Chapter 1 – Introduction
Revision 3.1
SanDisk iNAND Product Manual
© 2006 SanDisk Corporation
1-3
12/07/06
1.5 Functional
Description
The SanDisk iNAND contains a high-level, intelligent subsystem as shown in Figure 1-1.
This intelligent (microprocessor) subsystem provides many capabilities not found in other
types of memory cards. These capabilities include:
•
Host independence from details of erasing and programming flash memory
•
Sophisticated system for managing defects (analogous to systems found in magnetic
disk drives)
•
Sophisticated system for error recovery including a powerful ECC
•
Power management for low power operation
1.6 Technology
Independence
The 512-byte sector size of the SanDisk iNAND is the same as that in an IDE magnetic
disk drive. To write or read a sector (or multiple sectors), the host software simply issues a
read or write command to the card. The command contains the address and number of
sectors to write or read. The host software then waits for the command to complete.
The host software does not get involved in the details of how the flash memory is erased,
programmed or read. This is extremely important because flash devices are expected to get
increasingly complex in the future. Because iNAND use an intelligent on-board controller,
host system software will not need to be updated as new flash memory evolves. In other
words, systems that support iNAND technology today will be able to access future SanDisk
devices built with new flash technology without having to update or change host software.
