Hi Dragos，
Thank you for your quick reply .I then look into the main.c and I think the default DAC source is DATA_SEL_DMA, and the problem didn't sovle either . Can you explain why?
the main .c writes:
#ifdef DAC_DMA
dac_init(ad9361_phy, DATA_SEL_DMA);
#else
dac_init(ad9361_phy, DATA_SEL_DDS);
#endif
YOURS,
wang zhi