SPRUIU1C July 2020 – February 2024 DRA821U , DRA821U-Q1
The flow chart for stopping the SD Clock is shown in Figure 12-2213. The Host Driver shall not stop the SD Clock when a SD transaction is occurring on the SD Bus -- namely, when either MMCSD0_PRESENTSTATE[1] INHIBIT_DAT or MMCSD0_PRESENTSTATE[0] INHIBIT_CMD bit is set to 1.
(1) Setup Internal Clock (see Figure 12-2212). Then set MMCSD0_CLOCK_CONTROL[2] SD_CLK_ENA bit to 1. Then, the Host Controller starts supplying the SD Clock.
(2) Set MMCSD0_CLOCK_CONTROL[2] SD_CLK_ENA bit to 0. Then, the Host Controller stops supplying the SD Clock. Internal Clock is still oscillating.