组合逻辑代码设计

7段数码管译码器

Verilog代码：

module seg_dec(num,a_g);
input[3:0]           num;
output[6:0]          a_g;//a_g[6:0]->(a,b,c,d,e,f,g)
reg[6:0]             a_g;
always@(num)begin
    case(num)        //用case语句实现组合逻辑
    4'd0:begin a_g<=7'b111_1110;end
    4'd1:begin a_g<=7'b011_0000;end
    4'd2:begin a_g<=7'b110_1101;end
    4'd3:begin a_g<=7'b111_1100;end
    4'd4:begin a_g<=7'b011_0011;end
    4'd5:begin a_g<=7'b101_1011;end
    4'd6:begin a_g<=7'b101_1111;end
    4'd7:begin a_g<=7'b111_0000;end
    4'd8:begin a_g<=7'b111_1111;end
    4'd9:begin a_g<=7'b111_1011;end
    default:begin a_g<=7'b000_0001;end//num超出（0-9）时，用default统一处理，显示为中杠；

    endcase

end
endmodule