The ACLKEN pin is an active-High, synchronous clock-enable input pertaining to the AXI4-Stream interface. Setting ACLKEN Low (deasserted) halts the operation of the AXI4-Stream Bus despite rising edges on the ACLK pin. Internal states are maintained, and output signal levels are held until ACLKEN is asserted again. When ACLKEN is deasserted, core AXI4-Stream inputs are not sampled, except ARESETn , which supersedes ACLKEN .