#define DMA_CHANNEL_ENABLE      1
    #define DMA_TRANSFER_TYPE_M2P   (1UL << 11)   
    #define DMA_CHANNEL_TCIE        (1UL << 31)
    #define DMA_CHANNEL_SRC_INC     (1UL << 26)
    #define DMA_MASK_IE             (1UL << 14)
    #define DMA_MASK_ITC            (1UL << 15)

    /* Enable The transmit FIFO for the DMA */
    LPC_SSP1->DMACR|=2;
    
    /* Power up the GPDMA. */
    LPC_SC->PCONP |= (1UL << 29);
    LPC_GPDMA->DMACConfig = 1;
    LPC_GPDMA->DMACIntTCClear = 0x1;
    NVIC_EnableIRQ(DMA_IRQn);
       
    /* Prep Channel0 to send 1024 byte to the SSP. */
    LPC_GPDMACH0->DMACCSrcAddr  = (uint32_t)buffer;
    LPC_GPDMACH0->DMACCDestAddr = (uint32_t)&LPC_SSP1->DR;
    LPC_GPDMACH0->DMACCLLI      = 0;
    LPC_GPDMACH0->DMACCControl  = DMA_CHANNEL_TCIE | DMA_CHANNEL_SRC_INC | 1024;

    /* Fire GPDMA Channel0 */
    LPC_GPDMACH0->DMACCConfig = DMA_CHANNEL_ENABLE | 
                                DMA_TRANSFER_TYPE_M2P |
                                DMA_MASK_IE |
                                DMA_MASK_ITC;

extern "C" void DMA_IRQHandler(void) __irq {
    if (LPC_GPDMA->DMACIntStat & 1) {
        if (LPC_GPDMA->DMACIntTCStat & 1) {
            myled3 = 1;    
            LPC_GPDMA->DMACIntTCClear = 1;
        }
        if (LPC_GPDMA->DMACIntErrStat & 1) {
            myled4 = 1;
            LPC_GPDMA->DMACIntErrClr = 1;
        }
    }
}

Hello to all, I'm trying to configure the DMA to send data to the SSP1 (mbed SPI pins: 5, 6, 7).\\ I modified the code from this topic[1] in this way: <<code>> #define DMA_CHANNEL_ENABLE 1 #define DMA_TRANSFER_TYPE_M2P (1UL << 11) #define DMA_CHANNEL_TCIE (1UL << 31) #define DMA_CHANNEL_SRC_INC (1UL << 26) #define DMA_MASK_IE (1UL << 14) #define DMA_MASK_ITC (1UL << 15) /* Enable The transmit FIFO for the DMA */ LPC_SSP1->DMACR|=2; /* Power up the GPDMA. */ LPC_SC->PCONP |= (1UL << 29); LPC_GPDMA->DMACConfig = 1; LPC_GPDMA->DMACIntTCClear = 0x1; NVIC_EnableIRQ(DMA_IRQn); /* Prep Channel0 to send 1024 byte to the SSP. */ LPC_GPDMACH0->DMACCSrcAddr = (uint32_t)buffer; LPC_GPDMACH0->DMACCDestAddr = (uint32_t)&LPC_SSP1->DR; LPC_GPDMACH0->DMACCLLI = 0; LPC_GPDMACH0->DMACCControl = DMA_CHANNEL_TCIE | DMA_CHANNEL_SRC_INC | 1024; /* Fire GPDMA Channel0 */ LPC_GPDMACH0->DMACCConfig = DMA_CHANNEL_ENABLE | DMA_TRANSFER_TYPE_M2P | DMA_MASK_IE | DMA_MASK_ITC; extern "C" void DMA_IRQHandler(void) __irq { if (LPC_GPDMA->DMACIntStat & 1) { if (LPC_GPDMA->DMACIntTCStat & 1) { myled3 = 1; LPC_GPDMA->DMACIntTCClear = 1; } if (LPC_GPDMA->DMACIntErrStat & 1) { myled4 = 1; LPC_GPDMA->DMACIntErrClr = 1; } } } <</code>> But the DMA transfer never start!\\ Where am I doing wrong? [1] http://mbed.org/forum/mbed/topic/1138/?page=1#comment-5543

Take a look at [[/cookbook/MODDMA|MODDMA]] library I released.

Hello Andy, I try your lib too, but with the same result! Do I need to make a write to the SPI to start the DMA transfer? It seems as if missing the start! TIA <<quote AjK>> Take a look at [[/cookbook/MODDMA|MODDMA]] library I released. <</quote>>

    /* Enable SSP0 for DMA. */
    LPC_SSP0->DMACR = 0x3;

// or...

    /* Enable SSP1 for DMA. */
    LPC_SSP1->DMACR = 0x3;

No, write not required. Enabling the DMA channel should be enough to start teh transfer. Did you remember to enable the SSP for DMA?... <<code>> /* Enable SSP0 for DMA. */ LPC_SSP0->DMACR = 0x3; // or... /* Enable SSP1 for DMA. */ LPC_SSP1->DMACR = 0x3; <</code>>

You may find this useful as a reference... [[/users/AjK/programs/SOWB/lg489e/docs/flash__read_8c_source.html]]

    /* Enable The transmit FIFO for the DMA */
    LPC_SSP1->DMACR|=2;

Yes, I use <<code>> /* Enable The transmit FIFO for the DMA */ LPC_SSP1->DMACR|=2; <</code>> and I try the value 3 as on your example. But without success.\\ Before to configure the DMA I configure the SPI pins, format and speed.\\ The SPI at pins 5, 6 and 7 is the SSP1 so I'm sure I'm using the correct one... <<quote AjK>> No, write not required. Enabling the DMA channel should be enough to start teh transfer. Did you remember to enable the SSP for DMA?... <</quote>>

If you see the reference above I use the DMA to transfer pages from a flash device at 25MHz without any problems. Have a look through that, otherwise can you publish your program and place a link here so we can see it in whole?

Andy,\\ I saw that I do not have \\ LPC_GPDMA->DMACSoftSReq = 0xC;\\ in my code. Let me try this code...\\ Thank you for the fast replay! <<quote AjK>> If you see the reference above I use the DMA to transfer pages from a flash device at 25MHz without any problems. Have a look through that, otherwise can you publish your program and place a link here so we can see it in whole? <</quote>>