eDMA bus error ext. sdram

[martinmadron]

Hello,

i have a bus error when i try to write/read data with edma from/to external SDRAM. Every time i get source or destination bus error. For data transfers in internal RAM or flash to internal RAM it works fine.

I can also write and read data manualy to/from SDRAM with no problem.

Can it be somehow related to PACR and MPR registers?

platform :TWR-K65, MQX, KSDK 1.3

Buffers (buffram is external memory section)

uint8_t destinationBuff[1000];
 __attribute__((section(".buffram"))) uint8_t sourceBuff[1000] = {1,1,2,3,4,5,6,7,8,9};

Init function

void trasferInitEdma( void)
{
    edma_status_t initStatus;
    edma_chn_state_type_t channelT;
    //  OSA_InstallIntHandler(UART0_RX_TX_IRQn, uartCom1_IRQHandler);
    OSA_InstallIntHandler(DMA0_DMA16_IRQn,  dmaController1_Chn0IRQHandler);
    OSA_InstallIntHandler(DMA_Error_IRQn,  dmaController1_Chn0ErrorIRQHandler);
    // initialiye edma drive
    //--------------------------
    initStatus = EDMA_DRV_Init(&dmaController1_State,&dmaController1_InitConfig0);
    if ( initStatus != kStatus_EDMA_Success )
    {
          __BKPT(3);
    }
    // request edma channel
    channelT = EDMA_DRV_RequestChannel(kEDMAAnyChannel, kDmaRequestMux0AlwaysOn60, &dmaController1_ChnState0);
    initStatus = EDMA_DRV_InstallCallback(&dmaController1_ChnState0, dmaController1_Callback0, NULL);
    if ( initStatus != kStatus_EDMA_Success )
          {
              __BKPT(6);
          }
}

transfer fnc

void tranferDataEdma(uint8_t * source, uint8_t * destination, size_t size )
{
    myTransferStatus = transferInProgress;
    edma_software_tcd_t transferDescriptor __attribute__((aligned (32)));
    edma_transfer_config_t edmaTransferConfig;
    edmaTransferConfig.srcAddr            = (uint32_t)source;
    edmaTransferConfig.destAddr           = (uint32_t)destination;
    edmaTransferConfig.srcTransferSize    = kEDMATransferSize_1Bytes;
    edmaTransferConfig.destTransferSize   = kEDMATransferSize_1Bytes;
    edmaTransferConfig.srcOffset          = 1U;
    edmaTransferConfig.destOffset         = 1U;
    edmaTransferConfig.srcLastAddrAdjust  = 0U;
    edmaTransferConfig.destLastAddrAdjust = 0U;
    edmaTransferConfig.srcModulo          = kEDMAModuloDisable;
    edmaTransferConfig.destModulo         = kEDMAModuloDisable;
    edmaTransferConfig.minorLoopCount     = 1U;
    edmaTransferConfig.majorLoopCount     = size;
    memset(&transferDescriptor, 0, sizeof(edma_software_tcd_t));
    EDMA_DRV_PrepareDescriptorTransfer(&dmaController1_ChnState0,
                                       &transferDescriptor,
                                       &edmaTransferConfig,
                                       true,
                                       true);
    /* Copies the software TCD configuration to the hardware TCD */
    EDMA_DRV_PushDescriptorToReg(&dmaController1_ChnState0, &transferDescriptor);
    /* Start DMA channel */
    EDMA_DRV_StartChannel(&dmaController1_ChnState0);

EDMA_DRV_PushDescriptorToReg(&dmaController1_ChnState0, &transferDescriptor);

/* Start DMA channel */

    EDMA_DRV_StartChannel(&dmaController1_ChnState0);

}

[Carlos_Musich]

Hello Martin,

Are you using Flexbus to communicate with external RAM?

Carlos

[martinmadron]

I am using SDRAM controler. I have tried many different dma transfers with success, but whenever i "touch" sdram with dma, i get bus error.

[Carlos_Musich · Accepted solution]

Hi Martin,

what address are you using for SDRAM? Please note that 0x08000000 is alieased and only accesible by the core.

On the other hand there are 0x70000000 and 0x80000000 which are Write-back and write-through memory areas. In these cases if you have cache disabled there should be no problem, but if is you should flush cache in case you  use write-back space.

I hope this information helps.

Best regards,
Carlos

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[martinmadron]

Hello Carlos,

you are right. It is exactly my problem. Thank you for your response. I should read manual more carefully :smileyhappy:.

Have a nice day.