Hi all, I am beginner with VHDL-Alliance, and have some problems for to invoke custom circuit in another circuit. I have described one full adder (myFullAdder.vbe = two output's ). Now I need to describe one circuit that invoke my full adder, as one component. The question is: how can I get that alliance to recognize my circuit? How can I to define my circuit ? and later call it as one component? Example: entity circuit is port ( A, B,C: in BIT; X,Y: out BIT); end; architecture STRUCTURE of circuit is component myFullAdder <----------- This is the problem: port (A,B,C: in BIT; myFullAdder is not Scell, X,Y: out BIT); How I get that Alliance recognize it? end component; begin ...structural description... end; Thank in advance by your help!!!!! Luis A. Caceres. PD: Please help me, I not have another resource.