MD3331-D32-V3Q18 M-Systems Inc., MD3331-D32-V3Q18 Datasheet - Page 20

• Manufacturer Part Number: MD3331-D32-V3Q18
• Description: Mobile Diskonchip Plus 128Mbits 1.8V I/o
• Manufacturer: M-Systems Inc.

3.7
NAND flash, being an imperfect memory, requires error handling. Mobile DiskOnChip Plus implements
Reed-Solomon Error Detection Code (EDC). A hardware-generated, 6-byte error detection signature is computed
each time a page (512 bytes) is written to or read from Mobile DiskOnChip Plus.
The TrueFFS driver implements complementary Error Correction Code (ECC). Unlike error detection, which is
required on every cycle, error correction is relatively seldom required, hence implemented in software. The
combination of Mobile DiskOnChip Plus’s built-in EDC mechanism and the TrueFFS driver ensures highly reliable
error detection and correction, while providing maximum performance.
The following detection and correction capability is provided for each 512 bytes:
3.8
Mobile DiskOnChip Plus uses a two-stage pipeline mechanism, designed for maximum performance while enabling
on-the-fly data manipulation, such as read/write protection and Error Detection/Error Correction.
3.9
The Control & Status block contains registers responsible for transferring the address, data and control information
between the DiskOnChip TrueFFS driver and the flash media. Additional registers are used to monitor the status of
the flash media (ready/busy) and of the DiskOnChip controller. For further information on the Mobile DiskOnChip
Plus registers, refer to Section 6.3).
3.10 Flash Architecture
A 16MB flash bank consists of 1024 blocks organized in 32 pages, as follows:
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Error Detection Code/Error Correction Code (EDC/ECC)
Data Pipeline
Control & Status
Corrects up to two 10-bit symbols, including two random bit errors.
Corrects single bursts up to 11 bits.
Detects single bursts up to 31 bits and double bursts up to 11 bits.
Detects up to 4 random bit errors.
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 6. A page is the minimal unit for read/write
operations.
Block – Each block contains 32 pages (total of 16KB), as shown in Figure 7. A block is the minimal unit
that can be erased, and is sometimes referred to as an erase block.
512 Bytes
Figure 6: Page Structure
Data Sheet, Rev. 1.7
User Data
16 Bytes
Flash Management &
ECC/EDC Signature
Mobile DiskOnChip Plus 16/32MByte 1.8V I/O
0.5 KB
95-SR-000-10-8L