why the adv212 still keep dreq low,when I have sent all code data into adv212?

HI:

     my 212 setting  is described below:

     hipi,32bit,decode mode,dma0 is attached to  the code fifo,dma1 is attached to the pixel fifo;

     EDMOD0 = 0x00d30000;//code fifo,Burst Transfer Dreq/Dack DMA mode,burst length = 64

     EDMOD1 = 0x00d10000;//pixel fifo,Burst Transfer Dreq/Dack DMA mode,burst length = 64

     XTOT = 4096<<16;

     YTOT = 128<<16;

     PMODE1=0x1140000;//4x8 single component

     PMODE2=0x00100000;//

     VMODE =0x00100000;//decode

     decode parameter setting;

     address;0x57f00,data = 0x04010003;//Custom specific,precison=10bit,

     address:0x57f04,data = 0x01000000;

     address:0x57f08,data = 0x00000000;

     address:0x57f0c,data = 0x00000000;

     I'm not sure that whether PMODE1 is set properly ,because I only konw that the image'size is 4096x128,precision is 10 bit

     my  progress:

     ADV 212 's initialized ok! I have read ID=0xffa2;then I found an odd thing:

     dreq0 is asserted to be low for only 8 times;In other words,I just sent 8x64 32bits,then no data can be sent any more;

     after a few tests, I found that ,after initialization,if I set EIRQFLG =0xffff, the adv212 will assert dreq0  more than 8 times;

     but there comes another problem:  after all code data are sent into the code fifo,adv212 is still asserting dreq0;and dreq1 is not comming asserted;

     I have tested three chips,the same problems exist on all chips;so the hardware is ok!

     after several days' work,there's no more progress;

     i have  analyzed a few possible causes:

     (1)  my adv212's setting may have some faults,Especially PMODE1 and the decode parameters, i know nothing about the wavelet,jpeg,etc

     (2)  my code data might have some problem