What is the Miranda requirement for a suspect to waive his right to silence during questioning?

The requirements of Miranda are well-established. To assure protection of the Fifth Amendment privilege against self-incrimination, "a suspect may not be subjected to an interrogation in official 'custody' unless he has previously been advised of, and has knowingly and intelligently waived, his rights to silence, to the presence of an attorney, and to appointed counsel if he is indigent. Even if the suspect initially waives these rights and [17 Cal.App.4th 1481] respondsto interrogation, he may reinvoke them at any time. If he does so 'in any manner and at any stage of the process,' his request to terminate the questioning or obtain counsel must be 'scrupulously honored.' [Citation.] Statements obtained in violation of Miranda are not admissible to establish his guilt." (People v. Boyer, supra, 48 Cal.3d at p. 271, 256 Cal.Rptr. 96, 768 P.2d 610.)