MD3331-D64-V3-X SanDisk, MD3331-D64-V3-X Datasheet - Page 43

• Manufacturer Part Number: MD3331-D64-V3-X
• Manufacturer: SanDisk
• Type: Flash Diskr

Specifications of MD3331-D64-V3-X

• Density: 64MByte
• Operating Supply Voltage (typ): 3.3V
• Operating Temperature (min): -40C
• Operating Temperature (max): 85C
• Package Type: FBGA
• Mounting: Surface Mount
• Pin Count: 69
• Operating Temperature Classification: Industrial
• Operating Supply Voltage (min): 2.5V
• Operating Supply Voltage (max): 3.6V
• Programmable: Yes
• Lead Free Status / Rohs Status: Not Compliant

From this point onward, Mobile DiskOnChip 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. Mobile DiskOnChip Plus can be used as the only disk in the
system, with or without a floppy drive, and with or without hard disks.
The drive letter assigned depends on how Mobile DiskOnChip 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 Mobile DiskOnChip 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.
Mobile DiskOnChip Plus implements both disk and boot functions when it replaces the BIOS chip.
To enable this, Mobile DiskOnChip 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.
43
If Mobile DiskOnChip Plus is used as the only disk in the system, the system boots directly
from it and assigns it drive C.
If Mobile DiskOnChip Plus is used with other disks in the system:
o
o
If Mobile DiskOnChip 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, Mobile DiskOnChip Plus must be mapped in F segment, so that the CPU
fetches the reset vector from address FFFF0, where Mobile DiskOnChip Plus is located.
After the BIOS code is loaded into RAM and starts execution, Mobile DiskOnChip Plus must
be reconfigured to be located in the BIOS expansion search area (e.g. D0000) so it can load the
TrueFFS software.
Boot Replacement
Mobile DiskOnChip Plus can be configured as the last drive (the default configuration).
The system assigns drive C to the hard disk and drive D to Mobile DiskOnChip Plus.
Alternatively, Mobile DiskOnChip Plus can be configured as the system’s first drive. The
system assigns drive D to the hard disk and drive C to Mobile DiskOnChip Plus.
Data Sheet, Rev. 1.8
Mobile DiskOnChip Plus 16/32MByte
95-SR-000-10-8L