Which 4390 Hardware are you using?
I'm using the SPIL SB-WM-N04 SiP on a custom board, and SB-WM-N03 on a EVM.
Okay, I assume you are not going to answer this. Is there a more complete reference manual (document number?) I shall request through my distributor?
Please check with your distributor for the datasheet.
The 4390 you have is not available to everyone, it is only available to select partners. For this reason support for this part is outside the scope of this Forum. You should contact SPIL for support or the distributor who provided this to you. Feel free to send me a private message to discuss more.