KM29W040AT, KM29W040AIT

FLASH MEMORY

10

Error in program or erase operation

The device may fail during a program or erase operation.

The following possible failure modes should be considered when implementing a highly reliable system.

KM29W040A Technical Notes(Continued)

Failure Mode

Detection and Countermeasure sequence

Block

Erase Failure

Read after Erase --> Block Replacement

Frame

Program Failure

Status Read after Program --> Block Replacement

Single Bit

Program Failure

("1" --> "0")

Block Verify after Program --> Block Replacement

Block Replacement

When the error happens in Block "A", try to reprogram the

data into another Block "B" by reloading from an external

buffer. Then, prevent further system access to Block

"A"(by creating a "bad block" table or other appropriate

scheme.)

During Program operation ;

During Erase operation ;

When the error occurs after an erase operation, prevent future accesses to this bad block

(again by creating a table within the system or other appropriate scheme.)

Buffer

memory

error occurs

Block A

Block B