At 12:41 PM 8/20/99 +0200, you wrote:
>If executed between a DI and an EI it indeed cancels the interrupt (if not
>between DI and EI it's useless because if the interrupts are enabled the
>interrupt-routine itself will 1. read the register itself and therefor erase
>it, or 2. not read the register and end up in an infinite loop of
>interrupts.
When Frits talked about "cancelling", he didn't mean clearing the interrupt
flag by reading the status register. The question is what happens when the
Z80 is in a DI state, a VDP interrupt occurs and then the interrupts are
disabled at VDP level (using IE0 or IE1, depending on the type of
interrupt) before the Z80 reaches EI state.
Bye,
Maarten
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