system BIOS functions run directly
from the shadow RAM. When you set them to Disable, the functions run
normally from ROM.
The address F0000h-FFFFFh is for system BIOS and C0000h-C7FFFh is for
shadowing video BIOS. The next five address ranges, C8000h to EFFFFh, are
for I/O ROM functions.
The System BIOS default setting is Enable while its bootable setting is Disable.
5.2.2

Internal Cache

The Internal Cache is the buffer in the CPU itself. The default setting is
Enabled.
5.2.3

System Cache

Set the cache controller on and off with this parameter. The default setting is
On. The bootable setting is Off.
Cache Scheme
The Cache Scheme parameter sets the cache to Write Back or Write Buffer
modes. Write Back updates the cache but not the memory when there is a write
instruction. It updates the memory only when the cache is already full. Write
Buffer updates both the memory and the cache whenever there is a write
instruction.
For better system performance, both the system default and bootable setting is
Write Back.
Configuring the System 5-1