Why is this an issue?

To improve readability, default should be the last item of a case statement.

How to fix it

Move the default clause to the end of the case statement.

Code examples

Noncompliant code example

unique casez (select)
  default: operand = '0; // Noncompliant: Should be moved to the end
  3'b000: operand = accum0 >> 0;
  3'b001: operand = accum0 >> 1;
  3'b010: operand = accum1 >> 0;
  3'b011: operand = accum1 >> 1;
  3'b1??: operand = regfile[select[1:0]];
endcase

Compliant solution

unique casez (select)
  3'b000: operand = accum0 >> 0;
  3'b001: operand = accum0 >> 1;
  3'b010: operand = accum1 >> 0;
  3'b011: operand = accum1 >> 1;
  3'b1??: operand = regfile[select[1:0]];
  default: operand = '0;
endcase

Resources

Related rules