The 27-year-old has been in excellent form in Poland and Ukraine in his side's last two matches, scoring three goals to send the Seleccao to the last-four stage.
He will face some of his Real Madrid team-mates in the quarterfinals and also several familiar La Liga opponents, but Ronaldo insisted that it will not be different to any other high-profile encounter for club and country.
"There is not any special pressure just because I am facing Spain," he tells Uefa.com. "I have been playing at the highest level for 10 years, both at club and international level. Yes, I feel responsibility, but not pressure. I am used to these matches."
Spain are viewed as favourites for the match, but the 27-year-old thinks that the Seleccao will be able to repeat their performance from Euro 2004, when they reached the tournament decider.
"It is nice to have the chance to be in the final eight years later," Ronaldo added. "It will be very hard, but we are just one step away from doing it.
"Spain are a great side and it will be a very interesting Iberian contest, one which I hope we can win. But it will be a tough battle."