MD3331-D64-V3 M-Systems Inc., MD3331-D64-V3 Datasheet - Page 43

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

The drive letter assigned depends on how DiskOnChip Millennium Plus is used in the system, as follows:
8.3
8.3.1 PC Architectures
In current PC architectures, the first CPU fetch (after reset is negated) is mapped to the boot device area, also known
as the reset vector. The reset vector in PC architectures is located at address FFFF0, by using a Jump command to
the beginning of the BIOS chip (usually F0000 or E0000). The CPU executes the BIOS code, initializes the
hardware and loads DiskOnChip Millennium Plus software using the BIOS expansion search routine (e.g. D0000).
Refer to Section 8.2 for a detailed explanation on the boot sequence in PC compatible platforms.
DiskOnChip Millennium Plus implements both disk and boot functions when it replaces the BIOS chip. To enable
this, DiskOnChip Millennium Plus requires a location at two different addresses:
This means that the CS# signal must be remapped between two different addresses. For further information on how
to achieve this, refer to application note AP-DOC-047, Designing DiskOnChip as a Flash Disk and Boot Device
Replacement.
8.3.2 Non-PC Architectures
In non-PC architectures, the boot code is executed from a boot ROM, and the drivers are usually loaded from the
storage device.
When using DiskOnChip Millennium Plus as the system boot device, the CPU fetches the first instructions from the
DiskOnChip Millennium Plus Programmable Boot Block, which contains the IPL. Since in most cases this block
cannot hold the entire boot loader, the Initial Program Loader (IPL) runs minimum initialization, after which the
Secondary Program Loader (SPL) is copied to RAM from flash. The remainder of the boot loader code then runs
from RAM.
The IPL and SPL are located in a separate (binary) partition on DiskOnChip Millennium Plus, and can be hardware
protected if required.
For further information on software boot code implementation, refer to application notes AP-DOC-070, Writing an
IPL for DiskOnChip Millennium Plus 32MB, and AP-DOC-044, Writing an IPL for DiskOnChip Millennium Plus
16MB.
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Boot Replacement
If DiskOnChip Millennium Plus is used as the only disk in the system, the system boots directly from it and
assigns it drive C.
If DiskOnChip Millennium Plus is used with other disks in the system:
o
o
If DiskOnChip Millennium Plus is used as the OS boot device when configured as drive C, it must be
formatted as a bootable device by copying the OS files onto it. This is done by using the SYS command
when running DOS.
After power-up, DiskOnChip Millennium Plus must be mapped in F segment, so that the CPU fetches the
reset vector from address FFFF0, where DiskOnChip Millennium Plus is located.
After the BIOS code is loaded into RAM and starts execution, DiskOnChip Millennium Plus must be
reconfigured to be located in the BIOS expansion search area (e.g. D0000) so it can load the TrueFFS
software.
DiskOnChip Millennium Plus can be configured as the last drive (the default configuration). The
system assigns drive C to the hard disk and drive D to DiskOnChip Millennium Plus.
Alternatively, DiskOnChip Millennium Plus can be configured as the system’s first drive. The system
assigns drive D to the hard disk and drive C to DiskOnChip Millennium Plus.
Data Sheet, Rev. 1.7
DiskOnChip Millennium Plus 16/32/64MByte
93-SR-002-03-8L