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Timer IRQ on the 68k

mic - Sep 20, 2009

		mic	Sep 20, 2009
		I'm trying to get a function being executed at a regular interval on the 68k by using the interrupt control on the SCSP, but it's not working properly right now. Here's basically the way I'm setting it up: I put my interrupt vector at address 0x78 in the 68k binary. // Set level 6 for the timer A interrupt SCILV0 = 0x00; SCILV1 = 0x40; SCILV2 = 0x40; // Enable timer A interrupts SCIEB = 0x40; // Set up timer A (should expire every ~23ms?) TIMA = 0; TACTL = 2; The function I specified with the interrupt vector never seems to be executed though. Are there any additional steps necessary that I've missed?

		ExCyber	Sep 20, 2009
		mic said: The function I specified with the interrupt vector never seems to be executed though. Are there any additional steps necessary that I've missed? I feel kind of silly asking this, but you never mentioned enabling interrupts on the 68K itself (with the CLI instruction). Have you done that?

		cgfm2	Sep 20, 2009
		ExCyber said: I feel kind of silly asking this, but you never mentioned enabling interrupts on the 68K itself (with the CLI instruction). Have you done that? More like "move.w #$2000, sr". If you read SCIPD are there any interrupts pending, even though they never get taken? Can you force a CPU software interrupt, or do those not work either? It's been a while but you may need to toggle the reset bit for the timer you are using in SCIRE to kick-start things.

		mic	Sep 20, 2009
		I changed the value I initialize SR with from 0x2700 to 0x2100, so now my function appears to be called because I can see some of the sound slot parameters being updated. Unfortunately the rest of the code isn't working properly, so I've still got plenty of debugging to do