The AXI DataMover has two clock inputs for each of the MM2S and
S2MM blocks for a total of four clock inputs. The m_axi_mm2s_aclk is the main synchronizing clock for the MM2S block. This clock
synchronizes both the associated AXI4 interface and Stream interface. The second clock for the
MM2S element is m_axis_mm2s_cmdsts_aclk. This clock is used
only when MM2S is configured in asynchronous mode. When used, it synchronizes the user sides
of the Command and Status interfaces.
The S2MM block has identical clocking schemes as the MM2S block but with two different
clocks, the m_axi_axi_s2mm_aclk and
m_axis_s2mm_cmdsts_awclk.