That is a interesting question, But I think the extra flash can only be used for data and not program. the size of program flash is still only 65k. I think that also means it is up to the user to make sure the data usage is not exceeded.
Thank's for your response IIeung.
Then, you mean that you can storage data with the functions of CyWriteRowConfig(Writes the ECC portion of a Flash row), for example, but this data can't be used into program memory, right? So you still having 64KB of memory program Flash.
I remember to have read that the ECC could be used as configuration data (only). Isn't there the choice to put tem into ECC (just one line below)?
All your comments are absolutely right. You get 64K of Flash in the program space. The other 8K of Flash is either used as ECC or is used to store configuration data. You do not have the liberty to use it as normal Flash due to various reasons.