;
; macros.inc -- various useful general-purpose macros
;
; Bret Victor, Sept 12, 1998

; _entercritcal and _leavecritical are used for disabling
; interrupts within a section.  Why not just use sei and cli?
; Well, if interrupts are already disabled (say, you call the
; function within an interrupt proc), the cli will enable them,
; and you really don't want that to happen.  These macros
; provide a safe way of disabling interrupts.  I just wish there
; were psp and plp (push P, pull P) instructions like in 65C816...

	mac	_entercritical
	tpa		; put p in a
	psha		; save it
	sei		; set interrupt disable
	endm

	mac	_leavecritical
	pula		; get p
	tap		; put it back
	endm