.global _pause
_pause:
	;; This routine does not actually enable interrupts.
	;; The CPU goes to power-down mode PD1. Wake-up from PD1 is
	;; triggered by a non-enabled interrupt, normally INT7.
	;; Execution continues without need for an interrupt service packet.
	;; See Instruction Set Reference page XXX.
	B	Next
	MVC	CSR,B5		; copy control status register
	ADDK	0x4400,B5	; select PD1 wake by non-enabled interrupt
	MVC	B5,CSR		; enter PD1
	NOP
	NOP
Next:	NOP
	NOP	6

	B	B3		; return to caller
	MVC	IFR,B5
	MV	B5,A4		; return value is IFR register
	MVK	0x80,B3
	MVC	B3,ICR		; clear INT7
	NOP