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`define LOG2(N) (\
N < 2 ? 0 : \
N < 4 ? 1 : \
N < 8 ? 2 : \
N < 16 ? 3 : \
N < 32 ? 4 : \
N < 64 ? 5 : \
N < 128 ? 6 : \
N < 256 ? 7 : \
N < 512 ? 8 : \
N < 1024 ? 9 : \
10)
module binary_encoder
#(
parameter SIZE = 16
)
(
input [SIZE-1:0] in,
output [`LOG2(SIZE)-1:0] out
);
genvar m,n;
generate
// Loop enough times to represent the total number of input bits as an encoded value
for (m = 0; m <= `log2(SIZE-1); m = m + 1) begin: expand_or_tree
wire [SIZE-1:0] encoding;
// Build enable mask by iterating through every input bit.
for (n = 0; n < SIZE ; n = n + 1) begin: encode_this_bit
assign encoding[n] = n[m];
end
// OR tree for this output bit with appropraite bits enabled.
assign out[m] = |(encoding & in);
end
endgenerate
endmodule // binary_encoder
|
