ciciagt - Patent cases are unique among judicial proceedings. They can be tried in any District Court, but the appeals do not go through the geographical Circuits that hear cases around the country. All patent cases come to Washington, DC to be heard on appeal.
With most court cases, when you want to appeal, you have to have "grounds." That is, you have to tell the court why you think that the trial court got it wrong - the judge was wrong about the law that was applied, you had inadequate counsel in a criminal case, etc. The appeals court is not supposed to substitute its judgment for that of the trial court. If it finds that the trial court acted in a manner that was "clearly erroneous," they send the case back for reconsideration or a new trial or some such appropriate relief.
In a patent case, the person who appeals does not have to allege any particular error. They can just say that the trial court got it wrong. They get a new hearing from the start from the Court of Appeals (called a de novo proceeding). The Court then takes its own look at all of the evidence, and can redecide the case any way it likes.
In criminal cases, you have to find someone guilty "beyond a reasonable doubt." In most civil litigation the standard is "preponderance of the evidence," meaning that something is more likely to be true than not true (just better than 50-50). In our case, IDCC will have the burden of "going forward." That means that they will have to show that they have certain patents (easy to do). Those patents will be presumed to be valid, but they will be attacked by ERICY. The ERICY burden is greater than preponderance of the evidence, but less than invalidity beyond a reasonable doubt. They will have to prove the patents invalid by "clear and convincing evidence." Given the PTO revalidation, that will be tough. If the patents are upheld, the burden then shifts back to IDCC to show that ERICY infringed (what ERICY sold used IDCC patented technology). The standard there is only preponderance of the evidence.
The parties are always free to terminate the litigation and settle at any time, even after a trial verdict or ruling on appeal. Once the Appeals Court rules, if the Supreme Court does not get the case (I don't see them getting this case - it is only about money, not the law), if they do not agree to something different, they will be stuck with the ruling of the Court of Appeals.
Sorry for the length. Hope this helps.