LPC4337 SDIO Read_Direct for instance card size

valeremar — Mon, 20 Feb 2017 21:24:31 GMT

Dear All,

I am using SDIO to store data on a SD card and I would like to get the SD card size/capacity [in GB] (which corresponds to CMD9 with SD protocol and SPI). In the example ''periph_SDIO'', there is:

SDIO_Read_Direct(LPC_SDMMC, 1, 0x1C, &val) and SDIO_Read_Direct(LPC_SDMMC, 1, 0x1D, &val)

Where do the 0x1C or 0x1D come from ?

I look into the file "simplified_SDIO_card_spec.pdf" but cannot make sense of it to answer the question above. I understand that the information should be in the FBR -> CIS register (right?).

Looking further in the "periph_SDIO" example, there is SDIO_Read_Direct(LPC_SDMMC, 1, 0x04, &val) (clear the interrupt). Again, I am not able to understand or to calculate the 0x04 address.

Could you explain or point to a good document in order to understand these addresses?

Thank you very much.

Re: LPC4337 SDIO Read_Direct for instance card size

kerryzhou — Wed, 22 Feb 2017 10:37:19 GMT

Hi Valeremar,

I checked the SDIO_Read_Direct function, it is using the CMD52 to access the according register.

From the CMD52 command description, we can get the CMD52 can access a signal register within the total 128K of register space in any I/O function, including the common I/O area (CIA).

As you know, CIS is included in the CIA register.

So, I think the 0X1D, 0X1C, 0X04 is not the address, it should be the SDIO register.

More details, you also can refer to the SDIO card spec:

http://ugweb.cs.ualberta.ca/~c274/resources/hardware/SDcards/SD_SDIO_specsv1.pdf

https://www.sdcard.org/developers/overview/sdio/sdio_spec/Simplified_SDIO_Card_Spec.pdf

Associated with these code to find the according SDIO register which is controlled by the CMD52:

int SDIO_Write_Direct(LPC_SDMMC_T *pSDMMC, uint32_t func, uint32_t addr, uint32_t data)
{
int ret;

ret = SDIO_Send_Command(pSDMMC, CMD52, (func << 28) | (addr << 9) | (data & 0xFF) | (1UL << 31));
if (ret) return ret;

   /* Check response for errors */
   if(sdioif->response[0] & 0xcb00){
                       /* COM_CRC_ERROR */
                       /* ILLEGAL_CRC_ERROR */
                       /* ERROR */
                       /* RFU FUNCTION_NUMBER */
                       /* OUT_OF_RANGE */
       /* Response flag error */
       return SDIO_ERR_READWRITE;
   }
   return data != (sdioif->response[0] & 0xFF);
}

uint32_t SDIO_Send_Command(LPC_SDMMC_T *pSDMMC, uint32_t cmd, uint32_t arg)
{
   uint32_t ret, ival;
   uint32_t imsk = pSDMMC->INTMASK;
   ret = sdioif->wait_evt(pSDMMC, SDIO_START_COMMAND, (void *)(cmd & 0x3F));
   ival = SDIO_CMD_INT_MSK & ~ret;

   /* Set data interrupts for data commands */
   if (cmd & SDIO_CMD_DATA) {
       ival |= SDIO_DATA_INT_MSK;
       imsk |= SDIO_DATA_INT_MSK;
   }

   Chip_SDIF_SetIntMask(pSDMMC, ival);
   Chip_SDIF_SendCmd(pSDMMC, cmd, arg);
   ret = sdioif->wait_evt(pSDMMC, SDIO_WAIT_COMMAND, 0);
   if (!ret && (cmd & SDIO_CMD_RESP_R1)) {
       Chip_SDIF_GetResponse(pSDMMC, &sdioif->response[0]);
   }

Chip_SDIF_SetIntMask(pSDMMC, imsk);
return ret;
}

Wish it helps you!

Have a great day,
Kerry

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LPC4337 SDIO Read_Direct for instance card size

Re: LPC4337 SDIO Read_Direct for instance card size