MD4331-d1G-MECH M-Systems Inc., MD4331-d1G-MECH Datasheet - Page 37

• Manufacturer Part Number: MD4331-d1G-MECH
• Description: Mobile Diskonchip G3 Data Sheet
• Manufacturer: M-Systems Inc.

3.10
Mobile DiskOnChip G3 512Mb consists of two 256Mb flash planes that consist of 1024 blocks
each, organized in 64 pages, as follows:
•
•
Parallel Multi-Plane Access
The two 256Mb flash planes operate in parallel, thereby providing a true 32-bit internal data bus
and four times the read, write and erase performance. Two pages on different planes can be
concurrently read or written if they have the same offset within their respective units, even if the
units are unaligned.
Bad units are mapped individually on each plane by enabling unaligned unit access, as shown in
Figure 14. Good units can therefore be aligned or unaligned, minimizing the effects of bad units on
the media. Without this capability, a bad unit in one plane would cause a good unit in the second
plane to be tagged as a bad unit, making it unusable. This customized method of bad unit handling
for two planes enhances data reliability without adversely affecting performance.
34
Page – Each page contains 512 bytes of user data and a 16-byte extra area that is used to store
flash management and EDC/ECC signature data, as shown in Figure 12.
Block – Each block contains 64 pages (total of 256Kb), as shown in Figure 13. A block is the
minimal unit that can be erased, and is sometimes referred to as an erase block.
Note: Since the device works with multiple planes, the operational block size is 512Kb, as
Flash Architecture
described in the next section.
512 Bytes
Figure 12: Page Structure
Figure 13: Block Structure
512 Bytes
Data Sheet, Rev. 1.0
User Data
16 Bytes
Flash Management &
ECC/EDC Signature
16 Bytes
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Mobile DiskOnChip G3
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