关于以下程序,下列说法中正确的是reg [7:0] CntDis;always@(posedge Clk_50M) beginif ( Cnt30 > 29)beginCntDis[7:4] <= 3;CntDis[3:0] <= Cnt30 - 30;endelse if ( Cnt30 > 19)beginCntDis[7:4] <= 2;CntDis[3:0] <= Cnt30 - 20;endelse if ( Cnt30 > 9)beginCntDis[7:4] <= 1;CntDis[3:0] <= Cnt30 - 10;endelseCntDis <= Cnt30;end