git.sur5r.net Git - cc65/blob - libsrc/pce/ticktock.s

   1         .interruptor    ticktock
   2
   3         .include        "extzp.inc"
   4
   5 ticktock:
   6         bbr5    vdc_flags,@s1   ; skip if not vertical-blank interrupt
   7
   8         ; Increment the system tick counter.
   9         inc     tickcount
  10         bne     @s1
  11         inc     tickcount+1
  12         bne     @s1
  13         inc     tickcount+2
  14         bne     @s1
  15         inc     tickcount+3
  16
  17 @s1:    rts