module pad_io ( PAD, A, Y, EN );
inout PAD;
input A;
input EN;
output Y;

assign Y = PAD;
assign PAD = ~EN ? A : 1'bz;
endmodule

module pad_io2 ( PAD, A, Y, E );
inout PAD;
input A;
input E;
output Y;

assign Y = PAD;
assign PAD = E ? A : 1'bz;
endmodule

module pad_ot ( PAD, A, EN );
output PAD;
input A;
input EN;

assign PAD = ~EN ? A : 1'bz;
endmodule

module pad_i ( PAD, Y );
input PAD;
output Y;

assign Y = PAD;
endmodule