HDL Coder does not support Moving Maximum block in DSP System Toolbox out of the box. Consider using the attached model built using HDL Coder supported set of basic blocks.
If you want to do some logic on the input sample you can pipe it explicitly as shown below.
If you are piping the input sample as the first sample you could just use the block option.
The Tapped Delay has the option to directly Include the Input in its output vector. No need for Concat block if there is no additional logic on the input signal.
Synthesis Results for default Kintex7 settings:
