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MoEl_4197781
Level 2
First like given
Level 2

I start using memory S25FL128L  to replace ISSI one

problem when try to read ( normal read ) all parts show no problems at first use then by time some of them  cannot be read by normal mode

then I added Mode bit reset command FFH prior  to software reset 99H ,all parts works fine

so I want to know how memory enter high performance read mode without i issue any commands for that ??

is there any way to keep memory in stranded mode without worry about changing mode it self ?

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1 Solution
MoEl_4197781
Level 2
First like given
Level 2

thanks for answering

yes all parts show working fine and after days i checked about 40 % of 40 parts show problem when i try to read fixed area in memory

i use normal read 03h followed by page address  3 bytes then read 256 bytes and then repeat send read command with next page address

before read i do software reset 66H then 99H

to solve the problem i add MBR reset  so i do reset  AS 66H FFH 99H

I want to prevent flash from entering other read mode randomly

View solution in original post

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6 Replies
SudheeshK
Moderator
Moderator First question asked 750 replies posted 500 replies posted
Moderator

Hi,

What is the read command that you use?

What is the value of mode bits that you sent during read operation?

Thanks and Regards,

Sudheesh

MoEl_4197781
Level 2
First like given
Level 2

I use  03 normal read with out mode bits

Some parts accept and some don't accept randomly

But after add MBR .mode bit reset all parts work ok

I want to prevent flash from entering other read mode randomly

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SudheeshK
Moderator
Moderator First question asked 750 replies posted 500 replies posted
Moderator

Hi,

Earlier you mentioned that there is no issue initially and it starts to happen after sometime of operation. Please correct me if I am wrong.

"all parts show no problems at first use then by time some of them  cannot be read by normal mode"

Could you please let me know the sequence of commands send to the flash device before this issue happens?

Thanks and Regards,

Sudheesh

MoEl_4197781
Level 2
First like given
Level 2

thanks for answering

yes all parts show working fine and after days i checked about 40 % of 40 parts show problem when i try to read fixed area in memory

i use normal read 03h followed by page address  3 bytes then read 256 bytes and then repeat send read command with next page address

before read i do software reset 66H then 99H

to solve the problem i add MBR reset  so i do reset  AS 66H FFH 99H

I want to prevent flash from entering other read mode randomly

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BacemD_61
Employee
50 replies posted 50 sign-ins 25 replies posted
Employee

Hello,

The S25FL128L does not go into any specific mode by itsown. It's always acting in slave mode and reacts to the received commands.

Please check the commands that were sent to the flash and also more importantly, please check the power supply voltage (VCC) stability.

There should be no power drops or big irregularities.

Here is a KBA that specifically talks about this point: 65-nm Flash Family Behavior During Voltage Irregularities - KBA219071

Best regards,

Bacem

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MoEl_4197781
Level 2
First like given
Level 2

It looks like power problem as you told I will recheck and let you know

Thanks

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