题解 | #用优先编码器①实现键盘编码电路#
用优先编码器①实现键盘编码电路
https://www.nowcoder.com/practice/03b8c5837d7f406797b4a57358057ef7
`timescale 1ns/1ns
module encoder_0(
input [8:0] I_n ,
output reg [3:0] Y_n
);
always @(*)begin
casex(I_n)
9'b111111111 : Y_n = 4'b1111;
9'b0xxxxxxxx : Y_n = 4'b0110;
9'b10xxxxxxx : Y_n = 4'b0111;
9'b110xxxxxx : Y_n = 4'b1000;
9'b1110xxxxx : Y_n = 4'b1001;
9'b11110xxxx : Y_n = 4'b1010;
9'b111110xxx : Y_n = 4'b1011;
9'b1111110xx : Y_n = 4'b1100;
9'b11111110x : Y_n = 4'b1101;
9'b111111110 : Y_n = 4'b1110;
default : Y_n = 4'b1111;
endcase
end
endmodule
module key_encoder(
input [9:0] S_n ,
output wire[3:0] L ,
output wire GS
);
wire[3:0]temp;
reg [3:0]out;
reg g;
encoder_0 u0(.I_n(S_n[9:1]),.Y_n(temp));
always @(*)begin
case(temp)
4'b1111: begin g= 1'b0;
if(S_n[0])
begin
g= 1'b0;
out= 0;
end
else
begin
g= 1'b1 ;
out= 0;
end
end
4'b0110: begin out= 9; g= 1'B1; end
4'b0111: begin out= 8; g= 1'B1; end
4'b1000: begin out= 7; g= 1'B1; end
4'b1001: begin out= 6; g= 1'B1 ;end
4'b1010: begin out= 5; g= 1'B1 ;end
4'b1011: begin out= 4; g= 1'B1 ;end
4'b1100: begin out= 3; g= 1'B1 ;end
4'b1101: begin out= 2; g= 1'B1 ;end
4'b1110: begin out= 1; g= 1'B1 ;end
endcase
end
assign GS=g;
assign L=out;
endmodule
