SPRUIM2H May 2020 – October 2023 AM2431 , AM2432 , AM2434 , AM6411 , AM6412 , AM6421 , AM6422 , AM6441 , AM6442
This procedure is invoked by the Card Insertion interrupt. Figure 12-1781 and Table 12-3433 show a card interface detection sequence.
Step | Description |
---|---|
1 | Set Internal Clock Enable to 1 in the MMCSD0_CLOCK_CONTROL register. |
2 | Wait until Internal Clock Stable is set to 1 in the MMCSD0_CLOCK_CONTROL register. |
3 | If Host Supports UHS-II, go to step (4) else go to step (12). |
4 | Try to initialize a card to UHS-II mode. Set UHS-II Interface Enable to 1 in the MMCSD0_HOST_CONTROL2 register, set SD Bus Power for VDD1 and SD Bus Power for VDD2 to 1 in the MMCSD0_POWER_CONTROL register, and set UHS Mode Select to 111b in the MMCSD0_HOST_CONTROL2 register. |
5 | Wait power ramp up time. It is dependent on a Host System. |
6 | Set SD Clock Enable to 1 in the MMCSD0_CLOCK_CONTROL register. |
7 | Wait 200 µs to check a card supports UHS-II mode. |
8 | Check STB.L Detection in the MMCSD0_PRESENTSTATE register. If UHS-II IF is detected, go to step (9). If UHS-II IF is not detected, go to step (11). |
9 | Wait until Lane Synchronization in the MMCSD0_PRESENTSTATE register is set to 1 (PHY Initialization is completed). |
10 | Perform UHS-II initialization. |
11 | Perform card power cycle. |
12 | Try to initialize a card to SD 4-bit mode. Set UHS-II Interface Enable to 0 in the MMCSD0_HOST_CONTROL2 register, set SD Bus Power for VDD1 to 1 in the MMCSD0_POWER_CONTROL register, and set UHS Mode Select to 000b in the MMCSD0_HOST_CONTROL2 register. |
13 | Wait power ramp up time. It is dependent on a Host System. |
14 | Set SD Clock Enable to 1 in the MMCSD0_CLOCK_CONTROL register. |
15 | Perform SD 4-bit mode initialization. Refer to Section 12.3.5.5.1.6, Card Initialization and Identification (for SD I/F). |