I am trying to port the file system including the MMC driver in sdk2 to freertos system. However , when we use usdhc2 connect to the MMC5.1 chip, we call the MMC_Init to do the initialization.
the step is 1.after the host initialization , we send CMD0 to reset the bus , seems it works. here is the function:
/* Send CMD0 to reset the bus */
if (kStatus_Success != MMC_GoIdle(card))
{
return kStatus_SDMMC_GoIdleFailed;
}
and after sending a command , it could also enter into interrupt.
but the second command, it doesnot work. after sending the command , it could not get the response and therefore could enter into interrupt handler, and then keeping waiting for the completion of transfer.
/* Hand-shaking with card to validata the voltage range Host first sending its expected
information.*/
if (kStatus_Success != MMC_SendOperationCondition(card, 0U))
{
return kStatus_SDMMC_HandShakeOperationConditionFailed;
}
could anyone give me some indications? all the code are from official NXP SDK2 package.
