ID:13035 Inserted always-enabled tri-state buffer between "<name>" and its non-tri-state driver.

CAUSE: The Quartus Prime software expected the specified node to be driven by tri-state drivers, but the node is driven by non-tri-state logic. As a result, the Quartus Prime software inserted an always-enabled tri-state buffer between the node and the non-tri-state driver to make the netlist valid. For example, the following Verilog design gives this warning:

		module test1 (input in1, in2, in3, oe1, oe2, output out1, inout bi1, inout bi2); 
		reg tri_wire; 
		wire tmp_bidir; 
		always @ (*) 
		begin 
			if (oe1) 
				tri_wire <= in1; 
			else if (oe2) 
				tri_wire <= in2; 
			else 
				tri_wire <= 1'bZ; 
		end 
		assign out1 = tri_wire; 
		assign bi1 = tri_wire; 
		nand (tmp_bidir, bi1, in3); 
		assign  bi2 = tmp_bidir; 
   		endmodule  
	
            

In the design test1, the bidirectional pin bi2 is driven by non-tri-state logic. As a result, this warning will be given for that pin. The following design also gives this warning for the output pin out.

		module test2 (input in1, in2, in3, oe1, oe2, output out); 
				reg tri_wire; 
		wire tmp_bidir; 
		assign out = oe1 ? in1 : 1'bz; 
		assign out = oe2 ? in2 : 1'bz; 
		assign out = in3; 
			endmodule