California Code, Penal Code - PEN § 1203.085

(a) Any person convicted of an offense punishable by imprisonment in the state prison but without an alternate sentence to a county jail shall not be granted probation or have the execution or imposition of sentence suspended, if the offense was committed while the person was on parole from state prison pursuant to Section 3000, following a term of imprisonment imposed for a violent felony, as defined in subdivision (c) of Section 667.5, or a serious felony, as defined in subdivision (c) of Section 1192.7.

(b) Any person convicted of a violent felony, as defined in subdivision (c) of Section 667.5, or a serious felony, as defined in subdivision (c) of Section 1192.7, shall not be granted probation or have the execution or imposition of sentence suspended, if the offense was committed while the person was on parole from state prison pursuant to Section 3000.

(c) The existence of any fact that would make a person ineligible for probation under subdivision (a) or (b) shall be alleged in the information or indictment, and either admitted by the defendant in open court, or found to be true by the jury trying the issue of guilt or by the court where guilt is established by plea of guilty or nolo contendere or by trial by the court sitting without a jury.