1
0
mirror of https://github.com/cc65/cc65.git synced 2024-11-03 10:07:02 +00:00
cc65/libsrc/gamate/irq.s

53 lines
961 B
ArmAsm
Raw Normal View History

2015-11-29 00:14:59 +00:00
;
; IRQ handling (Gamate version)
;
.export initirq, doneirq, IRQStub
.import __INTERRUPTOR_COUNT__, callirq_y
.include "gamate.inc"
.include "extzp.inc"
; ------------------------------------------------------------------------
.segment "ONCE"
2015-11-29 00:14:59 +00:00
; a constructor
;
initirq:
rts
; ------------------------------------------------------------------------
.code
; a destructor
;
doneirq:
rts
; ------------------------------------------------------------------------
; 256*32 interrupts in about 1minute 60s = 136hz
; -> guess 16384 clock cycles = 135,28hz (might be audio signal 1/512?)
IRQStub:
2015-11-29 19:04:10 +00:00
; A and Y are saved by the BIOS
;pha
;tya
;pha
2015-11-29 00:14:59 +00:00
ldy #<(__INTERRUPTOR_COUNT__ * 2)
beq @L1
txa
pha
jsr callirq_y
pla
tax
2015-11-29 19:04:10 +00:00
@L1: ;pla
;tay
;pla
2015-11-29 00:14:59 +00:00
rts