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|
module debounce (
clk,
reset_n,
in,
out,
strobe
);
// This is optimized for a 25 MHz clock and the
// assumption that glitches are limited to ~2 ms
parameter ctrbits = 16;
parameter width = 1;
input clk;
input reset_n;
input [width-1:0] in;
output [width-1:0] out;
output strobe;
reg [width-1:0] out;
reg [width-1:0] strobes;
reg [ctrbits-1:0] ctr [0:width-1];
assign strobe = |strobes;
wire [width-1:0] in_q;
synchronize #(.width(width))
debounce_sync (.reset(~reset_n), .clk(clk), .d(in), .q(in_q));
genvar i;
generate
for (i = 0; i < width; i = i + 1)
begin: gen_debounce
always @(negedge reset_n or posedge clk)
if ( ~reset_n )
begin
out[i] <= 1'b0;
strobes[i] <= 1'b0;
ctr[i] <= {1'b0, {ctrbits-1{1'b0}}};
end
else
begin
strobes[i] <= 1'b0;
if ( in_q[i] )
begin
if ( &ctr[i] )
begin
out[i] <= 1'b1;
strobes[i] <= 1'b1;
end
else
ctr[i] <= ctr[i] + 1'b1;
end
else
begin
if ( ~|ctr[i] )
begin
out[i] <= 1'b0;
strobes[i] <= 1'b1;
end
else
ctr[i] <= ctr[i] - 1'b1;
end // else: !if( in[i] )
end // else: !if( ~reset_n )
end // block: gen_debounce
endgenerate
endmodule // debounce
|
