My ip of tutorial of hls_m_axi_example doesn't work

I used pynq-z2(vivado 2018.3 and vivado hls 2018.3) and try the tutorial PYNQ_tutorials/hls_m_axi at master · cathalmccabe/PYNQ_tutorials ( the board.
I followed every step of the tutorial ,but it seems like the ip doesn’t work.The same matter happened on my pynq-zu board.So I wonder is there any step of mine went wrong?
I hope somebody can help me.
source code:

block design:


I notice the AP_DONE is always 1.It make me confused.

H @wawaji0327,

You are starting the IP before you set up the buffer address, try running the code in cell 7 after the code in cell 8.