AM6442: GPMC Data Abort with PSRAM

Part Number: AM6442

Hello,

We have a custom board with an AM6442.A PSRAM (MRAM) is connected via 16-bit GPMC, asynchronous, non-multplexed data/address.

I based by code partly on the AM26xx PSRAM GPMC example and partly on the AM64xx NAND Flash example.

Unfortunately, when trying to read from the PSRAM I get a data abort error. For the life of me I can't figure out the problem.

I get a Synchronous External Abort:

And an ERRORNOTSUPPADD error of the GPMC:

I assume the BASEADDRESS config is wrong but this is done "automatically" by the GPMC driver:

Here are some snippets of my code:

/* GPMC attributes */
static GPMC_HwAttrs gGpmcAttrs[CONFIG_GPMC_NUM_INSTANCES] =
{
    {
        .gpmcBaseAddr         = CSL_GPMC0_CFG_BASE,
        .dataBaseAddr         = CSL_GPMC0_DATA_BASE,
        .inputClkFreq         = 133333333U,
        .intrNum              = CSLR_R5FSS0_CORE0_INTR_GPMC0_GPMC_SINTERRUPT_0,
        .intrPriority         = 4U,
        .chipSelBaseAddr      = CSL_GPMC0_DATA_BASE,
        .chipSelAddrSize      = GPMC_CS_MASK_ADDR_SIZE_16MB,
        .clkDivider           = CSL_GPMC_CONFIG1_GPMCFCLKDIVIDER_DIVBY4,
        .waitPinNum           = CSL_GPMC_CONFIG1_WAITPINSELECT_W0,
        .addrDataMux          = CSL_GPMC_CONFIG1_MUXADDDATA_NONMUX,
        .timeLatency          = CSL_GPMC_CONFIG1_TIMEPARAGRANULARITY_X1,
        .waitPinPol           = CSL_GPMC_CONFIG_WAIT0PINPOLARITY_W0ACTIVEL,
        .timingParams         =
        {
            .csOnTime               =   GPMC_PSRAM_CS_ON_TIME,
            .csRdOffTime            =   GPMC_PSRAM_CS_RD_OFF_TIME,
            .csWrOffTime            =   GPMC_PSRAM_CS_WR_OFF_TIME,
            .advOnTime              =   GPMC_PSRAM_ADV_ON_TIME,
            .advRdOffTime           =   GPMC_PSRAM_ADV_RD_OFF_TIME,
            .advWrOffTime           =   GPMC_PSRAM_ADV_WR_OFF_TIME,
            .advAadMuxOnTime        =   GPMC_PSRAM_ADV_AADMUX_ON_TIME,
            .advAadMuxRdOffTime     =   GPMC_PSRAM_ADV_AADMUX_RD_OFF_TIME,
            .advAadMuxWrOffTime     =   GPMC_PSRAM_ADV_AADMUX_WR_OFF_TIME,
            .weOnTtime              =   GPMC_PSRAM_WE_ON_TIME,
            .weOffTime              =   GPMC_PSRAM_WE_OFF_TIME,
            .oeOnTime               =   GPMC_PSRAM_OE_ON_TIME,
            .oeOffTime              =   GPMC_PSRAM_OE_OFF_TIME,
            .oeAadMuxOnTime         =   GPMC_PSRAM_OE_AADMUX_ON_TIME,
            .oeAadMuxOffTime        =   GPMC_PSRAM_OE_AADMUX_OFF_TIME,
            .pageBurstAccess        =   GPMC_PSRAM_PAGEBURST_ACCESS_TIME,
            .rdAccessTime           =   GPMC_PSRAM_RD_ACCESS_TIME,
            .wrAcessTime            =   GPMC_PSRAM_WR_ACCESS_TIME,
            .rdCycleTime            =   GPMC_PSRAM_RD_CYCLE_TIME,
            .wrCycleTime            =   GPMC_PSRAM_WR_CYCLE_TIME,
            .wrDataOnMuxBusTime     =   GPMC_PSRAM_ADMUX_DATA_VALID,
            .cycle2CycleDelay       =   GPMC_PSRAM_C2C_DELAY,
            .cycleDelaySameChipSel  =   CSL_GPMC_CONFIG6_CYCLE2CYCLESAMECSEN_NOC2CDELAY,
            .cycleDelayDiffChipSel  =   CSL_GPMC_CONFIG6_CYCLE2CYCLEDIFFCSEN_NOC2CDELAY,
            .busTurnAroundTime      =   GPMC_PSRAM_BRST_TAROUND_TIME,
        },
        .readType               =   CSL_GPMC_CONFIG1_READTYPE_RDASYNC,
        .csExDelay              =   CSL_GPMC_CONFIG2_CSEXTRADELAY_NOTDELAYED,
        .accessType             =   CSL_GPMC_CONFIG1_READMULTIPLE_RDSINGLE,
    },
};

/* GPMC Driver Parameters */
GPMC_Params gGpmcParams[CONFIG_GPMC_NUM_INSTANCES] =
{
    {
        .gpmcDmaChIndex = -1,
        .devType                =   CSL_GPMC_CONFIG1_DEVICETYPE_NORLIKE,
        .devSize                =   CSL_GPMC_CONFIG1_DEVICESIZE_SIXTEENBITS,
        .chipSel                =   GPMC_CHIP_SELECT_CS0,
        .intrEnable             =   FALSE,
        .dmaEnable              =   FALSE,
        .transferMode           =   GPMC_TRANSFER_MODE_BLOCKING,
        .transferCallBckFunc    =   NULL,
        .memDevice              =   GPMC_MEM_TYPE_PSRAM,
    },
};

int32_t mram_gpmcRead (uint32_t offset, uint8_t *buf, uint32_t len)
{
    int32_t status = SystemP_SUCCESS;
    uint32_t size =  len;

    /*if(offset + len > config->attrs->psramSize)
    {
        status = SystemP_FAILURE;
    }*/
    uint32_t baseAddress = GPMC_DATA_BASE_ADDRESS;

    volatile uint16_t *pSrc = (volatile uint16_t *)(offset+baseAddress);
    volatile uint16_t *pDst = (volatile uint16_t *)buf;
    uint32_t  remain = size & 0x1;

    if (remain != 0U)
    {
        size = size - remain + 2U;
    }

    while (size != 0U)
    {
        *pDst = *pSrc;
        pSrc++;
        pDst++;
        size -= 2U;
    }

    return status;
}

I would be very thankful for your support.

Greetings
Stefan