Does the dac to mem example in 9009 no-os project should provide data to RX interface external such as by signal genetator? For when I connect TX1 with RX1 and then cancel comment of both DMA example and adc to mem example，and add ILA in vivado，I just see waveform appear in the output of tx_dma, but nothing can be found in output of rx_dma（the value of 0）?
Any help should be appreciated!!
You don't need a signal generator. Data is sent over TX1 using DMA from a sine LUT table. If you physically loopback RX1 and TX1 you will see the waveform at RX1.