SPRUIU1C July 2020 – February 2024 DRA821U , DRA821U-Q1
The flow chart for detecting a SD card is shown in Figure 12-2211.
Each step is executed as follows:
To enable interrupt for card detection, write 1 to the following bits:
(1) When the Host Driver detects the card insertion or removal, clear its interrupt statuses. If Card Insertion interrupt is generated, write 1 to MMCSD0_NORMAL_INTR_STS_ENA[6] CARD_INSERTION bit. If Card Removal interrupt is generated, write 1 to MMCSD0_NORMAL_INTR_STS_ENA[7] CARD_REMOVAL bit.
(2) Check MMCSD0_PRESENTSTATE[16] CARD_INSERTED bit. In the case where MMCSD0_PRESENTSTATE[16] CARD_INSERTED bit is 1, the Host Driver can supply the power and the clock to the SD card. In the case where MMCSD0_PRESENTSTATE[16] CARD_INSERTED bit is 0, the other executing processes of the Host Driver shall be immediately closed.
If miniSD adaptor is used for standard SD slot and miniSD card is inserted or extracted from the adaptor, card detect interrupt may not be generated. When host does not receive response to any commands, miniSD card is extracted or in idle state, the host should try to re-initialize the card. In this case, all card information shall be re-loaded.