Using DMA to write to GPIO?

What's the DMA trigger? And is your code really so top-secret that you cannot show it?

Hi, Sorry about that. I actually fixed my problem, but have one more question if you have a sec. My code is shown below.

I enabled the DMA to be triggered based off the timer interrupts. However, it only seems to be triggered ONE time...unless I uncomment the code shown in the dma_1_interrupt function. By resetting up the DMA transfer, it will run again on the next timer trigger.

How can I change my DMA code to perform a DMA transfer on every timer trigger?

void DMA_Init() {
DMA_enableModule();
DMA_setControlBase(controlTable);
DMA_assignChannel(DMA_CH0_TIMERA0CCR0);
DMA_setChannelControl(UDMA_PRI_SELECT | DMA_CH0_TIMERA0CCR0,
UDMA_SIZE_8 | UDMA_SRC_INC_8 | UDMA_DST_INC_NONE | UDMA_ARB_128);
DMA_setChannelTransfer(UDMA_PRI_SELECT | DMA_CH0_TIMERA0CCR0, UDMA_MODE_AUTO, DAC_TABLE, P4POINT, 128);
DMA_enableChannel(0);
DMA_assignInterrupt(DMA_INT1, 0);
Interrupt_enableInterrupt(INT_DMA_INT1);
}

...

void dma_1_interrupt(void)
{
//DMA_setChannelTransfer(UDMA_PRI_SELECT | DMA_CH0_TIMERA0CCR0, UDMA_MODE_AUTO, DAC_TABLE, P4POINT, 128);
///DMA_enableChannel(0);
}

Additionally, this is my Timer config code.


const Timer_A_UpModeConfig upConfig =
{
TIMER_A_CLOCKSOURCE_SMCLK, // SMCLK Clock Source
TIMER_A_CLOCKSOURCE_DIVIDER_1, // SMCLK/1 = 3MHz
5000, // 5000 tick period
TIMER_A_TAIE_INTERRUPT_DISABLE, // Disable Timer interrupt
TIMER_A_CCIE_CCR0_INTERRUPT_DISABLE// ,
};

void TimerA_Init() {
Timer_A_configureUpMode(TIMER_A0_MODULE, &upConfig);
}

It would be helpful to note which MCU you're using.

I don't know anything about the ARM µDMA (and the Reference Manual isn't exactly helping), but it might be possible you need not auto mode but basic mode.

the docs for DMA_enableChannel  ( driverlib/MSP432P4xx/dma.h) say:

//! When a DMA transfer is completed, the channel is automatically disabled by
//! the DMA controller. Therefore, this function should be called prior to
//! starting up any new transfer.