Renesas SH7264 User Manual

 

Section 25   NAND Flash Memory Controller 

R01UH0134EJ0400  Rev. 4.00  

 

Page 1333 of 2108 

Sep 24, 2014 

 

 

 
SH7262 Group, SH7264 Group 

The 4-symbol ECC circuit in this module is capable of correcting up to 10 bits per symbol, which 
makes a maximum of 40 bits for four symbols. However, the circuit corrects up to 32 bits because 
the data in the flash memory data area is counted as eight bits per symbol. 

Error correction pattern generation means generation of information necessary for correcting 
errors, not execution of error correction. For details, see section 25.4.6, (3) 4-Symbol ECC Error 
Correction Pattern Generation. 

The 4-symbol ECC circuit is roughly divided into three stages (figure 25.15). 

1. ECC generator 

2. Error count detector 

3. Error correction pattern generator 
 
ECC generation and error count detection can be executed continuously while error correction 
pattern generation is executed on a sector-by-sector basis. 

Register

Flash memory

External memory

4-symbol ECC 

error count

detector

4-symbol ECC circuit

This module

512 bytes (data)
 +
10 bytes  (ECC)

4-symbol ECC 

generator

4-symbol ECC 
error correction

pattern 

generator

4-symbol ECC processing result 1
4-symbol ECC processing result 2
4-symbol ECC processing result 3
4-symbol ECC processing result 4

ECC error count register

Register