prefix_ppu.asm
chalharu_nerust/roms/ppu/blargg_ppu_tests_2005.09.15b/source/prefix_ppu.asm
; Prefix included at the beginning of each test. Defines vectors
; and other things for custom devcart loader.
;
; Reset vector points to "reset".
; NMI points to "nmi" if defined, otherwise default_nmi.
; IRQ points to "irq" if defined, otherwise default_irq.

default_nmi:
	rti

default_irq:
	bit $4015
	rti

; Delays for almost A milliseconds (A * 0.999009524 msec)
; Preserved: X, Y
delay_msec:

; Delays for almost 'A / 10' milliseconds (A * 0.099453968 msec)
; Preserved: X, Y
delay_01_msec:

; Variable delay. All calls include comment stating number of clocks
; used, including the setup code in the caller.
delay_yaNN:

; Report value in low-mem variable 'result' as number of beeps and
; code printed to console, then jump to forever.
report_final_result:

; Disable IRQ and NMI then loop endlessly.
forever:


; Report error if last result was non-zero
error_if_ne:
	bne error_if_
	rts

; Report error if last result was zero
error_if_eq:
	beq error_if_
	rts

; Report error
error_if_:
	jmp report_final_result

