Question

The possible states of the FSM can also be specified with a pragma that includes the enumeration name:

parameter /* tool enum enumeration_name */
S0 = 0,
s1 = 1,
s2 = 2,
s3 = 3;

Put this pragma immediately after the keyword parameter, unless a bit-width for the parameters is used, in which case, specify the pragma immediately after the bit-width:

parameter [1:0] /* tool enum enumeration_name */
S0 = 0,
s1 = 1,
s2 = 2,
s3 = 3;