K9S2808V0M-SSB0

10

SmartMedia Technical Notes (Continued)

Program Flow Chart

Start

I/O 6 = 1 ?

Write 00h

I/O 0 = 0 ?

No

*

If ECC is used, this verification

Write 80h

Write Address

Write Data

Write 10h

Read Status Register

Write Address

Wait for tR Time

Verify Data

No

Program Completed

or R/B = 1 ?

Program Error

Yes

No

Yes

*

Program Error

Yes

: If program operation results in an error, map out

the block including the page in error and copy the

target data to another block.

*

operation is not needed.

Error in write or read operation

Over its life time, the additional invalid blocks may develop with NAND Flash memory. Refer to the qualification report for the actual

data.The following possible failure modes should be considered to implement a highly reliable system. In the case of status read fail-

ure after erase or program, block replacement should be done. To improve the efficiency of memory space, it is recommended that

the read or verification failure due to single bit error be reclaimed by ECC without any block replacement. The said additional block

failure rate does not include those reclaimed blocks.

Failure Mode

Detection and Countermeasure sequence

Write

Erase Failure

Status Read after Erase --> Block Replacement

Program Failure

Status Read after Program --> Block Replacement

Read back ( Verify after Program) --> Block Replacement

or ECC Correction

Read

Single Bit Failure

Verify ECC -> ECC Correction

ECC

: Error Correcting Code --> Hamming Code etc.

Example) 1bit correction & 2bit detection