STM32N6 HPDMA not copying data

filipxsikora · ‎2025-01-05

Hello,

another day, another N6 "issue" :)

I want to do RAM to RAM copy by HPDMA, but the data never get copied from Src to Dest, Dest always stays unmodified. I have checked the 'DMA_RAMToRAM' example for N6 and went from there, but with no success.

DMA Init:

__HAL_RCC_HPDMA1_CLK_ENABLE();

HAL_NVIC_SetPriority(HPDMA1_Channel1_IRQn, 0, 0);
HAL_NVIC_EnableIRQ(HPDMA1_Channel1_IRQn);

handle_HPDMA1.Instance = HPDMA1_Channel1;
handle_HPDMA1.Init.Request = DMA_REQUEST_SW;
handle_HPDMA1.Init.BlkHWRequest = DMA_BREQ_SINGLE_BURST;
handle_HPDMA1.Init.Direction = DMA_MEMORY_TO_MEMORY;
handle_HPDMA1.Init.SrcInc = DMA_SINC_INCREMENTED;
handle_HPDMA1.Init.DestInc = DMA_DINC_INCREMENTED;
handle_HPDMA1.Init.SrcDataWidth = DMA_SRC_DATAWIDTH_HALFWORD;
handle_HPDMA1.Init.DestDataWidth = DMA_DEST_DATAWIDTH_HALFWORD;
handle_HPDMA1.Init.Priority = DMA_LOW_PRIORITY_HIGH_WEIGHT;
handle_HPDMA1.Init.SrcBurstLength = 2;
handle_HPDMA1.Init.DestBurstLength = 2;
handle_HPDMA1.Init.TransferAllocatedPort = DMA_SRC_ALLOCATED_PORT0 | DMA_DEST_ALLOCATED_PORT0;
handle_HPDMA1.Init.TransferEventMode = DMA_TCEM_BLOCK_TRANSFER;
handle_HPDMA1.Init.Mode = DMA_NORMAL;

if (HAL_DMA_Init(&handle_HPDMA1) != HAL_OK)
{
    Error_Handler();
}

if (HAL_DMA_ConfigChannelAttributes(&handle_HPDMA1,
            DMA_CHANNEL_PRIV | DMA_CHANNEL_SEC | DMA_CHANNEL_SRC_SEC | DMA_CHANNEL_DEST_SEC) != HAL_OK)
{
    Error_Handler();
}

And code:

__attribute((aligned(32))) uint16_t _dataSrc[128];
__attribute((aligned(32))) uint16_t _dataDst[128];

...

if (HAL_DMA_Start_IT(&handle_HPDMA1, (uint32_t)&_dataSrc[0], (uint32_t)&_dataDst[0], 256) != HAL_OK)
{
    Error_Handler();
}

if (HAL_DMA_PollForTransfer(&handle_HPDMA1, HAL_DMA_FULL_TRANSFER, 10) != HAL_OK)
{
    Error_Handler();
}

_dataSrc and _dataDst are global variables at 0x3400xxxx region (FLEXRAM).

_dataSrc contains data, checked.

When I use memcpy, that works. When I use GPDMA1 with exactly the same parameters, that also works. But HPDMA doesn't. No error I can see happened, not stuck in Error_Handler, no HardFault.. The code just executes normally and continues after that, so the transfer completed correctly. Yet the _dataDst stays unmodified.

L1 D-cache was off for these tests.

What am I missing?

Thank you.

ANJS · ‎2025-01-10

Hello!
you need to configure the Resource isolation slave unit for address space protection in order to let the HPDMA1 master to have access to SRAM2 or SRAM1

/*RISAF2 => SRAM1_AXI */
/*RISAF3 => SRAM2_AXI */

RISAF3->REG[0].CFGR = 0x00000000;

RISAF3->REG[1].CFGR = 0x00000000;

RISAF3->REG[0].CIDCFGR = 0x000F000F; /* RW for everyone */

RISAF3->REG[0].ENDR = 0xFFFFFFFF; /* all-encompassing */

RISAF3->REG[0].CFGR = 0x00000101; /* enabled, secure, unprivileged for everyone */

RISAF3->REG[1].CIDCFGR = 0x00FF00FF; /* RW for everyone */

RISAF3->REG[1].ENDR = 0xFFFFFFFF; /* all-encompassing */

RISAF3->REG[1].CFGR = 0x00000001; /* enabled, non-secure, unprivileged*/

For further information see the chapter 7. Resource isolation slave unit for address space
protection of the reference manual RM0486.
Best regards

View solution in original post

AScha.3 · ‎2025-01-05

Hi,

> What am I missing?

Look at the registers of HPDMA before and after the "transfer" (in debug).

Should show, what HPDMA doing - or not.

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filipxsikora · ‎2025-01-06

Hello,

Checked the registers, I didn't see any error flags being set, or anything weird, just Transfer Complete flag.

I've also registered the callbacks

HAL_DMA_RegisterCallback(&handle_HPDMA1, HAL_DMA_XFER_CPLT_CB_ID, TransferCompleteHPDMA);
HAL_DMA_RegisterCallback(&handle_HPDMA1, HAL_DMA_XFER_ERROR_CB_ID, TransferErrorHPDMA);

And I've got the TransferComplete CB every time, never the TransferError.

But result is still the same, data at the destination not being modified.

ANJS · ‎2025-01-10