Hello @ChahinezC ,
Thanks for reaching out!
I've built a specific project for the purpose of demonstrating this issue. I'll attach the .ioc and main.c files (the only ones that have been modified) and write the main code here as well for anyone interested.
If the information is helpful, I'm currently connected to a Kingston e*MMC 5.1 EMMC64G-IB29-90F02 .
I'll add the additional files in the following comments, because this only seems to allow me to attach one file at a time.
// Variable Definitions
uint8_t HAL_ret = HAL_OK;
uint8_t card_state = 0;
// eMMC optimizes card speed for repeated operations on the same memory location
// so we're randomizing the read/write location to try to reproduce error more
// frequently
uint32_t Block_Address = HAL_GetTick() % 10;
__disable_irq(); // Disabling or enabling interrupts does not seem to have an effect.
// But I'm doing this here to eliminate as many error causes as possible
for(uint8_t i=0; i<3; ++i) // Retry reading 7 times to show that after a failure, it is impossible to reconnect
{
HAL_ret = HAL_MMC_WriteBlocks(&hmmc1, buf, Block_Address*32, 32, 100);
// While I often encounter the error in my project at the first call to the emmc, I'm also adding this second call to
// cause the error to come up more often for the purposes for the test
uint32_t Block_Address = HAL_GetTick() % 10;
HAL_ret = (HAL_OK == HAL_ret) ? HAL_MMC_WriteBlocks(&hmmc1, buf, Block_Address*32, 32, 100) : HAL_ret;
// This second call may reproduce the issue a little consistently. If you want to see connection succeed, just
// comment out this second call and it will succeed most times because the card isn't overwhelmed as quickly.
if(HAL_OK == HAL_ret)
{
break;
}
else
{
__enable_irq();
//HAL_MMC_Abort(&hmmc1); // I have tried an absurd number of solutions to "reset" the card.
// None have been successful. Once the card has failed, the only method
// I've found to consistently fix it is to restart and run the "HAL_MMC_ReadBlocks()"
// in the debugger at slow speeds. Re-flashing the board often doesn't even fix the issue
// Completely DeInit-ing the mmc driver and re-initing it doesn't solve the issue
// (This attempt fails at the PowerOn() call in the Init() function)
HAL_Delay(1000); // Calling HAL_Delay with a sufficient timeout has had good results in
// the error from occurring. So has increasing the clock divider, unfortunately
// I need a fast system. (I'm already using mmc DMA in the working project)
while(hmmc1.State != HAL_MMC_STATE_READY){ // This was my initial attempt at trying to fix this error
// Unfortunately, the hmmc1 value only gives the state of the driver
// not the state of the card that's being written to
card_state = HAL_MMC_GetCardState(&hmmc1); // This is it right here. The function that should allow me to
// check the state of the physical mmc device before writing.
// I imagine if I could use this, I'd be able to query the card,
// wait for it to be ready for it to receive messages, and then
// work as intended. Unfortunately, this only ever returns "HAL_MMC_CARD_TRANSFER"
// no matter how long I wait. And even then, if waiting for the card to be ready
// was the problem, why does the FIRST call to the card fail so often?
// I've tried this on multiple boards.
}
__disable_irq();
// Try re-init-ing eMMC, then wait a little
}
}
__enable_irq();
// If everything worked perfectly, try again. This is non-deterministic
// If I use proper timeouts I'm able to avoid this error about 80% of the time
// unfortunately that's hardly acceptable for a release.
for(uint8_t i; i<20; ++i) // I ran this at the beginning at the same result, but that made the error
// harder to reproduce so I moved this down here
{
card_state = HAL_MMC_GetCardState(&hmmc1);
if(card_state != HAL_MMC_CARD_TRANSFER)
{
break;
}
}
