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Question

SD card is always in 'TRANSFER' state.

Forum|Forum|5 years ago
November 12, 2020
6 replies
2770 views

Hi

I'm using STM32F103VGT6 and now days i have a problem in working with SD cards.

I can't use FatFs library.

"HAL_SD_GetCardState" function, always return 'TRANSFER' state.

I try multiple SD cards, clock divider and any many configs.

please help.

thanks

STM32F1 series

This topic has been closed for replies.

TDK

The TRANSFER state is where the card is most of the time. Do you think it should be in a different state?

https://user-images.githubusercontent.com/77482/29501948-45c1c196-85e1-11e7-9bfc-d4817115d5bb.png

"If you feel a post has answered your question, please click ""Accept as Solution""."

ENo.1Author

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thanks @TDK

This function (HAL_SD_GetCardState) has multiple output.

For example:

-HAL_SD_CARD_READY

Card state is ready

-HAL_SD_CARD_IDENTIFICATION

Card is in identification state

-HAL_SD_CARD_STANDBY

Card is in standby state

-HAL_SD_CARD_TRANSFER

Card is in transfer state

-HAL_SD_CARD_SENDING

Card is sending an operation

-HAL_SD_CARD_RECEIVING

Card is receiving operation information

'HAL_SD_CARD_READY' state, means SD card is ready for do an operation.

It seems that in most of the time, SD card must in READY state, not TRANSFER state.

in TRANSFER state, i can't read or write from/to SD card. it means SD card is doing an operation and its busy.

TDK

> in TRANSFER state, i can't read or write from/to SD card. it means SD card is doing an operation and its busy.

That's simply not true. Most commands, including read/write commands, are initiated when the card is in the transfer state. See the graph that I linked. If you have a copy of the SD standard, there are more details in there. I linked the figure for eMMC, but SD is similar.

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