SPRUIE9D May 2017 – May 2024 DRA74P , DRA75P , DRA76P , DRA77P
Figure 27-2 shows the eMMC/SD/SDIOi host controller (where i = 1 to 4) connected to an eMMC, SD, or SDIO card and its related external connections.
Figure 27-2 eMMC/SD/SDIOi Controller Connected to an eMMC, SD, or SDIO Card (where i = 1 to 4)Table 27-3 describes the eMMC/SD/SDIOi host controller I/O’s (where i = 1 to 4).
| Instance | Signal name | I/O(1) | Description | Reset Value(2) |
|---|---|---|---|---|
| MMC1 | mmc1_clk | I/O | External clock for eMMC/SD/SDIO card | 0 |
| mmc1_cmd | I/O | Command line | Hi-Z(3) | |
| mmc1_dat[3:0] | I/O | Data signals | Hi-Z(3) | |
| mmc1_sdcd | I | Card insertion/removal detection signal | Hi-Z | |
| mmc1_sdwp | I | Write protect detection signal | Hi-Z | |
| MMC2 | mmc2_clk | I/O | External clock for eMMC/SD/SDIO card | 0 |
| mmc2_cmd | I/O | Command line | Hi-Z(3) | |
| mmc2_dat[7:0] | I/O | Data signals | Hi-Z(3) | |
| mmc2_cd | I | Card insertion/removal detection signal | Hi-Z | |
| mmc2_wp | I | Write protect detection signal | Hi-Z | |
| MMC3 | mmc3_clk | I/O | External clock for eMMC/SD/SDIO card | 0 |
| mmc3_cmd | I/O | Command line | Hi-Z(3) | |
| mmc3_dat[7:0] | I/O | Data signals | Hi-Z(3) | |
| mmc3_cd | I | Card insertion/removal detection signal | Hi-Z | |
| mmc3_wp | I | Write protect detection signal | Hi-Z | |
| MMC4 | mmc4_clk | I/O | External clock for eMMC/SD/SDIO card | 0 |
| mmc4_cmd | I/O | Command line | Hi-Z(3) | |
| mmc4_dat[3:0] | I/O | Data signals | Hi-Z(3) | |
| mmc4_cd | I | Card insertion/removal detection signal | Hi-Z | |
| mmc4_wp | I | Write protect detection signal | Hi-Z |
For mmc2_clk, mmc3_clk and mmc4_clk signals to work properly, the INPUTENABLE bit of the appropriate CTRL_CORE_PAD_x registers must be set to 0x1 by software. This is because the eMMC/SD/SDIO controller uses the input from the pad as loopback clock, which the controller can use for read capture depending on the mode it is in.
The internal PU/PD resistors on pads mmc2_dat[7:0] can be permanently disabled. For more information, see Permanent PU/PD disabling in Control Module.