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- module hc83( //带进位功能的四位二进制全加器 加法器 GND:Pin12 VCC:Pin5 (与74HC283管脚排列不同)
- input [3:0] A, //被加数 Pin:1,3,8,10
- input [3:0] B, //加数 Pin:16,4,7,11
- input Cin, //进位输入 Pin13
- output [3:0] S, //和 Pin:15,2,6,9
- output Cou //进位输出 Pin14
- );
- assign {Cou,S} = A + B + Cin;
- endmodule
- module main(
- input clk, //时钟输入
- output out //256分频输出
- );
- reg [7:0] i;
- wire [7:0] j;
- wire cy; //进位标志
- hc83 U1(
- .A(i[3:0]),
- .B(4'd0),
- .Cin(1'b1),
- .S(j[3:0]),
- .Cou(cy)
- );
- hc83 U2(
- .A(i[7:4]),
- .B(4'd0),
- .Cin(cy),
- .S(j[7:4]),
- .Cou()
- );
- always @(posedge clk) begin
- i <= j;
- end
- assign out = i[7];
- endmodule
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