always @(x or currentState)
begin
case (x)
2'b00 :
case (currentState)
S0,S1 : nextState <= S0;
S2 : nextState <= S2;
S3 : nextState <= S3;
endcase
2'b01 : ...
default : ….
endcase
end
S0
S3
S1
S2
01/0
00/0
1x/0
00/1
01/0
00/0
01/1
00/1
1x/1
01/1
1x/1
1x/0
古い考え方
非推奨