What is the duty of a judge to suspend trial proceedings and conduct a competency hearing?

"Both federal due process and state law require a trial judge to suspend trial proceedings and conduct a competency hearing whenever the court is presented with substantial evidence of incompetence, that is, evidence that raises a reasonable or bona fide doubt concerning the defendant's competence to stand trial. [Citations.] The court's duty to conduct a competency hearing may arise at any time prior to judgment." ( People v. Rogers , supra , 39 Cal.4th at p. 847, 48 Cal.Rptr.3d 1, 141 P.3d 135 ; see also 1368.)