SPRUJ28E November 2021 – September 2024 AM68 , AM68A , TDA4AL-Q1 , TDA4VE-Q1 , TDA4VL-Q1
The sequence to issue the SD Command is detailed in Figure 1-1.
(1) Check MMCSD0_PRESENTSTATE[0] INHIBIT_CMD bit. Repeat this step until MMCSD0_PRESENTSTATE[0] INHIBIT_CMD bit is 0. That is, when MMCSD0_PRESENTSTATE[0] INHIBIT_CMD bit is 1, the Host Driver shall not issue a SD Command.
(2) If the Host Driver issues a SD Command using DAT lines including busy signal, go to step (3). If without using DAT lines including busy signal, go to step (5).
(3) If the Host Driver is issuing an abort command, go to step (5). In the case of nonabort command, go to step (4).
(4) Check MMCSD0_PRESENTSTATE[1] INHIBIT_DAT bit. Repeat this step until MMCSD0_PRESENTSTATE[1] INHIBIT_DAT bit is set to 0.
(5) Set registers except the MMCSD0_COMMAND register.
(6) Set the MMCSD0_COMMAND register.
Note: Writing the upper byte [3] in the MMCSD0_COMMAND register causes the Host Controller to issue a SD command to the SD card.
(7) Perform Command Completion Sequence in accordance.