The Seleccao lost the match after Joao Moutinho and Bruno Alves both failed from the spot, with Ronaldo - who usually takes their penalties - not having had the chance to beat Iker Casillas.
"I was going to take the fifth penalty but we missed two," Ronaldo told reporters. "It was just a question of me speaking with the coach. He said to me: 'Do you want to take the fifth one?' and I said 'yes'.
"Sometimes I take the first, the second or the third. I agreed to take the fifth.
|CARTOON OF THE DAY|
|Ronaldo STILL waiting to hit fifth penalty|
"It felt very normal playing against Real Madrid players. On the pitch we are not friends, but outside we are."
Ronaldo admitted that losing on penalties was difficult to take, but said that he believes Portugal have had a good tournament.
"I feel sad. Losing a semi-final in the penalty shoot-out is always painful, but it is a lottery: the luckier side wins," he told SIC.
"I think it was a good tournament on our part. We did very well. We are amongst the best four teams in Europe and the only reason we do not reach the final is because we were not lucky.
"We have to be proud of what we did, but we are a bit frustrated because we know we could reach the final.
"I gave my best, so I am satisfied with that I did. We deserved to be in the final, but we were not lucky."