Realization of FPGA Rotary ENCODER

Module Pmodenc (
Class
Rst_n,
A
B
BTN,
A_debounce,
B_debounce,
Btn_debounce,
Rotary_right,
Rotary_left
Led
);

Input wire clk,rst_n;
Input wire a,b,btn;
Output wire a_debounce,b_debounce,btn_debounce;
Output wire rotary_right,rotary_left;
Output wire [5:0]led;

Reg CLK_10MS;
reg [31:0]count;

Reg A_REG,A_REG0;
Reg B_REG,B_REG0;
Reg BTN_REG,BTN_REG0;
Wire a_debounce;
Wire b_debounce;
Wire btn_debounce;

Reg A_debounce_reg;
Reg B_debounce_reg;
Wire A_pos,a_neg;
Wire B_pos,b_neg;

Reg Rotary_right;
Reg Rotary_left;

Reg Rotary_right_reg,rotary_left_reg;
Wire Rotary_right_pos,rotary_left_pos;
Wire rotary_event;

reg [5:0]shift_d;

[Email protected] (Posedge Clk,negedge rst_n) begin
if (!rst_n) begin
Count <= 0;
clk_10ms <= 1 ' b0;
End
ELSE begin
if (Count < d24_999) begin//10ms Shake, 25MCLK
Count <= count + 1 ' B1;
clk_10ms <= 1 ' b0;
End
ELSE begin
Count <= 0;
clk_10ms <= 1 ' B1;
End
End
End

[Email protected] (Posedge Clk,negedge rst_n) begin
if (!rst_n) begin
A_reg <= 1 ' B1;
A_reg0 <= 1 ' B1;
B_reg <= 1 ' B1;
B_reg0 <= 1 ' B1;
Btn_reg <= 1 ' b0;
Btn_reg0 <= 1 ' b0;
End
ELSE begin
if (clk_10ms) begin
A_reg <= A;
A_reg0 <= A_reg;
B_reg <= B;
B_reg0 <= B_reg;
Btn_reg <= BTN;
Btn_reg0 <= Btn_reg;
End
End
End

Assign a_debounce = a_reg0 && a_reg && A;
Assign b_debounce = b_reg0 && b_reg && B;
Assign btn_debounce = btn_reg0 && btn_reg && btn;//make pulse rising edge after shaking

[Email protected] (Posedge Clk,negedge rst_n) begin
if (!rst_n) begin
A_debounce_reg <= 1 ' B1;
B_debounce_reg <= 1 ' B1;
End
ELSE begin
A_debounce_reg <= a_debounce;
B_debounce_reg <= b_debounce;
End
End

Assign A_pos =! A_debounce_reg && a_debounce;
Assign B_pos =! B_debounce_reg && b_debounce;

Assign A_neg = A_debounce_reg &&! A_debounce;
Assign B_neg = B_debounce_reg &&! B_debounce;

[Email protected] (Posedge Clk,negedge rst_n) begin
if (!rst_n) begin
Rotary_right <= 1 ' B1;
Rotary_left <= 1 ' B1;
End
ELSE begin
if (A_pos &&!) B_debounce) begin//a If B is low, the rotary encoder is turned to the right
Rotary_right <= 1 ' B1;
End

if (A_pos && b_debounce) begin//a rising edge when B is low, the rotary encoder turns left
Rotary_left <= 1 ' B1;
End

if (A_neg && b_debounce) begin//a The falling Edge B is high, turn right to end
Rotary_right <= 1 ' b0;
End

if (A_neg &&!) b_debounce) begin//a The falling edge of B is low, then turn to the left end
Rotary_left <= 1 ' b0;
End
End
End

Assign rotary_left = Rotary_left;
Assign rotary_right = Rotary_right;
[Email protected] (Posedge Clk,negedge rst_n) begin
if (!rst_n) begin
Rotary_right_reg <= 1 ' B1;
Rotary_left_reg <= 1 ' B1;
End
ELSE begin
Rotary_right_reg <= rotary_right;
Rotary_left_reg <= Rotary_left;
End
End

Assign Rotary_right_pos =!rotary_right_reg && rotary_right;
Assign Rotary_left_pos =!rotary_left_reg && rotary_left;//Shake

Assign rotary_event = Rotary_right_pos | | rotary_left_pos;//rotation flag bit

[Email protected] (Posedge Clk,negedge rst_n) begin
if (!rst_n)
Shift_d <= 6 ' b111_110;
else if (rotary_event) begin
if (Rotary_right_pos)
Shift_d <= {shift_d[0],shift_d[5:1]};
if (Rotary_left_pos)
Shift_d <= {shift_d[4:0],shift_d[5]};
End
End

Assign LED = left-to-right test module for shift_d;//lamp

Endmodule

Principle, you can refer to the http://www.eeboard.com/bbs/forum.php?mod=viewthread&tid=45184&highlight=%E5%B0%8F%E8%84 of this great God. %9a%e4%b8%ab

Realization of FPGA Rotary ENCODER