Charles Manning！
      sorry to border you with that silly question! I found the answer just one day 
after I send out the question.  I am miss leading by the old doc, it say the close 
function is the only way to sync the file data to flash.
      Thanks' for your goodness anyway!
	

======= 2009-06-19 10:54:08 您在来信中写道：=======

>Hello
>
>Sorry about taking long to answer this. Unfortunately this ended up in my spam 
>folder.
>
>
>On Monday 01 June 2009 18:16:37 杨标(Vinge) wrote:
>> Hi all:
>> 	I just port yaff2 to ucos in direct mode with a 2k page 512m nand flash.
>> But as user of my device like to just shutdown the power. yaffs2 file
>> system is most likey not been unmount!
>
>> Is there a method to sync cache to 
>> nand? Or how can I just provent lost the cache data to be lost in poweroff?
>> Should I close the file every time after write to it?
>
>If you close a file then it will be fully flushed to flash.
>yaffs_flush() will also flush the file without closing it.
>
>> Or event unmount and remount the dev?
>
>You do not need to do that.
>
>-- Charles

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