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sample1:<br />引用:<br />always @(ilut_index[7:0])<br />begin<br />if(ilut_index[7]) begin<br /> ron = 1;<br /> end<br />else if(ilut_index[6]) begin<br /> ron = 1; <br />end <br />else if(ilut_index[5]) begin<br /> ron = 1; <br />end<br />else if(ilut_index[4]) begin<br /> ron = 1;<br />end<br />else if(ilut_index[3]) begin<br /> ron = 1; <br />end <br />else if(ilut_index[2]) begin<br /> ron = 1; <br />end<br />else if(ilut_index[1]) begin<br /> ron = 1; <br />end<br />else begin<br /> ron = 0; <br />end<br />end<br />sample2:<br />引用:<br />always @(ilut_index[7:0])<br />begin<br />if(ilut_index[7] == 1'b1) begin<br /> ron = 1;<br /> end<br />else if(ilut_index[7:6] == 2'b01) begin<br /> ron = 1; <br />end <br />else if(ilut_index[7:5] == 3'b001) begin<br /> ron = 1; <br />end<br />else if(ilut_index[7:4] == 4'b0001) begin<br /> ron = 1;<br />end<br />else if(ilut_index[7:3] == 5'b00001) begin<br /> ron = 1; <br />end <br />else if(ilut_index[7:2] == 6'b000001) begin<br /> ron = 1; <br />end<br />else if(ilut_index[7:1] == 7'b0000001) begin<br /> ron = 1; <br />end<br />else begin<br /> ron = 0; <br />end<br />end<br />sample3:<br />引用:<br />always @(ilut_index[7:0])<br />begin<br />if(ilut_index[7] == 1'b1) begin<br /> ron = 1;<br /> end<br />if(ilut_index[7:6] == 2'b01) begin<br /> ron = 1; <br />end <br />if(ilut_index[7:5] == 3'b001) begin<br /> ron = 1; <br />end<br />if(ilut_index[7:4] == 4'b0001) begin<br /> ron = 1;<br />end<br />if(ilut_index[7:3] == 5'b00001) begin<br /> ron = 1; <br />end <br />if(ilut_index[7:2] == 6'b000001) begin<br /> ron = 1; <br />end<br />if(ilut_index[7:1] == 7'b0000001) begin<br /> ron = 1; <br />end<br />else begin<br /> ron = 0; <br />end<br />end<br /><br />sample4:<br />always @(ilut_index[7:0])<br />begin<br />if((ilut_index[7] == 1'b1) ||<br /> (ilut_index[7:6] == 2'b01) ||<br /> (ilut_index[7:5] == 3'b001) || <br /> (ilut_index[7:4] == 3'b0001) ||<br /> (ilut_index[7:3] == 3'b00001) ||<br /> (ilut_index[7:2] == 3'b000001) ||<br /> (ilut_index[7:1] == 3'b0000001) begin<br /> ron = 1;<br /> end<br /> else begin<br /> ron = 0;<br /> end<br /> end<br />sample5:<br />引用:<br />always @(ilut_index[7:0])<br />begin<br />casex (ilut_index[7:0])<br />8'b1xxx_xxxx : ron = 1;<br />8'b01xx_xxxx : ron = 1;<br />8'b001x_xxxx : ron = 1;<br />8'b0001_xxxx : ron = 1;<br />8'b0000_1xxx : ron = 1;<br />8'b0000_01xx : ron = 1;<br />8'b0000_001x : ron = 1;<br />default : ron = 0;<br />endcase<br />end<br />sample6:<br />引用:<br />always @(ilut_index[7:0])<br />begin<br />casex (ilut_index[7:0])<br />8'b1xxx_xxxx ,<br />8'b01xx_xxxx ,<br />8'b001x_xxxx , <br />8'b0001_xxxx ,<br />8'b0000_1xxx ,<br />8'b0000_01xx ,<br />8'b0000_001x : begin<br /> ron = 1;<br />end<br />default: ron = 0;<br />endcase<br />end<br />上面代码等效<br />问题：<br /> 1.请问上面几种风格优略如何？<br /> 2.从综合角度，速度及门数方面有没区别，请作一比较？ |
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