Notice of intent to challenge validity of prior convictions. (1) A defendant who challenges the validity of prior convictions alleged by the state as an element of felony driving while under the influence of intoxicants must give notice of the intent to challenge the validity of the prior convictions at least seven days prior to the first date set for trial on the felony charge. The validity of the prior convictions shall be determined prior to trial by the court

ORS 813.328 — under Chapter 813.