MD3331-D64-V3 M-Systems Inc., MD3331-D64-V3 Datasheet - Page 42

• Manufacturer Part Number: MD3331-D64-V3
• Description: Diskonchip Millennium Plus
• Manufacturer: M-Systems Inc.

8.
8.1
DiskOnChip Millennium Plus can function both as a flash disk and the system boot device.
If DiskOnChip is configured as a flash disk, it can operate as the OS boot device. DiskOnChip default firmware
contains drivers to enable it to perform as the OS boot device under DOS (see Section 8.2). For other OSs, please
refer to the readme file of the TrueFFS driver.
If DiskOnChip Millennium Plus is configured as a flash disk and as the system boot device, it contains the boot
loader, an OS image and a file system. In such a configuration, DiskOnChip Millennium Plus can serve as the only
non-volatile device on board. Refer to Section 8.3.2 for further information on boot replacement.
8.2
When used in PC compatible platforms, DiskOnChip Millennium Plus is connected to an 8KB memory window in
the BIOS expansion memory range, typically located between 0C8000H to 0EFFFFH. During the boot process, the
BIOS loads the TrueFFS firmware into the PC memory and installs DiskOnChip as a disk drive in the system. When
the operating system is loaded, DiskOnChip is recognized as a standard disk. No external software is required to
boot from DiskOnChip.
Figure 17 illustrates the location of the DiskOnChip Millennium Plus memory window in the PC memory map.
After reset, the BIOS code first executes the Power On Self-Test (POST) and then searches for all expansion ROM
devices. When DiskOnChip Millennium Plus is found, the BIOS code executes from it the IPL (Initial Program
Loader) code, located in the XIP portion of the Programmable Boot Block. This code loads the TrueFFS driver into
system memory, installs DiskOnChip Millennium Plus as a disk in the system, and then returns control to the BIOS
code. The operating system subsequently identifies DiskOnChip Millennium Plus as an available disk. TrueFFS
responds by emulating a hard disk.
From this point onward, DiskOnChip Millennium Plus appears as a standard disk drive. It is assigned a drive letter
and can be used by any application, without any modifications to either the BIOS set-up or the autoexec.bat/
config.sys files. DiskOnChip Millennium Plus can be used as the only disk in the system, with or without a floppy
drive, and with or without hard disks.
42
Booting from DiskOnChip Millennium Plus
Introduction
Boot Procedure in PC Compatible Platforms
Figure 17: DiskOnChip Millennium Plus Memory Window in PC Memory Map
0FFFFFH
0B0000H
0C8000H
0F0000H
Data Sheet, Rev. 1.7
Extended Memory
DiskOnChip
Display
BIOS
RAM
1M
640k
0
8k
DiskOnChip Millennium Plus 16/32/64MByte
93-SR-002-03-8L