Author Topic: How to stop interrupts being disabled after exiting app? (Read 3578 times)

fb39ca4 · « **on:** January 08, 2014, 10:14:43 pm »

I was trying to figure out why the calculator kept on freezing after Bad Apple finished, and it turns out iff1 and iff2 were disabled. I enable interrupts and set the interrupt mode to 1 immediately before doing bjump(_JForceCmdNoChar). iff1 and iff2 are enabled when that happens, but sometime after the bjump, the interrupts get disabled. What is going on here?

Iambian · « **Reply #1 on:** January 08, 2014, 10:17:06 pm »

You probably need to set interrupt mode to 1, THEN enable interrupts again, not the other way around.

You also need to disable the crystal timers. The OS interrupts requires one of them, I think. Also, did you reset the normal interrupts?

NOTE: This post was edited too many times shortly after the initial post. I really need to collect my thoughts better.

fb39ca4 · « **Reply #2 on:** January 08, 2014, 10:22:13 pm »

I am already doing im 1 first and then ei. The crystal timers are disabled by writing 0 to ports $30-$38, and the regular interrupts are restored by writing $0B to port $03.

Iambian · « **Reply #3 on:** January 08, 2014, 10:24:27 pm »

Posting the relevant parts of the code may help. Also, posting how you set up the interrupt may also be helpful.

thepenguin77 · « **Reply #4 on:** January 08, 2014, 10:25:27 pm »

This code will fix the interrupts. If it crashes after this, interrupts are not the issue. Also, you don't need to enable interrupts when you quit, the OS takes care of that for you.

Code: [Select]

	di
	im	1
	ld	a, $0B
	out	(03), a
	xor	a
	out	($31), a
	out	($34), a
	out	($37), a

fb39ca4 · « **Reply #5 on:** January 08, 2014, 10:31:21 pm »

Setting up the interrupts:

Code: [Select]

	;set up interrupt vector table from $9900 to $9A00 to always go to $9A9A
	ld hl, $9900
	ld b, 0
	ld d, $9A
IvtLoop:
  ld (hl), d
  inc hl
  djnz IvtLoop
  ld (hl), d

Code: [Select]

;disable all other interrupts
  ld a, %01000
  out ($03), a

Code: [Select]

ld a, $99
  ld i, a
  im 2
  ei

Cleanup:

Code: [Select]

di
  ;turn off timers
  ld a, 0
  out ($30), a
  out ($31), a
  out ($32), a
  out ($33), a
  out ($34), a
  out ($35), a
  out ($36), a
  out ($37), a
  out ($38), a
  ;restore regular interrupts
  ld a, 0
  out ($03), a
  ld a, $0B
  out ($03), a
  ;set LCD to row auto increment
  ld a, $05
  call LCD_BUSY_QUICK
  out ($10), a
  ;set CPU to 6MHz
  ld a, 0
  out ($20), a
  ;statVars was used to store code, so it needs to be invalidated
	b_call _DelRes
  ;enable auto power down
	set apdAble,(IY+apdFlags)
	im 1
	ei
	bjump(_JForceCmdNoChar)

EDIT: Tried thepenguin77's code, and it looks like interrupts are not the problem.

Xeda112358 · « **Reply #6 on:** January 10, 2014, 09:46:42 am »

Are you doing any RAM page swapping or stack pointer manipulation?

Author Topic: How to stop interrupts being disabled after exiting app? (Read 3578 times)

fb39ca4

How to stop interrupts being disabled after exiting app?

Iambian

Re: How to stop interrupts being disabled after exiting app?

fb39ca4

Re: How to stop interrupts being disabled after exiting app?

Iambian

Re: How to stop interrupts being disabled after exiting app?

thepenguin77

Re: How to stop interrupts being disabled after exiting app?

fb39ca4

Re: How to stop interrupts being disabled after exiting app?

Xeda112358

Re: How to stop interrupts being disabled after exiting app?