define??SCAN

module??key_scan(

clk? ? ,

rst_n??,

key_col, //鍵盤列輸入

key_row, //鍵盤行輸出

key_num, //指示哪一個按鍵按下，用0~15指示

key_vld??//按下有效指示信號，其為1表示按下一次。

);

parameter? ?? ?KEY_W? ? =? ?4 ;

parameter? ?? ?COL? ?? ?=? ?0 ;

parameter? ?? ?ROW? ?? ?=? ?1 ;

parameter? ?? ?DLY? ?? ?=? ?2 ;

parameter? ?? ?FIN? ?? ?=? ?3 ;

parameter? ?? ?COL_CNT??=? ?16;

parameter? ?? ?TIME_20MS=? ?1000000;

//輸入信號定義

input? ?? ?? ?? ?? ?clk? ? ;

input? ?? ?? ?? ?? ?rst_n??;

input??[3:0]? ?? ???key_col;

//輸出信號定義

output? ?? ?? ?? ???key_vld;

output[3:0]? ?? ?? ?key_num;

output[KEY_W-1:0]? ?key_row;

//輸出信號reg定義

reg? ?[3:0]? ?? ?? ?key_num;

reg? ?[KEY_W-1:0]? ?key_row;

reg? ?? ?? ?? ?? ???key_vld;

reg? ?[ 3:0]? ?? ???key_col_ff0? ?;

reg? ?[ 3:0]? ?? ???key_col_ff1? ?;

reg? ?[ 1:0]? ?? ???key_col_get? ?;

reg? ?? ?? ?? ?? ???shake_flag? ? ;

reg? ?? ?? ?? ?? ???shake_flag_ff0;

reg? ?[ 3:0]? ?? ???state_c? ?? ? ;

reg? ?[19:0]? ?? ???shake_cnt? ???;

reg? ?[ 3:0]? ?? ???state_n? ?? ? ;

reg? ?[ 1:0]? ?? ???row_index? ???;

reg? ?[15:0]? ?? ???row_cnt? ?? ? ;

reg? ?[ 2:0]? ?? ???x? ?? ?? ?? ? ;

always??@(posedge clk or negedge rst_n)begin

if(rst_n==1'b0)begin

key_col_ff0 <= 4'b1111;

key_col_ff1 <= 4'b1111;

end

else begin

key_col_ff0 <= key_col? ? ;

key_col_ff1 <= key_col_ff0;

end

end

always??@(posedge clk or negedge rst_n)begin

if(rst_n==1'b0)begin

shake_cnt <= 0;

end

else if(add_shake_cnt)begin

if(end_shake_cnt)

shake_cnt <= 0;

else

shake_cnt <= shake_cnt + 1;

end

else begin

shake_cnt <= 0;

end

end

assign??add_shake_cnt = key_col_ff1!=4'hf && shake_flag==0;

assign??end_shake_cnt = add_shake_cnt && shake_cnt==TIME_20MS-1;

always??@(posedge clk or negedge rst_n)begin

if(rst_n==1'b0)begin

shake_flag <= 0;

end

else if(end_shake_cnt) begin

shake_flag <= 1'b1;

end

else if(key_col_ff1==4'hf) begin

shake_flag <= 1'b0;

end

end

`ifdef SCAN

always??@(posedge clk or negedge rst_n)begin

if(rst_n==1'b0)begin

state_c <= COL;

end

else begin

state_c <= state_n;

end

end

always??@(*)begin

case(state_c)

COL: begin

if(col2row_start)begin

state_n = ROW;

end

else begin

state_n = state_c;

end

end

ROW: begin

if(row2dly_start)begin

state_n = DLY;

end

else begin

state_n = state_c;

end

end

DLY :??begin

if(dly2fin_start)begin

state_n = FIN;

end

else begin

state_n = state_c;

end

end

FIN: begin

if(fin2col_start)begin

state_n = COL;

end

else begin

state_n = state_c;

end

end

default: state_n = COL;

endcase

end

assign??col2row_start = state_c==COL && end_shake_cnt;

assign??row2dly_start = state_c==ROW && end_row_index;

assign??dly2fin_start = state_c==DLY && end_row_index;

assign??fin2col_start = state_c==FIN && key_col_ff1==4'hf;

always??@(posedge clk or negedge rst_n)begin

if(rst_n==1'b0)begin

key_row <= 4'b0;

end

else if(state_c==ROW)begin

key_row <= ~(1'b1 << row_index);

end

else begin

key_row <= 4'b0;

end

end

always??@(posedge clk or negedge rst_n)begin

if(rst_n==1'b0)begin

row_cnt <= 0;

end

else if(add_row_cnt) begin

if(end_row_cnt)

row_cnt <= 0;

else

row_cnt <= row_cnt + 1;

end

end

assign add_row_cnt = state_c==ROW || state_c==DLY;

assign end_row_cnt = add_row_cnt && row_cnt==COL_CNT-1;

always??@(posedge clk or negedge rst_n)begin

if(rst_n==1'b0)begin

row_index <= 0;

end

else if(add_row_index) begin

if(end_row_index)

row_index <= 0;

else

row_index <= row_index + 1;

end

end

assign add_row_index = end_row_cnt;

assign end_row_index = add_row_index && row_index==x-1;

always??@(*)begin

if(state_c==ROW)

x = 4;

else

x = 1;

end

always??@(posedge clk or negedge rst_n)begin

if(rst_n==1'b0)begin

key_col_get <= 0;

end

else if(col2row_start) begin

if(key_col_ff1==4'b1110)

key_col_get <= 0;

else if(key_col_ff1==4'b1101)

key_col_get <= 1;

else if(key_col_ff1==4'b1011)

key_col_get <= 2;

else

key_col_get <= 3;

end

end

always??@(posedge clk or negedge rst_n)begin

if(rst_n==1'b0)begin

key_num <= 0;

end

else if(state_c==ROW && end_row_cnt)begin

key_num <= {row_index,key_col_get};

end

else begin

key_num <= 0;

end

end

always??@(posedge clk or negedge rst_n)begin

if(rst_n==1'b0)begin

key_vld <= 1'b0;

end

else if(state_c==ROW && end_row_cnt && key_col_ff1[key_col_get]==1'b0)begin

key_vld <= 1'b1;

end

else begin

key_vld <= 1'b0;

end

end

`else

always??@(posedge clk or negedge rst_n)begin

if(rst_n==1'b0)begin

key_vld <= 0;

end

else begin

key_vld <= end_shake_cnt;

end

end

always??@(*)begin

key_num = 0;

end

`endif

endmodule