What is the purpose of a completion interrupt at the conclusion of a DMA transfer?

Hi

I followed some hints you mentioned and still the program freezes in the mentioned while loop. Here's my EDMA config code...:

    unsigned int chIdTX0 = EDMA3_DRV_HW_CHANNEL_EVENT_1;
    unsigned int chIdTX1 = EDMA3_DRV_DMA_CHANNEL_ANY;

unsigned int tccTX0 = EDMA3_DRV_TCC_ANY;
    unsigned int tccTX1 = EDMA3_DRV_TCC_ANY;

     unsigned int tccTXLink0 = EDMA3_DRV_TCC_ANY;
    unsigned int tccTXLink1 = EDMA3_DRV_TCC_ANY;

     unsigned int chIdTXLink0 = EDMA3_DRV_LINK_CHANNEL;
    unsigned int chIdTXLink1 = EDMA3_DRV_LINK_CHANNEL;

         EDMA3_DRV_PaRAMRegs paramSetTX0 = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0};
    EDMA3_DRV_PaRAMRegs paramSetTX1 = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0};

     EDMA3_DRV_Result result = EDMA3_DRV_SOK;

     //-------------------TX1--------------------
    result = EDMA3_DRV_requestChannel(hEdma[0], &chIdTXLink1, &tccTXLink1, (EDMA3_RM_EventQueue)0, NULL, NULL);
    if (result != EDMA3_DRV_SOK) {
        return result;
    }
    result = EDMA3_DRV_requestChannel(hEdma[0], &chIdTX1, &tccTX1, (EDMA3_RM_EventQueue)0, NULL, NULL);
    if (result != EDMA3_DRV_SOK) {
        return result;
    }

    printf("CHAN: %d\n", chIdTX1); //returns 10
    printf("LINK: %d\n", chIdTXLink1); //returns 64
    printf("TCC TX1: %d\n", tccTX1); //returns 10

     paramSetTX1.srcAddr    = (unsigned int) txTmp;
    paramSetTX1.destAddr   = (unsigned int) 0x01D02000;

     paramSetTX1.srcBIdx    = 0;
    paramSetTX1.destBIdx   = 0;
    paramSetTX1.srcCIdx    = 0;
    paramSetTX1.destCIdx   = 0;

     paramSetTX1.aCnt       = 32;
    paramSetTX1.bCnt       = 5;
    paramSetTX1.cCnt       = 1;

     paramSetTX1.bCntReload = 0;

     paramSetTX1.linkAddr   = 0x4400;

     paramSetTX1.opt = (1 << 20) | (tccTX1 << 12);  //INT on completion, TCC is tccTX1

         result = EDMA3_DRV_setPaRAM(hEdma[0], chIdTXLink1, &paramSetTX1);
    if (result != EDMA3_DRV_SOK) {
        return result;
    }
    result = EDMA3_DRV_setPaRAM(hEdma[0], chIdTX1, &paramSetTX1);
    if (result != EDMA3_DRV_SOK) {
        return result;
    }

*((unsigned int *) 0x01c01060) = (1 << tccTX1); //IESR
    *((unsigned int *) 0x01c00348) |= (1 << tccTX1); //DRAE1

     //-------------------TX0-------------------
    result = EDMA3_DRV_requestChannel(hEdma[0], &chIdTXLink0, &tccTXLink0, (EDMA3_RM_EventQueue)0, NULL, NULL);
    if (result != EDMA3_DRV_SOK) {
        return result;
    }
    result = EDMA3_DRV_requestChannel(hEdma[0], &chIdTX0, &tccTX0, (EDMA3_RM_EventQueue)0, NULL, NULL);
    if (result != EDMA3_DRV_SOK) {
        return result;
    }
    printf("MAIN: %d\n", chIdTX0);
    printf("LINK: %d\n", chIdTXLink0);

     paramSetTX0.srcAddr    = (unsigned int) txAddr;
    paramSetTX0.destAddr   = (unsigned int) txTmp;

     paramSetTX0.srcBIdx    = 5;
    paramSetTX0.destBIdx   = 4;
    paramSetTX0.srcCIdx    = 1;
    paramSetTX0.destCIdx   = 0;

     paramSetTX0.aCnt       = 1;
    paramSetTX0.bCnt       = 8;
    paramSetTX0.cCnt       = 5;

     paramSetTX0.bCntReload = 0;

     paramSetTX0.linkAddr   = 0x4420;

     paramSetTX0.opt = (1 << 23) | (1 << 22) | (chIdTX1 << 12) | (1 << 2);  //chain chIdTX1 every intermediate and final transfer, AB synchronized

         result = EDMA3_DRV_setPaRAM(hEdma[0], chIdTXLink0, &paramSetTX0);
    if (result != EDMA3_DRV_SOK) {
        return result;
    }
    result = EDMA3_DRV_setPaRAM(hEdma[0], chIdTX0, &paramSetTX0);
    if (result != EDMA3_DRV_SOK) {
        return result;
    }

    result = EDMA3_DRV_enableTransfer(hEdma[0], chIdTX0, EDMA3_DRV_TRIG_MODE_EVENT);

I checked the registers and DRAE1 is 0x400, IER is 0x400 and IPR is 0x400. As I mentioned the code freezes and my ISR does not execute. If I comment the lines that set DRAE1 and IER it works just fine, but naturally I don't get any interrups either.

Also In my TCF file I have:

bios.HWI.instance("HWI_INT5").interruptSelectNumber = 8;
bios.HWI.instance("HWI_INT5").useDispatcher = 1;
bios.HWI.instance("HWI_INT5").fxn = prog.extern("pcm_isr");
bios.HWI.instance("HWI_INT5").monitor = "Nothing";

And at the beggining of main(): C64_enableIER(C64_EINT5);

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