Oregon Revised Statutes Procedure in Criminal Matters Generally § 135.037

(1) At any time after the filing of the accusatory instrument in circuit court and before the commencement of trial thereon, the court upon motion of any party shall, and upon its own motion may, order an omnibus hearing.

(2) The purpose of an omnibus hearing shall be to rule on all pretrial motions and requests, including but not limited to the following issues:

(3) The court, at the time of the omnibus hearing, may also consider any matters that will facilitate trial by avoiding unnecessary proof or by simplifying the issues to be tried, or that are otherwise appropriate under the circumstances to facilitate disposition of the proceeding.

(4) At the conclusion of the hearing and prior to trial the court shall prepare and file an order setting forth all rulings of the court on issues raised under subsection (2) of this section. The court shall further prepare and file a memorandum of other matters agreed upon at the hearing. Except in a prosecution of the defendant for perjury or false swearing, or impeachment of the defendant, admissions made by the defendant or the attorney of the defendant at the hearing may not be used against the defendant unless the admissions are reduced to writing and signed by the defendant and the attorney.

(5) This section may not be applied in any proceeding or at any stage of any proceeding where the defendant is not represented by counsel.