I'm sorry if this is something obvious, but I couldn't find any information about this.
I was failing Blargg's ppu_vbl_nmi test suite #8: nmi_off_timing.
(here nmi is disabled right before vblank and the test checks whether NMI triggers)
I noticed that I could pass this by not polling for interrupts during the last NOP cycle.
But fixing this instead breaks another test from cpu_interrupts_v2, #5: branch_delays_irq
(this one checks the conditions under which branches polls for interrupts)
So, obviously both can't be right, but which one is? Does int. polling occur during a NOP or not?
Thanks!
J
I was failing Blargg's ppu_vbl_nmi test suite #8: nmi_off_timing.
(here nmi is disabled right before vblank and the test checks whether NMI triggers)
I noticed that I could pass this by not polling for interrupts during the last NOP cycle.
But fixing this instead breaks another test from cpu_interrupts_v2, #5: branch_delays_irq
(this one checks the conditions under which branches polls for interrupts)
So, obviously both can't be right, but which one is? Does int. polling occur during a NOP or not?
Thanks!
J