SPRUIU1C July 2020 – February 2024 DRA821U , DRA821U-Q1
Figure 12-2222 shows the sequence to finalize a SD Command when response check is disabled. There is a possibility that some errors (Command Index/End bit/CRC/Timeout Error) occur during this sequence. If response check is enabled, error is indicated by Response Error Interrupt.
(1) If MMCSD0_TRANSFER_MODE[8] RESP_INTR_DIS bit is set to 1 (response check is enabled), go to stop (4) else wait for the Command Complete Interrupt (MMCSD0_NORMAL_INTR_STS[0] CMD_COMPLETE). If the Command Complete Interrupt has occurred, go to step (2).
(2) Write 1 to MMCSD0_NORMAL_INTR_STS[0] CMD_COMPLETE bit to clear this bit.
(3) Read the Response register (see MMCSD0_RESPONSE_0 - MMCSD0_RESPONSE_7) and get necessary information of the issued command.
(4) Judge whether the command uses the Transfer Complete Interrupt (MMCSD0_NORMAL_INTR_STS_ENA[1] XFER_COMPLETE) or not. If it uses Transfer Complete, go to step (5). If not, go to step (7).
(5) Wait for the Transfer Complete Interrupt. If the Transfer Complete Interrupt has occurred, go to step (6).
(6) Write 1 to MMCSD0_NORMAL_INTR_STS_ENA[1] XFER_COMPLETE bit to clear this bit.
(7) Check for errors in Response Data (MMCSD0_RESPONSE_0 - MMCSD0_RESPONSE_7). If there is no error, go to step (8). If there is an error, go to step (9).
(8) Return Status of "No Error".
(9) Return Status of "Response Contents Error".
Note1: While waiting for the Transfer Complete interrupt, the Host Driver shall only issue commands that do not use the busy signal.
Note2: The Host Driver shall judge the Auto CMD12 complete by monitoring Transfer Complete.
Note3: When the last block of un-protected area is read using memory multiple block read command (CMD18), OUT_OF_RANGE error may occur even if the sequence is correct. The Host Driver should ignore it. This error will appear in the response of Auto CMD12 or in the response of the next memory command.