mcode block in system generator

[prashanthi999]

i have been implementing the sequence detection of 1101 in system generator using "mcode" block that performs state machines , i have understand the other things in code, but could not get the meaning of this sentence "persistent state , state = x1_state(start, {x1unsigned, 2,0});" can anybody tell what the meaning of that sentence

the whole code is of 1101 pattern detection

function matched = detect_1101(d_in)
start= 0;
found1=1;
found11=2;
found110=3;
   persistent state , state = x1_state(start, {x1unsigned, 2,0});
  matched = 0;
  
  
  switch state 
      
      case start
          if d_in ==1
              state = found1;
          else
              state =start;
          end
          
      case found1
          if d_in ==1
              state = found11 ;
          else
              state =start;
          end    
      case found11
          if d_in ==0
              state = found110;
          else
              state =found11;
          end
          
       case found110
          if d_in ==1
              state = found1;
              matched = 1;
          else
              state = start;
          end    
      otherwise
          state = start;
  end
  end